13 Marine and Littoral Biodiversity 13.1 Introduction · 13 Marine and Littoral Biodiversity 13.1...

Simandou SEIA Volume III Port Chapter 13: Marine And Littoral Biodiversity

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13 Marine and Littoral Biodiversity 13.1 Introduction This chapter presents a description of baseline marine and littoral biodiversity, and an assessment of the impacts of the Simandou Port on marine and littoral biodiversity. It is based on the definition of the port and its facilities presented in Chapter 2: Project Description, and describes habitats and important and representative taxa of fauna and flora. The chapter then assesses potential port-related impacts on marine and littoral habitats, and fauna, species of national or global conservation interest (ie species listed on the IUCN Red List of Threatened Species). The impacts are considered within the port biodiversity study area that is defined and depicted in Section 13.2.2; this excludes the terrestrial and freshwater habitats and associated taxa of flora and fauna which are considered in Chapter 12: Terrestrial Biodiversity. The impacts on marine and littoral biodiversity that are discussed in this chapter result from the following: loss of habitat through land acquisition for construction and operation of the port and its facilities and

dredging; mortality and injury to animals from vessel collisions; noise; altered water and sediment quality; artificial light; further loss of habitat due to changes in the sedimentary regime; invasive alien species; induced access and resulting pressures on natural resources; waste; and non-routine events (eg spills). There are important linkages between this chapter and a number of other topic chapters in the SEIA, both to understand the physical setting and socio-economic context for the biodiversity attributes that are described, and to define mitigation measures that will minimise impacts on biodiversity. Those of the greatest importance in this respect are: Chapter 6: Water Environment; Chapter 7: Marine and Littoral Physical Environment and Chapter 12: Terrestrial Biodiversity. This chapter considers impacts on the biodiversity value of species. Fisheries are discussed in further detail in Chapter 16: Socio-Economic and Community Baseline, Chapter 17: National Economy, Chapter 18: Employment and Economic Development, Chapter 19: In-Migration and Chapter 20: Land Use and Livelihoods. The contribution of biodiversity attributes to ecosystem services is described in Chapter 24: Ecosystem Services. This chapter is structured as follows: Section 13.2 describes the biodiversity policy context for this SEIA, and the assessment methodology

used; Section 13.3 describes the marine and littoral habitats in the area surrounding the Simandou Port and

the taxa of fauna and flora they support, to characterise marine and littoral biodiversity; designated protected areas and other areas of recognised conservation value are also identified;

Section 13.4 provides the initial assessment of impacts on biodiversity prior to mitigation;

Section 13.5 describes the approach to mitigation of impacts and the residual impacts after mitigation measures have been implemented;

Section 13.6 describes the offsets strategy for the Project; and

the chapter concludes with a short Summary of Findings in Section 13.7. Further information which supports the main text of this chapter is provided in Annexes:


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Annex 13A: Port Study Area Preliminary Marine Species List; and Annex 13B: Port Study Area Underwater Noise Scoping Report. 13.2 Approach 13.2.1 Legal and Other Requirements The assessment has been carried out with reference to the following legislation, which is specifically relevant to the conditions pertaining to biodiversity in the port study area (1). The Code for the Protection and Development of the Environment, Ordinances 045/PRG/87 and

022/PRG/89 (also known as the Environmental Code) establishes the administrative and legal framework in Guinea and sets out the fundamental legal principles to ensure the protection of environmental resources and the human environment.

Presidential Decree 199/PRG/SGG/89, made under Article 82 of the Environmental Code, sets out the

projects which require an environmental impact assessment (EIA) study. Order 990/ NRNE/SGG/90, made under Article 7 of Decree 199/PRG/SGG/89, establishes the content, methodology, and procedures to be followed when carrying out an environmental impact assessment: it states that the baseline should include a description of natural resources and that the Project’s impacts on fauna and flora, the natural environment and biological interactions should be addressed.

The Code of Protection of Wildlife and Rules of the Hunt (L/99/038/AN) sets out the legal framework for

the protection, conservation and management of wildlife and its habitats; and provides for the right to hunt to be recognised. This text also provides for some rules on hunting and aims to promote the sustainable use of animal species and ensure their sustainability for the satisfaction of human needs.

Decree 201/PRG/SGG/89, made under Articles 32 to 39 of the Environmental Code, sets out the legal

framework for the control of pollution in the marine environment, applying to all vessels within Guinean territorial waters. Article 30 prohibits the release of any hydrocarbons or mixed discharges that may impact marine fauna or flora.

In addition to its national laws, Guinea is a signatory to a number of international conventions, co-operative agreements and legal obligations concerned with environmental issues with relevance to marine biodiversity. The Convention on the Conservation of Migratory Species of Wild Animals aims to ensure the

conservation of migratory species and their natural habitats through intergovernmental cooperation. This convention was transposed into Guinean legislation via the Guinean Code of Protection of Wildlife and Rules of the Hunt.

The Convention on Biological Diversity aims to develop national strategies for the conservation and

sustainable use of biological diversity. It is often seen as the key document regarding sustainable development. This Convention has been transposed at a national level in Guinea with the Code of Protection of Wildlife and Rules of the Hunt.

The Convention on Wetlands of International Importance, called the Ramsar Convention, is an

intergovernmental treaty that provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources. This includes estuaries, deltas and tidal flats, near-shore marine areas and mangroves. Guinea has signed and ratified this Convention and it came into force in March 1993. This Convention has been transposed at a national level in Guinea with the Code of Protection of Wildlife and Rules of the Hunt.

(1) Guinean legal and regulatory requirements that are not relevant to the Simandou Ore Port development are not included here: for example, as there are no Classified Forests or other designated areas within the port study area, legislation relating to these areas is not described.


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The Convention for the Cooperation in the Protection and Development of the Marine and Coastal Environment of the Western and Central African Regions (also known as the Abidjan Convention) covers the marine environment, coastal zones and related inland waters falling within the jurisdiction of the States of the West and Central African Region, from Mauritania to Namibia inclusive. It is a comprehensive umbrella agreement for the protection and management of marine and coastal areas. Although Guinea is a party to this convention, it has not been possible to confirm, based on publicly available information, whether its requirements have been transposed into Guinean legislation.

The United Nations Convention on the Law of the Sea (UNCLOS) is the international agreement that

defines the rights and responsibilities of nations in their use of the world's oceans, establishing guidelines for the management of marine natural resources. Part XII provides guidance on the protection of the marine environment. Although Guinea is a party to this convention, it has not been possible to confirm, based on publicly available information, whether its requirements have been transposed into Guinean legislation.

The SEIA also follows international good practice as set out in IFC Performance Standard PS6: Biodiversity Conservation and Sustainable Management of Living Natural Resources. This has the following objectives: to protect and conserve biodiversity; to maintain the benefits from ecosystem services; and to promote the sustainable management of living natural resources through the adoption of practices

that integrate conservation needs and development priorities. Rio Tinto’s policies relating to Biodiversity are set out in Section 13.2.4. 13.2.2 Study Area The potentially affected landscape or seascape (1) has been determined through a consideration of impacts on marine and littoral biodiversity features. This has taken into account both land acquisition for the port (including dredged and in-river areas) and associated project components described in Section 13.2.3, and potential impacts on a wider scale (such as those resulting from pollution of marine waters, or indirect impacts on habitats from changes in the hydrodynamic regime). Most of the immediate direct impacts are expected to occur in and around the areas occupied or used for port and other project components, so the footprint of the port and associated facilities has been used to consider such impacts. To ensure the inclusion of wider-ranging impacts a precautionary approach was used to define a broader marine and littoral study area. The study area therefore encompasses the shores of Maférinyah, Ile Kakossa and Ile Kaback as well as the full extent of the access channel and dredge sediment disposal site. The port study area for marine and littoral biodiversity is illustrated by the extent shown in Figure 13.1. For the reasons described below, the port study area for this SEIA excludes areas potentially affected by the following, which are not within the port SEIA: the marine offloading facility (MOF); temporary work camps required for construction; quarries for construction materials; and road works that may be required to access camps and work fronts along the rail alignment (where

located within the port study area), or quarries.

(1) The term ‘potentially affected landscape or seascape’ is used within IFC Performance Standard 6. Guidance Note 17 explains that it is a requirement to identify the extent of project related impacts including those outside the footprint of the project area. The intention of the requirement is that project-related impacts, especially those on habitat connectivity and/or on downstream catchment areas, outside the boundaries of the project site are identified. The IFC consider this analysis to be a fundamental step in determining ecologically-appropriate mitigation options including supporting decision-making as to whether impacts should be avoided or are appropriate for offsets, the selection and design of a mitigation strategy, including offset mitigation, such that they contribute to regional-level conservation goals rather than solely site-level impacts.


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An SEIA for the MOF was submitted to the Government of Guinea in November 2011. The SEIA covered the construction and the first years of operation of the MOF as support to the construction of the main elements of the Simandou Project (port, mine and rail). Rio Tinto agreed with the Government and IFC that the categories of ancillary works listed above would be assessed on a sectoral basis in the three separate Class SEIAs. The Simandou Camps Programme Class SEIA was submitted to the Government in November 2011 and those for the Roads and Quarries Programmes in January 2012. The detailed impacts at each work location covered by the Class SEIAs is being assessed through the preparation of Site Files developed within the framework set out in the Class SEIAs, and the results will be collated in the Project-wide SEIA which will be developed later in 2012. 13.2.3 Design Basis for the Simandou Port Impact Assessment The major design features of the Simandou Port have been set out in Chapter 2: Project Description and these are used as the basis for the assessment of the port’s impacts on biodiversity. In arriving at this configuration the design and location of the port have been refined through several stages, as described in Chapter 2: Project Description and Chapter 3: Alternatives, during which biodiversity and other physical and socio-economic criteria have been considered alongside engineering and financial factors. Since no further avoidance measures were incorporated in the port design for the specific benefit of biodiversity, the resulting configuration is used as the basis for the assessment of the port’s impacts on biodiversity. The absence of further avoidance is, in part, due to limited opportunities to alter the locations of infrastructure associated with the port, but also a result of the footprint of the port development being within an area that has been greatly altered by human activities and is of low or medium marine and littoral biodiversity value. Direct loss of habitat is expected to occur within the footprint of the port infrastructure and dredged area and a surrounding area of up to 200 m on land that will be cleared for the purposes of construction. Further physical disturbance may occur due to indirect habitat loss and habitat degradation from, for example, underwater noise which may travel several kilometres from the source. The components taken into account in assessing the port’s impacts on marine and littoral biodiversity are the: dredged area (turning basin, berths and approach channel); dredged material disposal site; permanent land take for the MOF (barge landing ramp, berth and quay for up to two heavy lift vessels

with load-on, load-off capabilities, tug / pilot boat harbour, two roll-on, roll-off barge berths with ramp and a fuel berth);

export wharf; transport platform; and approach jetty. Other infrastructure within the terrestrial and freshwater study area is assessed in Chapter 12: Terrestrial Biodiversity.

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Figure 13.1Aperçu de la biodiversité marine et littorale / Marine and Littoral Biodiversity Overview

Infrastructures portuaires / Port InfrastructureCanal de dragage / Dredging ChannelSite de rejet des boues de dragage / Dredge Disposal Site

Classification des terres / Land ClassificationMangrove / MangroveRizières / Rice FieldsZone intertidale (vasières, bancs de sable , plages de sable) / Tidal Area (Mudflats, Sand Banks, Sandy Beaches)Bathymétrie / Bathymetry

Bathymétrie / BathymetryAu Large des Côtes / OffshoreCôtière et Estuarienne / Coastal and Estuarine

Projection: WGS 1984 UTM Zone 29N

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13.2.4 Policy Context 13.2.4.1 Rio Tinto’s Biodiversity Strategy and Net Positive Impact Policy Rio Tinto recognises that conservation and responsible management of biodiversity are important business and societal issues, and so has a goal to have a “net positive impact” (NPI) on biodiversity. This goal can be furthered by minimising the impacts of operations (such as the Simandou Project), and by contributing to biodiversity conservation to ensure that a region ultimately benefits as a result of the company’s presence. This policy is outlined in further detail in Chapter 12: Terrestrial Biodiversity. 13.2.4.2 The Mitigation Hierarchy This assessment of the Simandou Port’s impacts on biodiversity has been prepared to enable application of the mitigation hierarchy, which was described in the overall methodology for the SEIA in Chapter 1: Introduction. The mitigation hierarchy specifies that where a significant negative impact is identified, a hierarchy of options for mitigation is considered to identify the preferred approach. The hierarchy follows the structure of avoid, minimise / reduce, rehabilitate / restore and offset. Details of the mitigation hierarchy can be found in Chapter 12: Terrestrial Biodiversity. 13.2.4.3 The Rio Tinto Simandou Biodiversity Partner Organisations Rio Tinto has engaged a number of biodiversity partners since the development of the corporate biodiversity strategy. A description of the biodiversity partners engaged since this time and for the Simandou Project is provided in Chapter 12: Terrestrial Biodiversity. 13.2.5 Methodology 13.2.5.1 Baseline Information This assessment uses information generated from field studies conducted specifically for the Simandou Project, from reviews of existing literature on biodiversity of the region and through consultation with international and Guinean experts, as described below. Data from these sources provide the basis for the biodiversity baseline presented in Section 13.3. Survey work has been undertaken in the Guinean Coastal Region to evaluate areas being considered as locations for the port development since 2008, including biodiversity surveys both in the wider Guinean Coastal Region and in the specific area more recently selected for the port development (see Table 13.1). Data from both the wider Guinean Coastal Region and the identified port area have been presented to provide both regional context and specific local information. An on-going programme of data collection will provide information to support the effective implementation of mitigation measures. In addition, some survey data from the wider region (eg fish and invertebrate surveys) can reasonably be extrapolated to the current project site given the known or likely habitat distribution. Digitisation of land cover in the port area was carried out manually using high-resolution imagery (0.5 m resolution) from 2010 / 2011. The process involved the designation of land cover classifications using knowledge of existing land cover in the area, with added input from individuals who have visited the site and was further verified through comparison of the aerial imagery with photographs taken at various locations. The digitisation process was carried out at a scale of approximately 1:1 000 to allow for the data to be captured at a suitable level of detail for the assessment.


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Table 13.1 Summary of Biodiversity Baseline Surveys Completed within the Guinean Coastal Region and at the Port Study Area

Topic Period and Timeframe Level of Effort within the Study Area Sampling Locations

Survey Methodology Field team

Mangrove forest

15 March to 5 April 2008 (dry season only)

56 stations within six different mangroves classes

Vegetation:

Species identification

Relative dominance and relative density of the species

Stem parameter measurements (diameter at breast height – DBH)

Canopy measurements

Leaf Area Index (LAI)

Yélitono Island (south of the Forécariah River)

Three sizes of fixed area radius plots

Measurements of biophysical parameters (DBH, LAI, etc)

Satellite image processing - Yélitono Island

Environnement Illimité in collaboration with mangrove specialist John M. Kovacs (Nipissing University)

15 March to 5 April 2008 (dry season only)

Microfauna of the mangrove:

Species identification

Density of the microfauna of the mangrove

Yélitono Island Field sample (plots) Environnement Illimité

November 2010 7 526 ha of mangrove forest were mapped based on 2010 optical data.

Kaback Satellite image interpretation Environnement Illimité

SNC-Lavalin Environment

Sea turtles 6 to 9 February 2008

30 September 2008

Meeting with the chief of port and fishermen in the villages of Sourinéné, Sibicobi, Ounié and Salatougou to integrate traditional knowledge.

n/a Interviews with the chief of port and fishermen

Environnement Illimité


17 days in October 2011

26 days in November / December 2011

18 days in January / February 2012

Villager/fisher surveys conducted in 9 villages.

12 night-time surveys and 38 daytime surveys (among select beaches over 5 months); 19 beaches characterised; 8 camera traps deployed on Matakang beaches.

Nets deployed during 4 days in Matakang and 5 days in Morebaya.

Forécariah and Morebaya estuaries; Beaches of Kaback and Kakossa Peninsula

Village meetings examining turtle bycatch and nesting

Beach habitat characterization

Beach nesting surveys

Netting surveys

Camera trapping

DNA sampling


Guinean specialist from Centre National des Sciences Halieutiques de Boussoura (CNSHB)


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Benthic invertebrates

13 March to 13 April and 17 May to 12 June 2008 (dry season)

25 September to 16 October 2008 (wet season)

120 stations - 65 in marine areas and 55 in estuarine areas (dry season)

75 stations - 43 in marine areas and 32 in estuarine areas (wet season)

Yélitono-Mabala Islands

Grab sampling

Laboratory analysis


Benthic invertebrate Identification: Institut des Sciences de la Mer (ISMER) – Laboratory of Philippe Archambault


19 stations (dry season)

19 stations (wet season)

Trawl sampling

Laboratory analysis

22 September to 18 October, 2011

40 stations Offshore of Kaback

Grab sampling

27 March to 4 April 2012 (dry season)

10 stations along the proposed dredge channel in the Morebaya River and Estuary

9 stations at the disposal site offshore Kaback

Morebaya river and Estuary

Offshore Kaback

Grab sampling

Fish 15 March to 5 April and 15 May to 12 June 2008 (dry season)

45 fishing stations - 26 in estuarine areas and 19 in marine areas (dry season)

Estuaries and offshore of Yélitono-Mabala Islands

Gillnets, trapnets, seine fishing stations in riverine and estuarine areas.

Long experimental gillnets and trawl fishing stations in marine environment.



25 September to 16 October 2008 (wet season)

42 fishing stations - 23 in estuarine areas and 19 in marine areas (wet season)

June 12 to June 21, 2011 (dry season)

11 fishing stations in marine areas and 2 stations in the mangrove channel

Offshore of Kaback and in the mangrove channels of Kaback

Local seine net used by Guinean fishermen in the marine area

Gillnets and trapnets in the mangrove channels

19 April to 3 May 2012 Surveys at two fishing ports: Touguiyiré and Dabonkhoré

General surveys along the Morébaya and Touguiyiré rivers

As per effort level column

Survey Environnement Illimité



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Marine mammals

6 to 9 February 2008

30 September 2008

Traditional knowledge:

Meeting with the chief of port and fishermen in the villages of Sourinéné, Sibicobi, Ounié and Salatougou to integrate traditional knowledge

Literature review

n/a Interviews with the chief of port and fishermen

Literature review:

IUCN / Wetlands Int. report on manatee in Sierra Leone

UNEP report on preliminary conservation strategy for the West African manatee

Thesis on socio-ecological value of manatee in Guinea

Guinea Republic / Wetland Int. Report on 2002 survey of manatee in Guinea



Ad hoc observations from June 2011 to January 2012

Observations at fixed points for manatee between September 22 and October 8, 2011.

Transects during team transport from Conakry to Port site

8 stations were monitored to observe manatee in the study area

Offshore of Kaback

In the Forécariah and Morebaya river and in the mangrove channels of Kaback Island.

Ad hoc observations during transport between Conakry and Kaback

Field observations using fixed points and zodiac observations for manatee


Fish and oyster ecotoxicology

15 March to 5 April 2008 and 15 May to 12 June 2008 (dry season only)

9 composite samples of oyster (Crassostrea gasar)

9 composite samples of fish (Pseudotolithus elongatus)

n/a. Fish and oyster tissue sampling to evaluate level of contamination

Laboratory analysis


Laboratory analysis - Maxxam Analytics


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13.2.5.2 Values Assessment: Identification of Habitats and Species of Biodiversity Value Based on the information collected from literature, surveys, and consultation with experts as described above, the SEIA has assigned a value to the biodiversity attributes of the port study area. The values assessment procedure is described in the box below, and it has been carried out in conjunction with the Simandou Project’s broader biodiversity action planning. These values are used as a criterion in assessing impacts (see box in Section 13.2.5.6 and Tables 13.2 and 13.3). The species list provided in Annex 13A: Port Study Area Preliminary Marine Species List – Marine and Littoral Species (1) indicates the values assigned according to this methodology. 13.2.5.3 Prioritisation of Habitats and Species of Biodiversity Value The values assessment methodology allows, in cases where a large number of high and medium value taxa are identified as occurring or potentially occurring in a study area, for a further prioritisation step as described in the box in Section 13.2.5.6. This step has not been used for the marine and littoral biodiversity in the Simandou Port SEIA due to the relatively small number of high and medium value taxa species known or considered likely to occur. The values assessment and prioritisation of biodiversity attributes used in the SEIA is fundamental to further Biodiversity Action Planning (BAP) activities, after further development as required for the BAP’s needs. 13.2.5.4 Assessment of Impact Significance Impacts of the Simandou Port on marine and littoral biodiversity were assessed using the overall SEIA impact assessment methodology set out in Section 1.4, which was tailored to enable completion of the biodiversity impact assessment matrix presented in Table 13.2 and Table 13.3. Impacts were assessed for the relevant phase of the project (construction and / or operation). The port will be owned jointly by the Project and the Government of Guinea in a special purpose infrastructure company, and will be transferred to full Government ownership 40 to 50 years after opening when the cost of the port has been fully amortised. There is no plan to remove the port infrastructure once the Simandou Project has ended, and therefore closure and decommissioning phases and activities are not included in this SEIA. The accompanying mine and railway SEIAs followed a prioritisation process for habitats and species of biodiversity value. However, due to the smaller number of high value marine and littoral habitats and associated species in the port study area, this impact assessment considers all habitats and taxa recorded or considered highly likely to be present based on their known habitat preference. The magnitude of potential impacts is defined in Table 13.2 for habitats and Table 13.3 for taxa, which illustrate how the significance of an impact is assessed by cross-referencing the value of a biodiversity attribute with the predicted magnitude of the impact. Impacts are categorised as not significant, minor, moderate, major or critical. 13.2.5.5 Mitigation Mitigation is described in Section 13.5 according to the sequence of the mitigation hierarchy (see Section 1.4.3.4 and Section 13.2.4.2). The measures set out are based on industry best practice and Rio Tinto policies and standards. In many cases a specific measure is stated that will be carried forward as a project commitment in the SEMP; in other cases, further work will be required to consider various mitigation options before selection and implementation of the option that is the most reasonably practicable.

(1) This is a preliminary version of the species list being finalised in the on-going work to develop an offset strategy for the overall Simandou Project.


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13.2.5.6 Residual Impacts Residual impacts are presented on the assumption that mitigation measures have been implemented as per the commitments made by the project (see Section 13.5). Impacts are discussed quantitatively where possible; where this is not possible impacts are described qualitatively.

Value Assessment of Habitats and Species for the Simandou Port Habitats and species were assigned to broad categories of ‘value’ based on the standard conservation priority setting principles of vulnerability and irreplaceability. The methodology draws on a preliminary values assessment carried out by BirdLife International in 2008 and reviewed by the Simandou Biodiversity Partners. Habitats There is no systematic assessment of habitat threat status at the global or Guinean national level, so the habitat values assessment was based on expert consultation and review of peer-reviewed literature. The assessment considered irreplaceability (measured by the total area covered by a particular vegetation type globally) and vulnerability (measured inter alia by the proportion of the total distribution of a particular habitat type that is included within protected areas). This followed the rationale that habitat types that are largely found outside of protected areas are more vulnerable than those that are well represented within protected areas (even 'paper parks' appear to have conservation benefits (1)). Because sufficient information to apply the vulnerability criterion was not available for any vegetation community at the time of the assessment, a provisional assessment of conservation value (on an ascending scale of ‘low, medium, high’) was made for each habitat type, based on expert judgement (including consultation of the Simandou Biodiversity Partners) and the principles of vulnerability and irreplaceability, with a rationale given in each case. In line with standard SEIA practice, a ‘negligible’ category was added to the impact assessment matrix, as presented in Table 13.2. Fauna and Flora Species were assessed based on vulnerability (eg level of extinction risk) and irreplaceability (eg does the species have a restricted range?). Extinction risk was defined based on the IUCN Red List of Threatened Species (IUCN 2011). The National Monograph on the Biological Diversity of Guinea (Ministère des Travaux Publics et de l’Environnement 1997) was also consulted. ‘Restricted range’ was defined as: all terrestrial and freshwater fauna species with a range of less than 50 000 km2; all marine fauna with a range of less than 100 000 km2 (2); and, all plant species found globally at fewer than 10 sites (3). Categories of value were defined as follows: ‘High’ – species assessed by IUCN as Critically Endangered or Endangered, or species having a restricted range

based on the criteria defined above (4); ‘Medium’ – species not meeting the criteria for ‘high’, and assessed by IUCN as Vulnerable, Near Threatened or

Data Deficient; and ‘Low’ – species not meeting the criteria for ‘medium’ or ‘high’. In line with standard SEIA practice, a ‘negligible’ category was added to the impact assessment matrix. Prioritisation of Biodiversity Attributes As the values assessment identified only a small number of high and medium value taxa occurring or potentially occurring in the port study area, the further prioritisation step carried out for the Simandou Mine and Ore Railway was not required for the Simandou Port. If it had been necessary, high and medium value taxa defined as Critically Endangered, Endangered, Vulnerable, and restricted range taxa where the Study Area potentially holds a notable proportion of the global population would have been prioritised, with in most cases the definition of a notable proportion based on spatial analysis (ie taxa with more than 1% of their global distribution within the study area being excluded). Particular attention was given to Critically Endangered and Endangered taxa, especially those that are wide-ranging and/or whose population distribution is not well understood; expert judgement was used to refine the initial spatial analysis in some cases.

(1) Bruner, A. G., Gullison, R. E., Rice, R. E. & da Fonseca, G. A. B. (2001). Effectiveness of parks in protecting tropical biodiversity. Science 291: 125-128. (2) This definition of restricted range for terrestrial, freshwater and marine fauna is in line with IFC Performance Standard 6 guidance. (3) This definition of restricted range for plants was recommended by Royal Botanic Gardens, Kew. (4) This definition of ‘High value’ aligns with IFC PS6 Critical Habitat criteria that focus particularly on Critical, Endangered and restricted-range species.


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Table 13.2 Habitat Impact Assessment Criteria

Magnitude of Impact

Habitat Value

Negligible Small Medium Large

Impact is within the normal range of day to day variation.

Affects a small area of habitat, but without the loss of viability / function of the habitat.

Affects a sufficient proportion of the habitat and the viability / function of part of the habitat or the entire habitat is reduced, but does not threaten the long-term viability of the habitat or species dependent on it.

Affects the entire habitat or a sufficient proportion of the habitat, where the viability / function of the entire habitat is reduced and the long-term viability of the habitat and the species dependent on it are threatened.

Negligible

Habitats not globally, regionally or nationally protected or listed. Habitats which have negligible interest for marine and littoral biodiversity.

Not Significant Not Significant Not Significant Not Significant

Low

Habitats not globally, regionally or nationally protected or listed. Habitats which are very common and widespread in the West African coastal region or habitats generally modified or degraded by anthropogenic activities, or with low conservation significance in expert opinion.

Not Significant Not Significant Minor Moderate

Medium

Habitats locally rare, small or scattered; habitats which include sets of species uncommon in Guinea; habitats supporting species which have specific adaptations to that habitat; and habitats with significant richness in biodiversity. Includes any low value habitats used by medium value species as important breeding, feeding areas or migration routes.

Not Significant Minor Moderate Major

High

Habitats supporting a set of unique or important species; habitats already threatened within the coastal region; habitats with a limited global extent. Also includes habitats used by high value species as important feeding or breeding areas or potential migration routes.

Not Significant Moderate Major Critical


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Table 13.3 Species Impact Assessment Criteria

Magnitude of Impact

Species Value

Negligible Small Medium Large

Impact is within the normal range of day to day variation.

Affects a small proportion of a population but does not substantially affect other species dependent on the feature or the population of the species itself.

Affects a sufficient proportion of a species population that it may bring about a substantial change in abundance and / or a reduction in the distribution over one or more generations, but does not threaten the long-term viability of that population or any population dependent on it. The size and cumulative effect is also important such that a medium magnitude impact multiplied over a wide area would be regarded as a large magnitude impact.

Affects an entire population or species in sufficient scale to cause a substantial decline in abundance and / or change in distribution beyond which natural recruitment (reproduction, immigration from unaffected areas) may not return that population or species, or any population or species dependent upon it, to its former level with several generations, or when there is no possibility of recovery.

Negligible No specific value or importance attached to the species.

Not Significant Not Significant Not Significant Not Significant

Low Species not protected, listed as widespread or abundant and is not included in the criteria for high or medium value.

Not Significant Not Significant Minor Moderate

Medium

Species included on the IUCN red list of threatened species as Vulnerable (VU), Near Threatened (NT), or Data Deficient (DD) species (IUCN 2011). Not included in the criteria for high value species.

Not Significant Minor Moderate Major

High

Species included on the IUCN red list of threatened species as Critically Endangered (CR) or Endangered (EN) species (IUCN 2011), Species having a particularly Restricted Range (ie marine species having a distribution range less than 100 000 km2).

Not Significant Moderate Major Critical


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13.3 Characterisation of Baseline Biodiversity 13.3.1 Introduction Guinea is important to global and regional biodiversity conservation. Not only does it partly lie within the regional biodiversity hotspot known as the “Guinean Forests of West Africa” (1) but it also hosts the world’s largest remaining West African chimpanzee (Pan troglodytes verus) populations (2). Guinea is home to the headwaters of several major West African rivers and the largest remaining mangrove forests in the region. Guinea’s biodiversity is subject to a number of threats, one of the greatest of which is loss of natural habitat due to expansion of shifting agriculture. Other major threats to habitats include hunting, logging and mining. The Simandou Port will be located on the east bank of the Morebaya River, approximately 5 km upstream of the river mouth within the Maférinyah Sub-Prefecture of Forécariah Prefecture and Kindia Region. The port is situated in a narrow low-lying coastal plain bounded by the Morebaya River to the west and north and a tributary of this river (the Sangbon) to the south. The biodiversity study area, defined as the basis for the assessment of the port’s impacts on biodiversity and described in Section 13.2.2 and shown in Figure 13.1, encompasses the shores of Maférinyah, Ile Kakossa and Ile Kaback as well as the full extent of the access channel and dredge sediment disposal site. This section provides a characterisation of the marine and littoral habitats within the biodiversity study area, and the flora and fauna that they support. The information used to develop this characterisation has been obtained from: literature reviews and desk studies of published literature, other publicly-available information including

the range maps and other species-specific information in the IUCN Red List of Threatened Species (3), and some unpublished data; and

the findings of the extensive survey programme being carried out by the Project, summarised in Section 13.2.5.

In this section photographs are used to supplement description of habitats and species. The section is set out as follows: Section 13.3.2 provides a general overview of the ecology of the offshore, coastal and littoral area

around the port providing context for the more detailed characterisation that follows;

areas of conservation interest (ie all sites protected by Guinean law, other sites recognised by international bodies, proposed protected / designated sites, and other areas which have been identified through surveys and studies undertaken for the Project as being of biodiversity importance) are described in Section 13.3.3; and

habitats are characterised and information is provided on flora and fauna in Sections 13.3.4 – 13.3.6.

High value species, and medium value species which in expert opinion are considered to be of elevated conservation concern due to the specific threats to the species within the region, are highlighted individually in Section 13.3.6. A preliminary list of all species (high, medium, low, and negligible value) known or considered to be potentially present in the biodiversity study area is presented in Annex 13A: Port Study Area Preliminary Marine Species List, which includes a summary of whether the

(1) Biodiversity hotspots are recognised as the richest and most threatened reservoirs of life on earth. Available at http://www.biodiversityhotspots.org/xp/hotspots/west_africa/Pages/default.aspx (2) Kormos R & Boesch C (2003). Regional Action Plan for the Conservation of Chimpanzees in West Africa. IUCN/SSC Primate Specialist Group and Conservation International, Washington DC. (3) Throughout this section, any information that has been derived from surveys or studies carried out in relation to the Project is referred to as such, further identified where appropriate by the year in which the work was undertaken. Specific information from published and publicly-available sources is accompanied by a reference in a footnote, and information obtained from the IUCN Red List of Threatened Species, is denoted in the text as IUCN Red List of Threatened Species v 2011.2. The full citation, which is applicable to all instances in which this source is mentioned, is: IUCN (2011) IUCN Red List of Threatened Species, Version 2011.2 <www.iucnredlist.org>, last accessed between February and March 2012.


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biodiversity study area for the Simandou Project as a whole is considered likely or not to support more than 1% of the global population of each species.

13.3.2 Overview of the Port Biodiversity Study Area The port biodiversity study area comprises several habitat types, which are interconnected in terms of both physical and biological processes. As such it is difficult to delineate the offshore or coastal areas. However, for the purposes of this assessment the offshore area is considered to be in relatively deep water (>20 m), where wave induced sediment movement is limited. The coastal area is considered to be in water depths of generally less than 20 m although small isolated deeper areas are present within this zone. It is noted, however, that many species will move freely between the offshore and coastal habitats. For the purposes of this assessment the port biodiversity study area has been separated into seven main habitat types, and these are considered in terms of subtidal marine and estuarine habitats and the intertidal littoral habitats. Habitat types considered are: offshore pelagic, offshore benthic, coastal and estuarine, intertidal mudflats and sandbanks, rocky shore, sandy beach and mangroves. Figure 13.1 illustrates the marine and littoral biodiversity study areas. The offshore pelagic habitat is widespread and fairly homogeneous. The offshore parts of the study area may be used occasionally by migratory species of conservation importance, such as whales and sea turtles but in general, the offshore environments are less productive and less diverse than coastal and estuarine habitats in the region. Offshore benthic habitat is also widespread and tends to supports a lower diversity of fish species than benthic habitats closer inshore. Some high value species may be found in these offshore habitats but are not typically restricted to them. Shallow coastal and estuarine waters, such as those found in and around the port area, typically exhibit high productivity due to nutrient input from the rivers and land, and therefore these areas tend to support a high biomass of fish. This nearshore fish community contains the majority of the species that are targeted by fisheries in the area, although offshore waters do have some commercial importance due to the seasonal presence of targeted pelagic fish species. Several threatened fish species and known to occur in these waters (see Section 13.3.6.5). The coastal and estuarine zone also provides important spawning and nursery areas for juvenile fish and invertebrates, and feeding areas for fish, birds, marine mammals and sea turtles. The most threatened species within the marine and estuarine environment are bottom dwelling species from the shark and ray family, which live predominantly in benthic habitat in coastal waters. Mangroves represent a key littoral habitat which is quite widespread in the port study area. These highly diverse and complex habitats are used for foraging, resting, nursery and refuge areas by invertebrates, juvenile fish, a wide variety of migratory and endemic birds and some larger animals such as the West African manatee (Trichechus senegalensis). Mangroves not only help to sustain Guinea’s fisheries but are a major source of nutrients to coastal habitats. Other littoral habitats in the area include intertidal mudflats, sandbanks and sandy beaches. These habitats are mobile and dynamic systems that are sensitive to changes in local sediment, current and tidal regimes. All three habitat types provide resting and feeding areas for migratory birds and the sandy beaches have the potential to support nesting turtles. However, only small numbers of turtles have been reported from surveys carried out from November to January indicating the beaches are not globally significant nesting areas at that time. The results of further surveys will feed into management plans as required. 13.3.3 Areas of Conservation Interest There are no nationally or internationally designated conservation areas within the port study area. The nearest protected area is Ile Blanche, which is located 40 km northwest of the proposed port. Ile Blanche is a rocky island with almost no vegetation that is classified as a Ramsar site and recognised as an Important Bird Area due to it being used on a regular basis by at least 1% of the biogeographic population


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of Royal tern (Sterna maxima). This bird species (1) tends to congregate in large numbers in one location during at least one phase of its life cycle. Ile Blanche is also known to support nesting Olive Ridley sea turtles (Lepidochelys olivacea) (2), and possibly other sea turtle species which may nest on its sandy beaches. In addition, the Melacorée Estuary, located approximately 35 km south of the Morebaya River and outside the port study area, has been proposed as a Marine Protection Area (MPA). The current status of the MPA is unknown. The Melacorée Estuary serves as a fish spawning and feeding site, continental deposit, and bird migration area. The key habitats on this site are the primary mangrove, the sand banks and beaches, the remains of coastal forests and the mud flats. Given that both Ile Blanche and the Melacorée Estuary are outside the port study area, impacts on protected areas have not been considered further. 13.3.4 Habitat Characterisation The following sections present a characterisation of the offshore, coastal and littoral habitats within the port biodiversity study area. Terrestrial and freshwater habitats and associated taxa of flora and fauna are considered in Chapter 12: Terrestrial Biodiversity. For each habitat, the following information is presented: a description of the habitat and ecology including species of conservation interest; the distribution of the habitat within the biodiversity study area; the global and or regional relevance of the habitat; the threats faced by the habitat and the extent of degradation in the Guinean context; and the presence of invasive species. Each habitat is then assigned a value based on the criteria defined in Table 13.4. This characterisation is provided for all habitats known to occur within the biodiversity study area. Table 13.4 Habitat Value Criteria

Negligible Habitats not globally, regionally or nationally protected or listed. Habitats which have negligible interest for marine and littoral biodiversity.

Low Habitats not globally, regionally or nationally protected or listed. Habitats which are very common and widespread in the West African coastal region or habitats generally modified or degraded by anthropogenic activities, or with low conservation significance in expert opinion.

Medium Habitats locally rare, small or scattered; habitats which include sets of species uncommon in Guinea; habitats supporting species which have specific adaptations to that habitat; and habitats with significant richness in biodiversity. Includes any low value habitats used by medium value species as important breeding, feeding areas or migration routes.

High Habitats supporting a set of unique or important species; habitats already threatened within the coastal region; habitats with a limited global extent. Also includes habitats used by high value species as important feeding or breeding areas or potential migration routes.

13.3.4.1 Offshore Pelagic Habitat Description and Ecology The offshore pelagic habitat refers to the water column in areas with water depths greater than 20 m. As described in Chapter 7: Marine and Littoral Physical Environment, the Guinea Current stretches along Africa’s Atlantic coast from Guinea-Bissau to Angola (3), and is characterised by upwelling from July to September and again but to a lesser extent between December to January. Both the major and minor (1) Peter Robertson. Important Bird Areas in Africa and associated islands – Guinea. (2) The Annotated Ramsar List: Guinea 16/10/2007. Available at http://www.ramsar.org – last accessed 15 August 2011. (3) US Aid (2007). Guinea Biodiversity and Tropical Forests 118 / 119 Assessment. Prepared by the Biodiversity Analysis and Technical Support Team.


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upwelling drive important pelagic species into the upper layers of the water column. The zones of upwelling are predominantly to the north or south of Guinea (1), although local upwelling near Guinea may also occur. Guinea’s large, shallow continental shelf, which extends up to 130 km from the coast means that upwelling occurring at the shelf edge has little influence on coastal waters. Instead the area is almost completely dependent on terrestrial inputs of nutrients resulting in a decrease in productivity and richness away from the coast (2). Offshore pelagic species tend to associate with the colder waters further offshore and to the north of the country, areas that are distant from the study area (3). Surface water temperatures are warm throughout the year, ranging from 26 to 30°C, although waters further offshore are colder from December through to May (4). Fluctuations in salinity are associated with seasonal rainfall near the coast. Global and / or Regional Relevance The pelagic environment offshore Guinea is not distinct from offshore waters elsewhere in the region and these habitats can be considered widespread. Offshore waters are used for commercial fishing, with vessels mainly from industrialised international fleets. Threats and Extent of Degradation in Guinea Context The only serious threat to these habitats is from overfishing, mainly by industrialised international fleets. Industrial fishing is concentrated in the more productive offshore waters in the northwest of Guinea’s Exclusive Economic Zone (EEZ); habitats within the study area are less heavily exploited. Presence of Invasive Species There is no evidence of any alien or invasive species within the study area. Key Fauna Species Associated with the Habitat Several high and medium biodiversity value species are likely to occur in the offshore pelagic habitat in the project area including up to 20 species of cetacean, five species of sea turtles and a variety of fish and sharks. In addition, a number of lower biodiversity value fish / sharks and bird species may also be present and many marine fish / shark species have not been assessed by the IUCN and their conservation status is currently unknown. Section 13.3.6 provides information on species in the port study area; a preliminary list of species known and likely to occur can be found in Annex 13A: Port Study Area Preliminary Marine Species List.

Offshore Pelagic Environment – Low Value This habitat is considered to be of low value as it is not protected and is geographically widespread in the West African coastal region. It is not considered to have special importance for any high or medium value species that may use this habitat. Criteria for high, medium and low value species are defined in Table 13.3 and the species are discussed further in Section 13.3.6.

(1) UNEP (2004). Abe, J., Wellens-Mensah, J., Diallo, O.S. and C. Mbuyil Wa Mpoyi. Guinea Current, GIWA Regional assessment 42. University of Kalmar, Kalmar, Sweden. Available at http://www.unep.org/dewa/giwa/areas/reports/r42/giwa_regional_assessment_42.pdf (2) Atlas Infogéographique de la Guinée Maritime (3) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (4) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes.


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13.3.4.2 Offshore Benthic Habitat Description and Ecology The offshore benthic habitat refers to the seabed habitat in areas where water depths are greater than 20 m. The majority of Guinea’s continental shelf extends away from the coast at depths of 20 m to 60 m. The seabed substrate is predominantly sandy, but interspersed with underwater canyons that accumulate muddy sediments. Sediment becomes increasingly fine in the offshore direction, following riverine channels. In water depths beyond 60 m, the shelf seabed is dominated by sandy muds. The edge of the continental shelf lies in water depths of approximately 100 m (1). Global and / or Regional Relevance The benthic environment offshore Guinea consists of habitats that can be considered widespread. Benthic habitats support a variety of species that are important food sources for fish / sharks and marine mammals; however, many fish / sharks and marine mammals are wide ranging and therefore are transitory through pelagic areas rather than being resident in one place for long periods of time. Threats and Extent of Degradation in Guinea Context The only serious threat to these offshore habitats is from overexploitation through targeted demersal fishing, mainly by industrialised international fleets. Offshore benthic habitats within the study area are not threatened in the context of Guinea. Presence of Invasive Species There is potential for alien or invasive species to occur within this habitat type, but their presence has not been identified in the study area. Key Fauna Species Associated with the Habitat No high or medium biodiversity benthic fauna have been identified. However, several high and medium biodiversity value fish species may occur, including a number of threatened elasmobranchs (sharks and rays). Other species of less conservation concern may also be present including commercially important species of deep sea crab and shrimp (2) as well as fish and invertebrate species with little or no commercial value. In addition, many marine fish and invertebrate species have not been assessed by the IUCN and their conservation status is currently unknown. Section 13.3.6 provides information on species in the port study area; a preliminary list of species known and likely to occur can be found in Annex 13A: Port Study Area Preliminary Marine Species List.

Offshore Benthic Environment – Low Value This habitat is considered to be of low value as it is not protected and is geographically widespread in the West African coastal region. It is not considered to have special importance for any high or medium value species that may use this habitat. Criteria for high, medium and low value species are defined in Table 13.3 and the species are discussed further in Section 13.3.6.

13.3.4.3 Coastal and Estuarine Habitat Description and Ecology The coastal and estuarine habitat refers to the water column and seabed in areas with water depths less than 20 m. For the purposes of this assessment the coastal and estuarine habitats are considered together (1) Atlas Infogéographique de la Guinée Maritime (2) Social and Environmental Baseline Studies (2011).


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given the wide range of salinities that characterise both the coastal and estuarine areas and the range of species likely to inhabit both habitats. Shoreline habitats such as sandbanks, beaches, mudflats and mangroves are considered separately in Sections 13.3.4.4 – 13.3.4.7. The main nutrient inputs to Guinea’s waters derive from estuaries and coastal vegetation in the form of sediments and organic matter (1). Guinea’s many rivers continuously discharge nutrients, resulting in very high productivity concentrated close to the coast (2). The large inputs of freshwater and sediment in this region result in permanently turbid and brackish waters that extend the typically estuarine conditions into the coastal zone (3). Subtidal sediments in the study area are very rich and highly mobile, subject to constant dispersal offshore and replenishment from the coast (4). These sediments are predominantly fine to very fine sand, with areas of coarser sand and very fine gravel within the estuaries where water movement is greatest (5). Wave action in the shallow waters also results in very high turbidity, especially during the rainy season. As a result, Guinea’s coastal waters are known as the most turbid in this region (6). The sediment plume discharged from Forécariah River drifts northwards and contributes to turbidity in the Project’s coastal zone, while turbidity was found to decrease in the mouth of the Morebaya River (7). On-going erosion and transport of sediment in the dynamic coastal environment results in a heterogeneous bed texture (8). Increased rainfall and river discharge during the rainy season results in a lowering of salinity close to the coast. Global and / or Regional Relevance Guinea’s coastal waters are highly productive and diverse and these habitats have huge importance in terms of local and regional fisheries. Such habitats are found throughout the region extending over kilometres of seafloor along the West African coast. Threats and Extent of Degradation in Guinea Context Threats to these habitats include overexploitation through targeted fishing, mainly by local and artisanal fisheries. Fishing in these waters is intensive. Degradation of these habitats as a result of onshore development, through altered sediment and hydrological regimes and changes to water quality also constitutes an existing threat. Presence of Invasive Species There is potential for alien or invasive species to occur within this habitat type, but their presence has not been identified in the study area. Key Fauna Species Associated with the Habitat High and medium biodiversity value marine mammals (cetaceans and manatee), sea turtles and fish / sharks may all be present in the coastal and estuarine habitats. Other marine mammals, fish, bird and benthic species of less conservation concern will also be present. In addition, many marine fish and invertebrate species have not been assessed by the IUCN, and their conservation status is currently unknown. On-going work on the Red List assessment of all West African shore fishes over the next two years will help inform the Project’s future monitoring and mitigation activities. Section 13.3.6 provides information on species in the

(1) Atlas Infogéographique de la Guinée Maritime (2)Social and Environmental Baseline Studies (2011). (3) Baran E. (2000). Biodiversity of Estuarine Fish Faunas in West Africa. Naga, The ICLARM Quarterly Vol. 23, No.4, p.4-9. (4) Atlas Infogéographique de la Guinée Maritime (5) Social and Environmental Baseline Studies (2012). (6) Capo S., Brenon I., Sottolichio A., Castaing P. & Le Goulven P. (2009). Tidal sediment transport versus freshwater flood events in the Konkouré Estuary, Republic of Guinea. Journal of African Earth Sciences 55: 52–57. (7) Social and Environmental Baseline Studies (2012). (8) Social and Environmental Baseline Studies (2012).


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port study area; a preliminary list of species known and likely to occur in the area can be found in Annex 13A: Port Study Area Preliminary Marine Species List.

Coastal and Estuarine– Medium Value This habitat is considered to be of medium value since although this habitat is geographically widespread it supports species that have specific adaptations to the habitat and is used by a range of high and medium value species. Criteria for high, medium and low value species are defined in Table 13.3 and the species are discussed further in Section 13.3.6 below.

13.3.4.4 Intertidal Mudflats and Sandbanks Habitat Description and Ecology The coast of Guinea is characterised by a large tidal range, creating diverse intertidal habitats (1). These fragile habitats are sensitive to climatic and hydrological conditions since the dynamics of sediment transport between the mudflats, sandbanks and estuary mouths continually shift in response to cyclical changes in prevailing winds and rainfall (2). Sandbanks, consisting of coarse sands, occur along the coast in areas of high energy sedimentation and are highly mobile (3). Those outside the Morebaya River are actively migrating due to seasonally driven processes and / or coastal change. Figure 13.2 shows examples of intertidal habitat in the port study area. Figure 13.2 Examples of Intertidal Habitat – Sand Bank (left) and Sandy Beach (right)

Global and / or Regional Relevance Intertidal mudflats and sandbanks are widespread within the region but less common locally. Threats and Extent of Degradation in Guinea Context Degradation of these habitats has resulted from development in the region, and particularly from the loss of mangrove through conversion to agricultural land which has altered the local sediment and hydrological regimes, resulting in changes to the extent, distribution and quality of mudflat and sandbank habitats.

(1) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (2) Atlas Infogéographique de la Guinée Maritime (3) Social and Environmental Baseline Studies (2012).


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Presence of Invasive Species There is potential for alien or invasive species to occur within this habitat type, but their presence has not been identified in the study area. Key Fauna Species Associated with the Habitat Fish including shark species of high biodiversity value may be associated with the intertidal habitats in the study area. Other species of less conservation concern may also be present. For example, intertidal mudflats in the study area are used by a variety of native and migratory birds, including the Eurasian curlew (Numenius arquata) which is a medium value species. The abundant invertebrate community of the intertidal zone provides an important food source for birds and fish and can support them in great numbers. Section 13.3.6 provides information on species in the port study area; a preliminary list of species known and likely to occur can be found in Annex 13A: Port Study Area Preliminary Marine Species List.

Intertidal Mudflats and Sandbanks – Medium Value Intertidal mudflats and sandbanks are considered to be of medium value as they are locally rare (although alternatives exist in the wider geographic region) and they support some species with specific adaptations to the habitat type, including some that are of conservation interest. Criteria for high, medium and low value species are defined in Table 13.3 and the species are discussed further in Section 13.3.6 below.

13.3.4.5 Rocky Shore Rock substrata in intertidal areas provides stable habitat for colonisation by a large variety of invertebrates and marine plants which provide shelter and food for a range of fish species. However, there is very little rocky shore habitat within the port study area and this habitat is not considered within the impact assessment. 13.3.4.6 Sandy Beach Habitat Description and Ecology Sandy beaches occur along the Guinean coast in areas of high energy sedimentation. There are several sandy beaches located around the mouth of the Morebaya River (see Figure 13.1). An example of a sandy beach from within the port study area is shown in Figure 13.3. Sandy beaches can provide nesting habitat for sea turtles, although only very low numbers of nesting turtles were reported from recent surveys undertaken in the study area. The sandy beaches in the port study area are not considered to be globally important nesting beaches; they do not offer high quality nesting habitat and are disturbed by local communities. However, the Project will undertake additional surveys during the August - September nesting season for key turtle species. Sandy beaches may also provide nesting, roosting and feeding habitat for local and migratory bird species.


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Figure 13.3 Sandy Beach South of Sangbon (Ile Kaback)

Global and / or Regional Relevance Sandy beaches are relatively widespread within the region. Similar sandy habitats supporting similar species are likely to be found in numerous locations along the coast of West Africa. Threats and Extent of Degradation in Guinea Context Degradation of sandy beaches has resulted from development in the region, and particularly from the loss of mangrove habitat through conversion to agricultural land, which has altered local sediment and hydrological regimes and changed the extent, distribution and quality of associated habitats. Erosion caused by loss of coastal vegetation may be altering coastlines and beach morphology in the area. Changes in the coastline can be observed along the western shoreline of Kaback (1). Within the study area, coastal villages along most of the beaches result in threats to the sandy beach habitats through occupation, poaching and disturbance pressures (2). Presence of Invasive Species There is potential for alien or invasive species to occur within this habitat type, but their presence has not been identified in the study area. Key Fauna Species Associated with the Habitat The only known high and medium biodiversity value species that are likely to associate with sandy beach habitats in the port study area are the five species of sea turtles that nest on sandy beaches. Species of native and migratory birds of lesser conservation interest may also be present at certain times of the year. Section 13.3.6 provides information on species in the port study area; a preliminary list of species known and likely to occur can be found in Annex 13A: Port Study Area Preliminary Marine Species List.

(1) Social and Environmental Baseline Studies (2012). (2) Social and Environmental Baseline Studies (2012).


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Sandy Beach – Medium Value Sandy beach habitats are considered to be of medium value as, although they are regionally widespread, they are locally rare and they may support high and medium value species as nesting or feeding areas. Criteria for high, medium and low value species are defined in Table 13.3 and the species are discussed further in Section 13.3.6 below.

13.3.4.7 Mangroves Habitat Description and Ecology Mangrove habitat is found along much of the coastline within the port study area and may occur tens of kilometres upstream along the rivers due to penetration of saline tidal waters. The non-uniformity of mangrove dominated shorelines creates an important habitat for migratory birds and other species, such as the West African manatee (1). Mangroves support species specifically adapted to the habitat type and communities that are highly specialised (2) and have a rich biodiversity. Mangroves also provide critical spawning and nursery areas for a variety of coastal and offshore species as well as helping to stabilise bottom sediments and protect shorelines from erosion (3). The mangroves and the channels draining them are relatively stable in the medium term, suggesting that a balance exists between sediment accretion and hydrological forces (4). Examples of mangrove habitats in the vicinity of the port study area are shown in Figure 13.4. Figure 13.4 Mangroves

Global and / or Regional Relevance Guinea’s mangrove population comprises a quarter of West Africa’s total mangrove wetland, giving it the third highest coverage of mangrove in the region, after Nigeria and Guinea-Bissau. This represents an estimated seven per cent of the total mangrove cover in Africa. Mangroves are therefore an important regional resource (5). Seven of the eight mangrove species found in West Africa are known to occur in

(1) US Aid (2007). Guinea Biodiversity and Tropical Forests 118/119 Assessment. Prepared by the Biodiversity Analysis and Technical Support Team. (2) Projet Simandou - Étude de caractérisation sociale et environnementale de base pour le port – Rapport provisoire. Dossier No: 604917. SNC Lavalin Environnement, Décembre 2008. (3) Mangrove.org (n.d.) Ecological Importance of Mangrove Habitat. Available at http://mangrove.org/video/Mangroves.pdf (4) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (5) UNEP (2007). Mangroves of Western and Central Africa. UNEP-Regional Seas Programme/UNEP-WCMC. Available at http://www.unep-wcmc.org/resources/publications/UNEP_WCMC_bio_series/26.htm


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Guinea, and four of these species have been identified in the port study area. Mangroves are found along the length of Guinea’s coastline. Most mangrove habitats in Ile Kaback are considered to be lower quality compared to less degraded areas elsewhere in the country. Threats and Extent of Degradation in Guinea Context Most mangrove habitats in the study area have been characterised as degraded due to high levels of human impact. The most serious threats to mangroves are uncontrolled exploitation as a result of rapid human population growth, and widespread conversion to rice fields (1). Other activities that threaten mangroves in Guinea are seasonal salt extraction, harvesting of trees for firewood, charcoal and building materials, shrimp farming and exploitation of crabs and oysters (2). These activities can cause direct habitat loss and indirect effects, by altering the local sediment regime and ecosystem dynamics (3). Conversion of mangroves to rice fields results in loss of tidal drainage, followed by hypersalinisation and acidification of the soil (4). The proposed port site has already been transformed by human activity as much of the coastline mangrove has been converted to rice fields, and large portions of Ile Kaback are heavily cultivated. Presence of Alien or Invasive Species During surveys in 2008, 40 specimens of an alien fish, the Mud sleeper (Butis koilomatodon), were collected from mangrove channels to the south of the port study area. This species is native to China, Australasia, Mozambique and Madagascar. It was first reported in Nigeria in the early 1980s, and more recently in mangroves in Guinea, and is believed to have been introduced to West Africa via ballast water. In surveys undertaken in 2011, however, only one individual was found. At present no ecological impacts are believed to be associated with the introduction of this species. Key Species Associated with the Habitat No high or medium biodiversity value mangrove species are known from the port study area, although the high value mangrove associated tree, Terminalia scutifera, is present but is discussed within Chapter 12: Terrestrial Biodiversity. The West African manatee (Trichechus senegalensis) is known to use mangrove habitat in Guinea and has been sighted within the port study area. This species is considered a medium biodiversity value species within the context of this SEIA. In addition, species of less conservation concern are also likely to be present within mangrove habitats in the port study area, such as fish including sharks, birds and invertebrates, although many marine fish and invertebrate species have not been assessed by the IUCN, and their conservation status is currently unknown. Section 13.3.6 provides information on species in the port study area; a preliminary list of species known and likely to occur can be found in Annex 13A: Port Study Area Preliminary Marine Species List. Other fauna reported as being present in mangroves in the port study area include monkeys, agoutis, ground squirrels and monitor lizards (5), however, these species are considered terrestrial species and are assessed in Chapter 12: Terrestrial Biodiversity.

(1) Kovacs J.M., de Santiago F.F., Bastien J. & Lafrance P. (2010). An Assessment of Mangroves in Guinea, West Africa, Using a Field and Remote Sensing Based Approach. Wetlands 30:773–782. (2) UNEP (2007). Mangroves of Western and Central Africa. UNEP-Regional Seas Programme/UNEP-WCMC. Available at http://www.unep-wcmc.org/resources/publications/UNEP_WCMC_bio_series/26.htm (3) FAO (2007). Les mangroves d’Afrique 1980-2005: Rapports Nationaux; Guinée. Forest Resources Assessment Programme, Working Paper 136, Rome, 2007. (4) Wolanski E. & Cassagne B. (2000). Salinity intrusion and rice farming in the mangrove-fringed Konkoure River delta, Guinea. Wetlands Ecology and Management 8: 29–36. (5) Social and Environmental Baseline Studies (2012)


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Mangroves – Medium Value Mangroves are considered to be medium value habitats as the species supported by them have specific adaptations to the habitat (1) and they support a high level of biodiversity. Criteria for high, medium and low value species are defined in Table 13.3 and the species are discussed further in Section 13.3.6 below.

13.3.5 Habitats Summary Table 13.5 presents a summary of the marine and littoral habitat types present in the port study area, their value rating, and the rationale for the assigned value as described in Section 13.3.4. Table 13.5 Summary of Habitat Value and Rationale for the Assigned Value

Habitat types Value Rationale

Offshore pelagic Low Not protected. Geographically widespread in the West African coastal region. Not considered to have special importance for any high or medium value species that may use this habitat.

Offshore benthic Low Not protected. Geographically widespread in the West African coastal region. Not considered to have special importance for any high or medium value species that may use this habitat.

Coastal and estuarine Medium Although this habitat is geographically widespread it supports species that have specific adaptations to the habitat and is used by a range of high and medium value species.

Intertidal mudflats and sandbanks

Medium Locally rare (although alternatives exist in the wider geographic region) and they support some species with specific adaptations to the habitat type, including some that are of conservation interest.

Rocky shore Not assessed Very little of this habitat is present in the study area, and it is not considered to have importance to any species of conservation interest, so it is not taken through to the impact assessment.

Sandy beach Medium Although this habitat is regionally widespread it is locally rare and may support high and medium value species as nesting or feeding areas.

Mangroves Medium Some species supported by mangroves have specific adaptations to the habitat and they support a high level of biodiversity, including medium and high value species.

13.3.6 Fauna Descriptions 13.3.6.1 Introduction This section provides baseline information on selected species from the following taxonomic groups that are known to occur, or potentially occur, in the biodiversity study area: mammals, birds, fish and reptiles. Each species is assigned a value based on the criteria defined in Section 13.2.5 and repeated in Table 13.6. As such species are grouped and discussed together by their biodiversity value, although specific species have been highlighted where appropriate. The following information on the groups of mammals, birds, fish and reptiles is presented: conservation status; global and regional range and distribution; habitat preference; known or expected locations within the biodiversity study area; and threats. (1) Projet Simandou - Étude de caractérisation sociale et environnementale de base pour le port – Rapport provisoire. Dossier No: 604917. SNC Lavalin Environnement, Décembre 2008.


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A preliminary list of all species (high, medium, low, and negligible value) known or considered to be potentially present in the biodiversity study area is presented in Annex 13A: Port Study Area Preliminary Marine Species List. Table 13.6 Species Value Criteria

Negligible No specific value or importance attached to the species.

Low Species not protected or listed; is widespread or abundant; and is not included in the criteria for high or moderate value.

Medium Species included on the IUCN red list of threatened species as Vulnerable (VU), Near Threatened (NT), or Data Deficient (DD) species (IUCN 2011). Species not included in the criteria for high value species.

High Species included on the IUCN red list of threatened species as Critically Endangered (CR) or Endangered (EN) species (IUCN 2011). Species and taxa that have a restricted range, defined as plants that are endemic to a site or found globally at fewer than 10 sites and fauna having a distribution range (or global breeding range for bird species) less than 50 000 km2.

13.3.6.2 Marine Mammals Cetaceans (Whales and Dolphins) In total 30 species of whales and dolphins may occur off the coast of Guinea, of which 12 have been confirmed present in Guinean waters from documented sightings, strandings or captures. There are 19 species that have not yet been recorded, but are expected to occur based on their known distribution in tropical waters and / or sightings in adjacent countries. Given the large ranges of many cetacean species, no species is expected to be dependent entirely on the marine habitats in Guinea. In addition, all species are expected to occur only occasionally due to their low recorded occurrence. As such, species are grouped and discussed together by their biodiversity value. A preliminary list of species expected to occur in the port study area together with their biodiversity value can be found in Annex 13A: Port Study Area Preliminary Marine Species List. The Sei whale (Balaenoptera borealis); Blue whale (Balaenoptera musculus); and Fin whale (Balaenoptera physalus) are considered as high biodiversity value cetacean species that may occur in the study area. The majority of the whales and dolphins that may occur in the study area are of medium biodiversity value and include those listed in Table 13.7. Table 13.7 Medium Value Whale and Dolphin Species

Latin Name Common Names IUCN Status

Balaenoptera edeni Bryde’s whale Data deficient

Globicephala macrorhynchus Short-finned pilot whale Data deficient

G. melas Long-finned pilot whale Data deficient

Kogia breviceps Pygmy sperm whale Data deficient

K. sima Dwarf sperm whale Data deficient

Mesoplodon densirostris Blanville’s beaked whale Data deficient

M. europaeus Gervais’s beaked whale Data deficient

Orcinus orca Killer whale Data deficient

Physeter macrocephalus Sperm whale Vulnerable

Pseudorca crassidens False killer whale Data deficient

Feresa attenuata Pygmy killer whale Data deficient

Delphinus capensis Long-beaked common dolphin Data deficient

Sousa teuszii Atlantic humpbacked dolphin Vulnerable


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Latin Name Common Names IUCN Status

Stenella clymene Clymene dolphin Data deficient

S. frontalis Atlantic spotted dolphin Data deficient

S. longirostris Spinner dolphin Data deficient

Several other species of whales and dolphins considered to be low biodiversity value may also occur in the port study area. The bottlenose dolphin (Tursiops truncatus) was the only marine mammal listed as Least Concern to be recorded from surveys, other than the manatee, Conservation status and distribution: Sei whales, Blue whales and Fin whales are listed as Endangered by IUCN; Sperm whales and Atlantic humpbacked dolphins are listed as Vulnerable and the remaining medium biodiversity value species are listed as data deficient. Sei, Blue, Fin and Sperm whales are widespread and generally globally distributed. Habitat preference: Cetacean species that may be found in the study area are whales and dolphins that are found predominantly in deeper offshore waters, although the smaller species are capable of moving into shallower coastal waters to feed. Locations within the study area: The cetacean species mentioned above are typically large cetaceans with extensive ranges that may on occasion migrate through offshore areas of the port study area. None of the species are considered to be endemic to the region and most are unlikely to occur frequently in inshore waters. Figure 13.5 presents dolphin sightings from dedicated surveys conducted for the Project; transect and fixed-point surveys were undertaken between June 2011 and February 2012, as well as opportunistic sightings also recorded. There were nine dolphin sightings during the survey period consisting mostly of solitary individuals and small groups. Dolphin sightings were spread out between June 2011 and February 2012. A total of eight dolphins sightings were opportunistic during general boat transit and one dolphin sighting occurred during dedicated transect surveys. The majority of dolphins observed were located between 100 to 300 m from the boat, but dolphins did approach the boat on occasion (exhibiting bow-riding behaviour) in December 2011 and again in February 2012.


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Figure 13.5 Dolphin Sightings (June 2011 – February 2012)

Threats: Most of the cetacean species are currently considered to be at low risk of human impact due to their offshore distribution, but may be sensitive to ship strikes and to vessel and noise disturbance. Entanglement in fishing gear is also a threat.

Cetaceans – High Value (Critically Endangered, Endangered or restricted range), Medium Value (Vulnerable, Near Threatened or Data Deficient), Low Value (Least Concern) Cetaceans that may occur in the port study area range in value depending on their IUCN status. All species are widespread and tend to occur offshore in low abundance. They are unlikely to be present frequently in coastal waters.

Particular mention of one dolphin species is warranted considering its preferred habitat in the inshore waters of West Africa.


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Atlantic humpbacked dolphin (Sousa teuszii) Conservation status and distribution: Atlantic humpbacked dolphins are listed as Vulnerable by IUCN, and are endemic to the sub-tropical Atlantic but not to Guinean waters. Habitat preference: Atlantic humpbacked dolphins are found in shallow and turbid coastal and inshore waters with soft sediment bottoms, near to sandbanks and mangrove lined estuaries. Locations within the study area: Atlantic humpbacked dolphins are thought likely to occur occasionally in the Morebaya River and coastal area, but sightings have principally been further from the coast (1). Threats: Atlantic humpbacked dolphins are threatened by a range of impacts including bycatch and poaching, loss of habitat and prey species, environmental contamination and vessel strikes.

Atlantic humpbacked dolphin – Medium Value The Atlantic humpbacked dolphin is a medium value species since it is listed as Vulnerable and is endemic to the sub-tropical Atlantic.

West African Manatee (Trichechus senegalensis) Conservation status and distribution: The West African manatee occurs along the coast of West Africa, including Guinea, and is listed as Vulnerable by the IUCN. Habitat preference: The West African manatee is found in coastal marine waters, brackish estuaries, and adjacent rivers. Manatees have a preference for low disturbance areas and shallow and calm waters, with access to freshwater. These manatees feed directly on mangrove foliage and they may be sensitive to changes in salinity and water flow. Manatees rest during the day in shallow water, often in channels or hidden in mangroves, feeding principally at night and travel in the late afternoon and at night. Locations within the study area: Anecdotal information from local villagers suggests that West African manatees are frequently observed in mangrove habitats surrounding rivers further south of the port study area (2) and feeding in mangrove channels, particularly during the rainy season (3). They have also been reported in the main channel of the Morebaya River, although further upstream than the port site. Studies by the Project indicate that manatees move around the mangrove systems depending on the season. During August and September (at the end of the rainy season) manatees are present in the lower river and surrounding areas, whereas in the dry season manatees move further upstream. There are three confirmed manatee sightings in the port study area, as shown in Figure 13.6. Two confirmed sightings were opportunistic (between November 2011 and February 2012) and one sighting occurred during a fixed point survey (October 2011). In addition two further possible sightings occurred during fixed point surveys in February 2012. It is therefore likely that manatees will be present seasonally but there does not appear to be a permanent presence at the immediate port site. Threats: Manatees are threatened by loss of mangrove habitat due to habitat alteration and degradation, and are also vulnerable to exploitation, entanglement in fishing gear and vessel strikes.

(1) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (2) SNCL, 2008 (3) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes.


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West African Manatee – Medium Value The West African manatee is a medium value species as it listed as Vulnerable on the IUCN Red List and it has a relatively limited distribution on the West African coast.

Figure 13.6 Confirmed and Possible Manatee Sightings

13.3.6.3 Birds Surveys undertaken in 2008 and 2011 in the port study area and other coastal areas nearby recorded 150 bird species (1). During the surveys, 47 species of migratory birds were recorded. Seasonally, the coast of Guinea is estimated to support half a million birds, most of which are migrant Palearctic waders. None of the species observed was in numbers over 1% of the total world population. Birds likely to be present in the habitats listed above include species of tern, cormorant, pelican, gull, skua, heron, ibis, wader, sandpiper and plover. Terrestrial bird species are considered in more detail in Chapter 12: Terrestrial Biodiversity. Bird species identified or likely to occur within the port study area are listed in Annex 13A: Port Study Area Preliminary Marine Species List. Conservation status and distribution: The majority of species identified within the port study area are common and widespread, however, the Eurasian curlew (Numenius arquata), which is Near Threatened, has been recorded at two locations on mudflats south of the port. The Eurasian curlew is migratory, with many birds breading in northern Europe and overwintering as far south as West Africa. Other migratory species (1) Social and Environmental Baseline Studies (2012).


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with less conservation concern are also likely to be present. The Timneh grey parrot (Psittacus timneh) and Yellow-casqued hornbill (Ceratogymna elata), which are both Near Threatened, may also be present within the mangrove habitat in the port study area, although they are considered terrestrial bird species and are considered in more detail in Chapter 12: Terrestrial Biodiversity. No marine high value bird species have been identified within the port study area or are expected to be present. Figure 13.7 Eurasian Curlew

Eurasian curlew (Numenius arquata)

Source: opencage.info

Habitat preference: The birds making use of the widest range of habitats found within the study area include species of heron, stork, ibis, wader, sandpiper, plover and the Eurasian curlew. These birds forage in intertidal zones, and can also be found in coastal and estuarine habitats and in mangroves. Coastal waters are used by gulls, terns and kingfishers for feeding, while gulls, terns, skuas, cormorants, ospreys and pelicans typically feed further offshore. Mangroves are used by most of the species listed above as either foraging, nesting or resting areas. Wading bird distribution is influenced by sediment quality, with different species showing preferences for areas with different grain sizes that support their targeted prey species (1). Locations within the study area: Gulls and skuas have been sighted offshore in the study area during surveys. Intertidal mudflats and sandbanks have been seen to support large populations of migratory wading birds. The Eurasian curlew is likely to be present on mudflats. Threats: The most serious threat to birds is the impact of loss and degradation on intertidal and mangrove habitats of importance to these species. Habitats may be degraded through land use change and development; altered sediment and hydrological regimes; contamination from pesticides and other chemicals; and exploitation of these habitats, such as timber harvesting from mangroves. Other key threats include: human disturbance, from foot-traffic and vehicles; direct mortality due to hunting; contamination of prey and accumulation of toxins within individuals; reductions in food availability due to overfishing and impacts on foraging habitats; and diseases such as avian influenza and avian botulism (2).

Eurasian Curlew – Medium Value. Other Birds – Low Value The Eurasian curlew is a medium value species as it is listed as Near Threatened on the IUCN Red List. Other marine species likely to be found in the port study area are of low value as they are not protected or listed and are widespread and / or abundant.

(1) Trolllet B. & Fouquet M. (2004). Wintering waders in coastal Guinea. Wader Study Group Bulletin 103: 6-62. (2) IUCN Red List of Threatened Species. Available at: http://www.iucnredlist.org/


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13.3.6.4 Reptiles Sea Turtles Five species of sea turtles are thought to be present in the port study area the Hawksbill turtle (Eretmochelys imbricata); Leatherback turtle (Dermochelys coriacea); Olive ridley sea turtle (Lepidochelys olivacea); Loggerhead sea turtle (Caretta caretta); and Green sea turtle (Chelonia mydas). The Hawksbill and Olive Ridley are shown in Figure 13.8. Figure 13.8 Hawksbill and Olive Ridley Turtles

Hawksbill Olive Ridley Source: Suzanne R Livingstone, The Biodiversity Consultancy

Conservation status and distribution: Hawksbill and Leatherback turtles are both Critically Endangered; Loggerhead and Green sea turtles are Endangered; and Olive Ridley sea turtles are Vulnerable according to the IUCN. All these species have global distributions in predominantly tropical waters and are highly mobile and migratory. The Atlantic coast of Africa is considered important for sea turtles. However, compared to its neighbouring countries in West Africa, Guinea has a low confirmed presence of nesting turtle species (1). Habitat preference: With some variations depending on the species, the life cycles of sea turtles often involve an early pelagic phase, followed by recruitment as juveniles to shallower coastal waters where foraging occurs. Adults are pelagic but tend to feed and breed in shallow inshore waters, and nesting occurs on sandy beaches, mainly in the tropics. Anecdotal information from fishermen in the wider region suggests that sea turtles move into the coastal zone from further offshore during the start of the rainy season (2). However, surveys conducted for the Project have only reported low numbers of sea turtles occurring infrequently in the port study area. Locations within the study area: Sandy beaches in the study area have potential to be used as nesting areas by all five species based on their distribution (3) (4), however, the beaches in the port study area are typically not the preferred beach type for nesting sea turtles. Local reports suggest that Olive Ridley, Hawksbill and Green turtles forage in the coastal waters and nest on beaches in the study area; however, surveys conducted for the Project suggest turtles occur only infrequently in very low numbers. The same surveys identified Hawksbill and Green turtles swimming in coastal waters, and it is suspected that the other three turtle species are also present at times. Leatherbacks and Loggerheads are thought to nest very rarely, but may be present in the coastal waters while moving along the coast. However, only one nest (thought to belong to a Hawksbill turtle) was recorded during surveys and no turtles were observed during in-water surveys. Overall, there is limited evidence of turtles in the area, and it is unlikely that they are present beyond a few occasional individuals. Figure 13.9 presents potential turtle beaches identified by participants in local meetings. However, there are no signs of significant nesting activity of any species on beaches within the port study area.

(1) Social and Environmental Baseline Studies (2012). (2) Le Fur J., Guilavogui A. & Teitelbaum A. (2011). Contribution of local fishermen to improving knowledge of the marine ecosystem and resources in the Republic of Guinea, West Africa. Can. J. Fish. Aquat. Sci. 68: 1454–1469. (3) Formia A., Tiwari M., Fretey J. & Billes A. (2003). Sea Turtle Conservation along the Atlantic Coast of Africa. Marine Turtle Newsletter 100:33-37. Available at http://www.seaturtle.org/mtn/archives/mtn100/mtn100p33.shtml (4) Social and Environmental Baseline Studies (2011).


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Figure 13.9 Potential Turtle Beaches

Threats: Targeted exploitation and bycatch through entanglement in fishing gear are the major threats to this species, but are mainly limited to turtles in coastal waters and on beaches. Many of the Green, Hawksbill and Olive Ridley sea turtles that occur in the study area are believed to be captured by locals and any eggs laid on local beaches are poached. Loss of habitat, human disturbance and marine pollution also represent a threat to these animals. The only serious threat to this group in offshore environments is from entanglement in fishing gear and vessel strikes.

Sea turtles – High Value, except the Olive Ridley turtle which is Medium Value All five species of sea turtle are listed as threatened (ie Vulnerable, Endangered or Critically Endangered), and are sensitive to exploitation and habitat degradation. The study area may occasionally be used for nesting, however, given that only small numbers of turtles have been reported infrequently the beaches nearby the port location are not considered to be globally or regionally important nesting sites for any turtle species.

Crocodiles Two species of crocodile have been confirmed present in the tributaries to the Morebaya River during surveys conducted for the Project: the Nile crocodile (Crocodylus niloticus); and the West African dwarf crocodile (Osteolaemus tetraspis). In addition a third crocodile may be present (slender-snouted crocodile, Mecistops cataphractus), however, it has not been confirmed in vicinity of the port, and given its rareness in West Africa and its preferred habitat type, it is unlikely to occur. Crocodiles are considered terrestrial animals and are therefore discussed within Chapter 12: Terrestrial Biodiversity. 13.3.6.5 Fish Pelagic Fish Approximately 570 marine fish species are known to occur in Guinea. Fish species found in the offshore pelagic environment have been assessed as having high, medium or low value based on their conservation status; however, elasmobranchs (sharks and rays) are the main ‘fish’ group that have been assessed under


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IUCN Red List criteria, therefore most of the species identified as having medium or high value are elasmobranchs. Other species that could be rated as high or medium value may be present but have not yet been assessed, and so their global threat status is unknown. Those species that are listed on the IUCN Red List that qualify as high or medium value species are presented below in Table 13.8.

Table 13.8 High and Medium Value Offshore Pelagic Fish Species Value Latin Name Common Names IUCN Status

High Value Sphyrna lewini Scalloped Hammerhead Endangered

Sphyrna mokarran Squat-Headed Hammerhead Endangered

Medium Value Alopias vulpinus Common Thresher Shark Vulnerable

Carcharhinus longimanus Oceanic Whitetip Shark Vulnerable

Carcharhinus falciformis Silky Shark Near Threatened

Carcharhinus signatus Night Shark Vulnerable

Prionace glauca Blue Shark Near Threatened

Heptranchias perlo Sharpnose Sevengill Shark Near Threatened

Isurus oxyrinchus Shortfin Mako Vulnerable

Isurus paucus Longfin Mako Vulnerable

Manta birostris Giant Manta Ray Near Threatened

Pseudocarcharias kamoharai Crocodile Shark Near Threatened

Rhincodon typus Whale Shark Vulnerable

Thunnus obesus Bigeye Tuna Vulnerable

Pelagic fish species of commercial importance include tuna (1), sardine and mackerel species, such as Albacore tuna (Thunnus alalunga), Round sardinella (Sardinella aurita), and West African Spanish mackerel (Scomberomorus tritor). These species are of lower conservation interest. Annex 13A: Port Study Area Preliminary Marine Species List provides a preliminary list of fish species likely to be present in the port study area. Conservation status and distribution: The two hammerhead species are both Endangered, and the remaining shark and ray species and Bigeye tuna are either Vulnerable or Near Threatened. All the high and medium value species listed are widespread and have large ranges. Habitat preference: Although these species are all pelagic, they may also be found further inshore and at a range of depths, from the surface to several hundred metres. Shallow inshore waters act as nursery zones for scalloped hammerheads, and may be similarly important for other shark species. Tuna, sardine and mackerel species may all be present seasonally in offshore waters during migrations. Locations within the study area: All these species have potential to occur within waters offshore Guinea, but are unlikely to be found further inshore in any great abundance. They tend to associate with the colder waters further offshore and to the north of the country far from the study area (2). Inshore waters may act as nursery areas for juveniles of a variety of species. Recent reports suggest Squat-headed hammerheads may now be absent from the wider region but they have been found in low numbers in trawls from the Conakry area. None of the species of conservation value have been recorded during surveys in the study area. Threats: Guinea’s fisheries have developed rapidly over the last few decades and now constitute a major threat to fish populations. Exploitation by artisanal fisheries is concentrated within shallower waters close to

(1) Atlas Infogéographique de la Guinée Maritime (2) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes.


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the shore (1), but fishing also occurs further offshore. The pelagic fishery tends to be very mobile, spending little time within Guinea’s economic zone as the waters do not support a great abundance of their target species (mackerel, sardines and sardinella) (2). However, large elasmobranchs, such as the shark species listed above, tend to be vulnerable to impacts leading to population declines (eg increased exploitation) due to their slow growth and late maturation. Shark species are threatened by targeted fisheries and from bycatch pressures. The fishery for Bigeye tuna is considered to be poorly regulated and there is concern that overcapacity in the Gulf of Guinea region is leading to overfishing.

Pelagic fish – High Value (Critically Endangered, Endangered or restricted range); Medium Value (Vulnerable, Near Threatened or Data Deficient); and Low Value (Least Concern) Pelagic fish that may occur in the port study area range in value depending on the IUCN status. All species are widespread and highly mobile.

Coastal Shark and Ray Species Coastal species of shark and ray likely to be present in estuarine, coastal and / or offshore waters and are assessed as having high or medium value due to their conservation status are listed below in Table 13.9. Low value species may also be present. Annex 13A: Port Study Area Preliminary Marine Species List provides a preliminary list of fish species likely to be present in the port study area.

Table 13.9 High and Medium Value Coastal Shark and Ray Species Value Latin Name Common Names IUCN Status

High Value Squatina aculeata Sawback Angel Shark Critically Endangered

Squatina oculata Smoothback Angel Shark Critically Endangered

Rostroraja alba Bottlenose Skate Endangered

Pristis perrotteti Largetooth Sawfish Critically Endangered

Pristis pristis Common Sawfish Critically Endangered

Pristis pectinata Wide Sawfish Critically Endangered

Dasyatis margarita Daisy Stingray Endangered

Rhinobatos cemiculus Blackchin Guitarfish Endangered

Rhinobatos rhinobatos Common Guitarfish Endangered

Rhynchobatus luebberti Lubbert’s Guitarfish Endangered

Medium Value Rhinobatos albomaculatus White-spotted Guitarfish Vulnerable

Rhinobatos irvinei Spineback Guitarfish Vulnerable

Urogymnus asperrimus Porcupine Ray Vulnerable

Gymnura altavela Spiny Butterfly Ray Vulnerable

Rhinoptera bonasus Cownose Ray Near Threatened

Aetobatus narinari Spotted Eagle Ray Near Threatened

Raja clavata Thornback Skate Near Threatened

Mustelus mustelus Common Smoothhound Vulnerable

Carcharhinus leucas Bull Shark Near Threatened

Galeocerdo cuvier Tiger Shark Near Threatened

Leptocharias smithii Barbeled Houndshark Near Threatened

(1) Lobry J., Gascuel D. & Domain F. (2003). La biodiversité spécifique des ressources démersales du plateau continental guinéen : utilisation d’indices classiques pour un diagnostic sur l’évolution de l’écosystème. Aquatic Living Resources 16: 59–68. (2) Lesnoff M., Morize É. & Traore S. (1995). La pêcherie industrielle en Guinée: état et bilan des données disponibles. In « La pêche Côtière en Guinée : Ressources et exploitation ». CNSHB/IRD, p. 175-198.


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Value Latin Name Common Names IUCN Status

Carcharias taurus Sand Tiger Shark Vulnerable

Sphyrna zygaena Smooth Hammerhead Vulnerable

Oxynotus centrina Angular Rough Shark Vulnerable

Rhinoptera marginata Lusitanian Cownose Ray Near Threatened

Conservation status and distribution: All the angel shark and sawfish species are Critically Endangered, and the guitarfish species, the Daisy stingray and the Bottlenose skate are Endangered according to the IUCN and are therefore considered of high conservation value. All the medium value species listed above are either Vulnerable or Near Threatened. Most of the species are distributed throughout the continental shelf of the eastern Atlantic and are native to Guinea, while most of the shark species have a more widespread or even global distribution. Some previously widespread species (Wide sawfish and Spiny butterfly ray) now have much more patchy distributions (1). The population of common sawfish is severely depleted in Africa and the Largetooth sawfish may already be extinct in Guinea (2). Habitat preference: Most of these species are predominantly associated with the seabed, with varying preferences as to the specific substrate and depth. Many are tolerant of a wide range of salinities and can be found in marine, estuarine and sometimes freshwater environments where they are mainly predators of benthic organisms and small fish. Juveniles are often found in shallower waters, and certain areas may provide nursery habitats for particular species, for example shallow sandy substrates for the Smooth hammerhead. Some species, such as the Angular rough shark may inhabit deeper seabed areas, at 60 m and below. Guitarfish species are known to occasionally bury themselves in bed sediments. The Blackchin guitarfish may aggregate during September and October off sandy areas and mangroves to breed. The shark species listed above are less strongly associated with the seabed, and are likely to be found in the water column. Most of these species are fairly mobile within shallow coastal waters. Both the bull shark and the lemon shark are commonly found near the mouths of rivers and may move into estuaries to breed. Locations within the study area: All species listed above may occur within the study area. The Smoothback angel shark is thought to form aggregations off the West African coast during December. However, only four species of conservation interest have been identified during surveys in support of the project: Blackchin guitarfish; Daisy stingray, Lusitanian cownose ray; and a juvenile Bullshark. The Blackchin guitarfish and Daisy stingray were were caught in 2008 and 2012 but not found during surveys in 2011 (3). The Lusitanian cownose ray and a juvenile Bullshark were only recorded during the 2012 survey. During the 2012 survey the Blackchin guitarfish was identified in fishing zones 7, 9, 11 and 16, while the Daisy stingray was identified in fishing zones 1, 4, 7, 9, 10, 13 and 16. The Lusitanian cownose ray was identified only in fishing zone 16 and a juvenile Bullshark was identified in fishing zone 6. The highest number of species (including those not of conservation concern) was recorded in fishing zones 7, 9 and 13. Figure 13.10 presents the locations of the fishing zones as defined by the 2012 survey.

(1) IUCN (2011). IUCN Red List of Threatened Species. Version 2011.2. Available at www.iucnredlist.org - last accessed 08 June

2012. (2) IUCN (2011). IUCN Red List of Threatened Species. Version 2011.2. Available at www.iucnredlist.org - last accessed 08 June

2012. (3) Social and Environmental Baseline Studies (2011).


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Figure 13.10 2012 Fishing Zones and Trap Net Sites

Threats: Guinea’s fisheries have developed rapidly over the last few decades and now constitute a major threat to fish populations. Exploitation of demersal fish in coastal areas, which include many of the skate and ray species listed above, is particularly intense (1) (2). The industrialised fishery in particular is dominated by trawlers targeting demersal fish (3). All species listed above are vulnerable to human impacts leading to population declines (eg increased exploitation) due to the slow life history characteristics of larger elasmobranchs. They experience serious threats from targeted fisheries, and those species that are not commercially fished are often taken as bycatch. Many of these species are especially susceptible to bycatch in trawls, due to their close association with the seabed. Some species, such as the Largetooth and Wide sawfishes, Porcupine rays and guitarfishes may also be threatened by habitat degradation, such as loss of mangroves.

(1) Lobry J., Gascuel D. & Domain F. (2003). La biodiversité spécifique des ressources démersales du plateau continental guinéen : utilisation d’indices classiques pour un diagnostic sur l’évolution de l’écosystème. Aquatic Living Resources 16: 59–68. (2) Guinea Biodiversity and Tropical Forests 118/119 Assessment - United States Agency for International Development, December 2007. (3) Lesnoff M., Morize É. & Traore S. (1995). La pêcherie industrielle en Guinée: état et bilan des données disponibles. In « La pêche Côtière en Guinée : Ressources et exploitation ». CNSHB/IRD, p. 175-198.


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Coastal sharks and rays – High Value (Critically Endangered, Endangered or restricted range); Medium Value (Vulnerable, Near Threatened or Data Deficient); and Low Value (Least Concern) Coastal sharks and rays that may occur in the port study area range in value depending on the IUCN status. Most species have fairly broad ranges within the eastern Atlantic, although several species have increasingly patchy distributions.

Other Coastal and Estuarine Fish Species A diverse fish community is associated with Guinea’s coastal waters, with species from predominantly three groupings. The commercially important sciaenid fish community (drums and croakers) constitutes the majority of biomass, with clupeid fish (herring-like fish) also very abundant (1), while the sparid community (sea breams) is both less commercially valuable and abundant. The most abundant species identified during surveys in 2011 (numbering over 100 individuals caught) include: Bobo croaker (Pseudotolithus elongatus); West African ilisha (Ilisha africana); Royal threadfin (Pentanemus quinquarius); Bonga shad (Ethmalosa fimbriata); Bigeye grunt (Brachydeuterus auritus); and Prickly puffer (Ephippion guttifer). These fish and similar species are for the most part targeted by local artisanal fisheries, along with other groups such as tonguefish (Cynoglossidae spp.) and catfish (Siluriformes). Annex 13A: Port Study Area Preliminary Marine Species List provides a preliminary list of fish species likely to be present in the port study area. Fish species which may be present in the study area have been assigned a high, medium or low value due to their IUCN status. High and medium value species include: Goliath grouper (Epinephelus itajara) and Dusky grouper (Epinephelus marginatus); and Blunthead puffer (Sphoeroides pachygaster). Conservation status and distribution: The Goliath grouper is Critically Endangered, the Dusky grouper is Endangered and the Blunthead puffer is Vulnerable. No other species of conservation value or species with restricted ranges are expected to be present in the study area. A large part of the fish communities in West African coastal waters and estuaries consists of a ubiquitous group of species found throughout this region (2). Habitat preference: Seventy percent of the area’s fish biomass is found in waters less than 20 m deep, and particularly in the vicinity of major estuaries (3). The sciaenid fish community is associated with rich muddy and muddy-sand bottoms in warm, shallow, hyposaline waters (4) and with areas of fringing mangrove (5). Species of the sciaenid community and surface dwelling clupeids migrate between subtidal mudflats and estuaries with the spread and retreat of nutrient rich estuarine waters. The less valuable sparid community is more widely dispersed and less mobile, preferring colder and more saline water near the bed (6). The community shows little seasonal and geographic variation, mainly comprising species tolerant of a range of environmental conditions. Over 60% of species were observed in the area during both seasons, with roughly equal numbers of species only observed during either the rainy or the dry season. Slightly more estuarine species with freshwater affinities were observed during the dry season (7). Anecdotal information from fishermen in the wider region suggests that fish tend to migrate further out to sea during March and April, in conjunction with warmer water temperatures. It was also suggested that at the start of the rainy season pelagic fish move into the coastal area, forming shoals, and in December through until February many fish

(1) Baran E. (2000). Biodiversity of Estuarine Fish Faunas in West Africa. Naga, The ICLARM Quarterly Vol. 23, No. 4, p. 4-9. (2) Baran E. (2000). Biodiversity of Estuarine Fish Faunas in West Africa. Naga, The ICLARM Quarterly Vol. 23, No. 4, p. 4-9. (3) Atlas Infogéographique de la Guinée Maritime (4) Social and Environmental Baseline Studies (2011). (5) Projet Simandou - Étude de caractérisation sociale et environnementale de base pour le port – Rapport provisoire. Dossier No: 604917. SNC Lavalin Environnement, Décembre 2008. (6) Atlas Infogéographique de la Guinée Maritime. (7) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes.


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species move closer to the bed (1). Both grouper species inhabit reefs, but the Goliath grouper is also found in mangrove and estuarine habitats. Juvenile Goliath grouper are strongly associated with mangrove habitats. The Blunthead puffer inhabits sandy, muddy and rocky bottoms. Pelagic species are generally relatively less abundant than demersal species in the coastal and estuarine areas. Fish species that are purely estuarine or have freshwater affinities tend to be associated with the mangroves, which have a more clearly defined community. The shelf edge community is predominantly associated with muddy substrates on the deeper seabed close to the continental shelf edge. Other communities are associated with more specific benthic habitats, such as rocky substrate and the continental slope (2). Locations within the study area: None of the species of conservation concern listed above have been recorded in the study area, however, over the lifetime of the Project they may occur, and in addition many low value species are present. The coastal and estuarine fish community is dominated by species with strong marine affinities (3) while species with freshwater affinities are largely absent (4) (5). This assemblage, is typical of an inverse estuary where there is little freshwater influence and therefore no barrier to marine species entering (6). Characteristic fish for this community include West African ilisha and some species of threadfin. Separate fish communities are associated with mangrove channels (more estuarine species and those with freshwater affinities) and the shelf edge (marine, demersal species). Species associated with mangrove channels include Bagrid catfish (Chrysichthys nigrodigitatus) and Porogobius schlegelii (7). The shelf edge community constitutes a significant biomass but is not very species rich and largely not commercially important (8). The abundant Bobo croaker and West African ilisha were found to be the most widespread fish during fish surveys to the south of the port site (9). Threats: Guinea’s waters have been subject to heavy exploitation over the last three decades by both industrialised and artisanal fisheries. Prior to the early 1980s both fishing sectors were not very active but they have experienced rapid growth (10). It has been estimated that the fish population halved between 1986 and 1992 and a more recent report has estimated that the current population is one fifth of its pre-exploitation size. Fishing efforts of both artisanal and industrial fisheries have focused on shallow coastal waters, and demersal fish species have been particularly impacted (11) (12). The most common form of artisanal fishing in the region, using boats and gill nets, targets a wide range of species, including demersal and pelagic fish. Demersal fishing from vessels closer inshore predominantly target sciaenids, such as croakers and grunts, as well as catfish, rays and sharks. Pelagic fishing with gill nets also occurs, targeting mainly Bonga shad (13). This chapter considers impacts on the biodiversity value of fish species. Fisheries

(1) Le Fur J., Guilavogui A. & Teitelbaum A. (2011). Contribution of local fishermen to improving knowledge of the marine ecosystem and resources in the Republic of Guinea, West Africa. Can. J. Fish. Aquat. Sci. 68: 1454–1469. (2) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (3) Social and Environmental Baseline Studies (2011). (4) Social and Environmental Baseline Studies (2011). (5) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (6) Baran E. (2000). Biodiversity of Estuarine Fish Faunas in West Africa. Naga, The ICLARM Quarterly Vol. 23, No. 4, p. 4-9. (7) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (8) Social and Environmental Baseline Studies (2011). (9) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (10) Chavance P., Damiano A. & Diallo A. (1995). La pêche artisanale: histoire, structure, fonctionnement et dynamique: Caractéristiques des lieux de débarquements et physionomie de la pêche. In « La pêche Côtière en Guinée : Ressources et exploitation ». CNSHB/IRD, p. 313-326. (11) Lobry J., Gascuel D. & Domain F. (2003). La biodiversité spécifique des ressources démersales du plateau continental guinéen : utilisation d’indices classiques pour un diagnostic sur l’évolution de l’écosystème. Aquatic Living Resources 16: 59–68 (12) Guinea Biodiversity and Tropical Forests 118/119 Assessment - United States Agency for International Development, December 2007. (13) Chavance P., Damiano A. & Diallo A. (1995). La pêche artisanale: histoire, structure, fonctionnement et dynamique: Caractéristiques des lieux de débarquements et physionomie de la pêche. In « La pêche Côtière en Guinée : Ressources et exploitation ». CNSHB/IRD, p. 313-326.


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are discussed in further detail in the socio-economic chapters (1). In addition, loss of mangroves contributes to reduced fish stocks, as these areas are important for breeding and for juvenile fish (2).

Coastal and estuarine fish – High Value (Critically Endangered, Endangered or restricted range); Medium Value (Vulnerable, Near Threatened or Data Deficient); and Low Value (Least Concern) Coastal and estuarine fish that may occur in the port study area range in value depending on the IUCN status. Most species are relatively widespread, with tolerance to a broad range of environmental conditions.

13.3.6.6 Invertebrates The coastal region (ie areas with less than 20 m water depth) supports a diverse community of benthic invertebrates, dominated by annelids, molluscs and crustaceans (3). Surveys conducted for the Project have identified over 600 species of invertebrates. The most abundant and commonly found groups include some species of echinoderm and mollusc, and nemertid and polychaete worms. Notable species include the abundant and ecologically important Fiddler crab (Uca tangeri), and some commercially important species of shrimp and crab, such as Candied shrimp (Farfantepenaeus notialis). A solitary cup coral species (ie not reef forming), Caryophyllia sp. has been recorded during the benthic survey to the south of the port location. This coral is not protected. Conservation status and distribution: No high or medium value species have been identified during surveys in the area, although some species listed as nationally endangered were present in 2008 samples. These include Candied shrimp, Guinean shrimp (Holthuispenaeopsis atlantica); Smooth swimcrab (Portunus validus); and some species of squid and cuttlefish. None of these species were caught during the 2011 sampling period. No endemic or restricted range species have been identified (4). Habitat preference: Benthic and epibenthic invertebrate species richness, diversity and abundance is higher in the coastal zone compared to estuarine waters and mangroves (5). The Fiddler crab is found in high abundance in intertidal areas and mangroves, and is an important food source for many birds. Both Fiddler crabs and the Mangrove oyster (Crassostrea gasar) are strongly associated with red riverine mangroves bordering channels, which experience the most tidal action. Commercially important crab and shrimp species are found in both the pelagic and benthic offshore zones. The coral species are found attached to rocky substrates. Locations within the study area: The density and diversity of benthic organisms in general increased from the estuary into coastal and marine areas. Higher densities of invertebrates, and especially molluscs, were associated with the finer sediments to the south of the port location. Spatial variation in benthic communities was evident with five distinct benthic assemblages identified. Assemblages were primarily influenced by depth of water and also by substrate. The distributions of these assemblages were also closely related to differences in habitat and are characterised as follows (6): the largest benthic assemblage is predominantly located off the Forécariah piedmont, an area

characterised by finer (sand-mud) substrates, and in deeper waters;

(1) See Chapter 16: Socio-Economic and Community Baseline, Chapter 17: National Economy, Chapter 18: Employment and Economic Development, Chapter 19: In-Migration and Chapter 20: Land Use and Livelihoods. The contribution of biodiversity attributes to ecosystems services is described in Chapter 24: Ecosystem Services. (2) Guinea Biodiversity and Tropical Forests 118/119 Assessment - United States Agency for International Development, December 2007. (3) Social and Environmental Baseline Studies (2012). (4) Social and Environmental Baseline Studies (2012). (5) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes. (6) Social and Environmental Baseline Studies (2012).


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the second assemblage is mostly located off the mouth of Melacorée and Tana Rivers in the deep

channel characterised by coarser sand substrates; the third assemblage is located on the tidal flats where organisms may be affected by the rise and fall of

the sea, and salinity fluctuations;

the fourth assemblage is located at the mouth of the Forécariah and Morebaya Rivers where sediment deposition from river discharges is dominant; and

the last assemblage is mostly located off Kaback in deeper waters. Threats: Invertebrates are sensitive to loss of or changes to their habitat (eg sediment type and water quality) and smothering. Population declines in invertebrates may occur where the species in question already has a limited distribution or relies on a patchily available habitat (1). Some groups of invertebrates are subject to exploitation as either targeted or bycatch. Estuarine shrimp species are targeted both by motorised vessels using gill nets, and by hand held nets used from the shore, in mangroves and in rice fields (2). Squid and cuttlefish are targeted by the industrial fishery (3). The coral species described above is thought to be quite resilient to changes in suspended sediment concentration, but sensitive to smothering from sediment deposition.

Invertebrates – Low Value No high or medium value species or species with restricted distributions have been identified.

13.3.6.7 Flora Mangrove Mangroves are plants that can cope with the high concentrations of salt and regular inundation of their root systems by incoming tides (4). The distribution of mangrove species and communities is determined by frequency and extent of submersion, salinity and sediment regime (5). Seven mangrove and mangrove associated species are known to occur in Guinea, however, only four species of mangrove are being considered for the Kaback region. These species can be divided into six initial classes (as illustrated in Figure 13.11), however, only four classes have been identified within the port study area: tall red, medium red, dwarf red and black mangroves. Both the tall and medium red mangroves are considered to be riverine mangroves and are located along the edges of the tidal creeks and along the main estuaries where ideal conditions of low water salinities and daily tidal flushing occur. In contrast, the dwarf red mangrove and the black mangrove are considered either fringe or basin mangroves. For the Kaback region, the dwarf red mangrove form a transition zone between the medium red mangrove and the much higher elevated and further inland black mangrove. The black mangrove is ideally suited to drier conditions and higher salinities and thus forms the transition zone between the dwarf red mangrove and saltpans or terrestrial vegetation. Mangroves in the port study area adhere strongly to this pattern of zonation, which is typical of West Africa, forming mainly homogeneous stands. Each of the four classes tends to be dominated by a single mangrove species, from which the classes take their names, but other species may be present: black mangrove (Avicennia germinans);

(1) Roberts C.M. & Hawkins J.P. (1999). Extinction risk in the sea. Trends in Ecology and Evolution 14(6): 241–246. (2) Chavance P., Damiano A. & Diallo A. (1995). La pêche artisanale: histoire, structure, fonctionnement et dynamique: Caractéristiques des lieux de débarquements et physionomie de la pêche. In « La pêche Côtière en Guinée : Ressources et exploitation ». CNSHB/IRD, p. 313-326. (3) Lesnoff M., Morize É. & Traore S. (1995). La pêcherie industrielle en Guinée: état et bilan des données disponibles. In « La pêche Côtière en Guinée : Ressources et exploitation ». CNSHB/IRD, p. 175-198. (4) UNEP (2007). Mangroves of Western and Central Africa. UNEP-Regional Seas Programme/UNEP-WCMC. (5) Atlas Infogéographique de la Guinée Maritime.


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tall red mangrove (Rhizophora racemosa); medium red mangrove (Rhizophora racemosa); and dwarf red mangrove (Rhizophora mangle and Rhizophora harisonii). In addition the Golden leather fern (Acrostichum aureum) and a species of tree associated with mangroves (Terminalia scutifera), have also been identified in the port study area. However, Terminalia scutifera is described in Chapter 12: Terrestrial Biodiversity. Figure 13.11 Riverine Mangrove Assemblages

Source: SNCL, 2008.

Conservation status and distribution: Where IUCN status has been assigned to these mangrove species, they are considered to be of Least Concern and their population trends are listed as decreasing. No status has been assigned for Rhizophora harrisonii. All of the mangrove species are widespread in the neotropics and in West Africa. Golden leather fern and red mangrove are considered common across parts of their range while Rhizophora racemosa has a more patchy distribution. Habitat preference: The habitat distribution and preference for the mangrove species above is described in Section 13.3.4. In summary the tall and medium red mangrove is generally located along the edges of the tidal creeks and along the main estuaries where there is low salinities and daily tidal flushing. The dwarf red mangrove form a transition zone between the medium red mangrove and the much higher elevated and further inland black mangrove, which is suited to drier conditions and higher salinities. Locations within the study area: On Ile Kaback mangrove is concentrated along the estuaries, river channels and tidal creeks (1). Of the four mangrove classes mapped the black mangrove dominates followed by dwarf red mangrove then the tall and medium red mangrove together.

(1) Projet Simandou — État de référence du milieu aquatique – Site des installations portuaires. Rapport présenté à SNC-Lavalin - Environnement par Environnement Illimité inc. 242 pages et 10 annexes.


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Threats: Threats to mangroves are described under mangroves as habitats. These include land use change and destruction for timber.

Mangrove trees – Medium Value No high value species identified. Most are relatively widespread, although currently in decline due to development pressures such as farming, and mangroves create important habitats for a large range of marine and terrestrial species.

Other Marine Plants Baseline studies have not identified any seagrass or macroalgae in the port study area. The absence of marine plants probably reflects the highly turbid and moderate energy nature of the inshore waters. Marine benthic plants require sufficient water clarity to enable photosynthesis. Seagrasses grow in relatively clear shallow water in low energy environments and macroalgae typically grow on hard substrates in low turbidity environments. 13.3.6.8 Summary of Information on Fauna The discussion of impacts below refers to groups of species based on their value, although specific species have been highlighted where appropriate (as described in Section 13.3.6). Table 13.10 presents a summary of the key high and medium value fauna species described above that are known or expected to occur in the marine and littoral habitats within the port study area, and which may be affected by the Project. The species presented in Table 13.10 have been selected from Annex 13A: Port Study Area Preliminary Marine Species List based on their habitat preference (marine) and their IUCN category (Critically Endangered, Endangered, Vulnerable and Near Threatened).


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Table 13.10 Summary of Value, Rationale for the Assigned Value and Habitat in which the Species is Found

Scientific Name Common Name

Species Rationale SEIA Value Rating

Recorded / Likely Present

Habitats in which Species is Found IUCN Status

Restricted-Range

Marine Mammals

Balaenoptera borealis Sei Whale EN No High Likely Present Mainly found in the offshore pelagic habitat but may occur rarely in the coastal region.

Balaenoptera musculus

Blue Whale EN No High Likely Present Mainly found in the offshore pelagic habitat but may occur rarely in the coastal region.

Balaenoptera physalus Fin Whale EN No High Likely Present Mainly found in the offshore pelagic habitat but may occur rarely in the coastal region.

Physeter macrocephalus

Sperm Whale VU No Medium Likely Present Mainly found in the offshore pelagic habitat but may occur rarely in the coastal region.

Sousa teuszii Atlantic Humpbacked Dolphin

VU No Medium Likely Present Mainly found in the offshore pelagic habitat but may occur in the coastal region and in estuaries.

Trichechus senegalensis

West African Manatee VU No Medium Likely Present Mainly found in mangrove and estuarine habitats.

Birds

Numenius arquata Eurasian Curlew NT No Medium Recorded Mainly found in intertidal habitats (eg mudflats) but can also be found in coastal and estuarine habitats and in mangroves.

Marine and Littoral Reptiles

Caretta caretta Loggerhead Turtle EN No High Likely Present Mainly found in the offshore pelagic habitat but may occur occasionally in the coastal region or on sandy beaches.

Chelonia mydas Green Turtle EN No High Recorded Mainly found in the offshore pelagic habitat but may occur occasionally in the coastal region or on sandy beaches.

Eretmochelys imbricata

Hawksbill Turtle CR No High Recorded Mainly found in the offshore pelagic habitat but may occur occasionally in the coastal region or on sandy beaches.

Lepidochelys olivacea Olive ridley Turtle VU No Medium Recorded Mainly found in the offshore pelagic habitat but may occur occasionally in the coastal region or on sandy beaches.


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Scientific Name Common Name

Species Rationale SEIA Value Rating

Recorded / Likely Present

Habitats in which Species is Found IUCN Status

Restricted-Range

Dermochelys coriacea Leatherback Turtle CR No High Likely Present Mainly found in the offshore pelagic habitat but may occur occasionally in the coastal region or on sandy beaches.

Fish

Dasyatis margarita Daisy Stingray EN No High Recorded Can be found in marine and estuarine habitats.

Epinephelus aeneus White Grouper NT No Medium Recorded Can be found in estuarine, coastal and/or offshore waters.

Pristis pectinata Wide Sawfish CR No High Likely Present Can be found in estuarine, coastal and/or offshore waters.

Pristis perrotteti Largetooth Sawfish CR No High Likely Present Can be found in estuarine, coastal and / or offshore waters.

Rhinobatos albomaculatus

White-spotted Guitarfish VU No High Likely Present Can be found in inshore and coastal waters.

Rhinobatos cemiculus Blackchin Guitarfish EN No High Recorded Can be found in inshore and coastal waters.

Rhinobatos irvinei Spineback Guitarfish VU No Medium Likely Present Can be found in coastal waters.

Rhinobatos rhinobatos Common Guitarfish EN No High Likely Present Can be found in coastal and/or offshore waters.

Rhinoptera bonasus Cownose Ray NT No Medium Recorded Can be found in estuarine and coastal waters.

Rhynchobatus luebberti

African Wedgefish EN No High Likely Present Can be found in inshore and coastal habitats.


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13.4 Impact Assessment 13.4.1 Introduction This section presents the results of the assessment of the Simandou Port’s impacts on marine biodiversity as described in Section 13.3. Impacts are classified as direct or indirect as shown below and as described in Table 13.11 and Table 13.12 and assessed against the criteria of value and magnitude as described in Table 13.2 (for habitats) and Table 13.3 (for fauna and flora). Direct impacts are classified as: loss of habitat through land occupied for construction of the port (including the MOF, dredged shipping

channels and dredged material disposal areas); direct injury or mortality to species from vessel collisions and from equipment; noise and vibration (underwater and airborne); altered water quality; altered sediment quality; and light disturbance. Indirect impacts include secondary impacts due to issues such as: loss of habitat outside the port, MOF and shipping channels footprint; introduction of invasive alien species; induced human access (increased pressures on natural resources); and non-routine events such as spills. The evaluation of impact significance is carried out through consideration of the assigned value and predicted magnitude of each direct and indirect impact type. Many of the impacts will begin during the port construction phase and continue throughout the port operation. Where impacts are expected to differ between construction and operational phases of the project, their significance is considered separately; otherwise impacts from construction and operation are assessed together. Where relevant, the direct and indirect impacts listed above are assessed for each habitat type and then for groups of taxa that may be impacted. For the purposes of the assessment mangrove are considered to be habitats. Table 13.11 Summary of Direct Impacts Assessed

Habitat loss Occupation and removal of seabed and littoral habitats for the port, access channel and dredged material disposal leading to: loss of seabed habitats that support fish and invertebrate species; and loss of littoral habitats, including intertidal mudflats, sandbanks and mangroves, which have importance for a wide range of species as feeding, resting, breeding and nursery areas.

Mortality and injury of wildlife

Disturbance of wildlife in the vicinity of the port and access channel. Direct mortality and injury of individuals from collision with vessels or entrainment, including dredgers.

Noise Behavioural and physical responses of wildlife to port-related noise.

Altered water quality

Response of marine species to changes in water quality resulting from dredging and port activities.

Altered sediment quality

Response of marine species to changes in sediment quality resulting from dredging and port activities.

Artificial light Behavioural responses of wildlife to Project-related lighting.


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Table 13.12 Summary of Indirect Impacts Assessed

Indirect habitat loss Alterations to the hydrodynamic and sediment regime may result in the indirect loss of habitats through erosion deposition of habitats. Loss of hydraulic connectivity within mangrove systems may cause further loss of mangroves. Impacts on habitats may result in changes in the abundance and distribution of the species they support.

Invasive alien species

Introduction of invasive alien species that out-compete native species may lead to changes in species composition and degradation of habitat and a potential change in community composition.

Induced access (increased pressures on natural resources)

Increased human access may result in additional mangrove habitat loss from conversion to cultivated land. Increased human presence will also increase pressures on existing fisheries.

Waste Introduction of litter and waste into the marine, estuarine and littoral environment has the potential to harm marine fauna and avifauna through ingestion or trapping or entanglement in litter. Discarded food wastes will also attract vermin and gregarious birds to the local area, potentially displacing local species.

Non-Routine Events - Spills

Shipping-related accidental spillages and spills at the port during fuel transfer may release pollutants to the marine and littoral environment, which can impact on water quality and littoral habitats and affect the marine, estuarine and littoral ecosystem.

13.4.2 Direct Impacts: Loss of Habitat 13.4.2.1 Overview Habitat will be lost where the river bed and seabed will be dredged, where sediments will be disposed offshore and where access is required in the interface between sea/ river and land. The impacts of direct habitat loss are assessed together for construction and operation as dredging, including maintenance dredging, and associated dredged material disposal will be performed regularly throughout the project lifetime. Maintenance dredging typically has fewer direct impacts to benthic communities since the dredging footprint has been dredged previously and, depending on the frequency of dredging, the marine communities within the footprint will be less well established and not representative of the ‘natural’ communities in nearby un-dredged areas. Current estimates for the port project are for the need to dredge the shipping access channels every year which will prevent the benthic communities from becoming well established within the dredging footprint between successive dredging cycles. This assessment also considers the marine and littoral land permanently occupied by the MOF in order to cumulatively assess impacts that result from the port Project and the on-going operation of the MOF. The total dredged area of the approach channel and port is estimated as 19 km2, which is the equivalent of 160 Mm3 of dredged material during construction, of which an estimated 14 Mm3 will already have been dredged during construction of the MOF. Maintenance dredging is currently estimated at a further 20 - 50 Mm3 per year. Part of the design of the dredged area is to minimise the dredging (both in volume and area). The dredged material disposal area (as shown in Figure 13.1) is approximately 15 km2, and is planned to be used for the disposal of dredged sediment from both the port construction and port operation phases. Further disposal sites will be identified during the operational phase as required. Dredged material disposal will be continuous throughout the construction phase but intermittent during the operation phase, and the location where the dredging vessels release their load within the designated disposal area will vary throughout each dredging programme. Once released, the sediment will drop to the sea floor and smother the seabed. The descending plume will spread in a lateral direction. Construction dredging is estimated to take place over a period of 36 months, using up to seven dredgers at any one time. In total, 8 ha of mangrove will have been cleared under the MOF footprint. Construction of the export wharf will not require further mangrove clearance alongside the wharf.


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13.4.2.2 Loss of Habitat Offshore Benthic Habitat Dredging of the offshore parts of the access channel and the disposal of dredged material will result in a direct loss of offshore benthic habitat during both construction and operation. With both dredging and dredged material disposal, there will be total loss of seabed habitat within the footprint as the seabed is removed in the dredged areas and the seabed is smothered during disposal of the dredged material at the disposal area. Maintenance dredging will occur regularly throughout the lifetime of the project preventing the benthic habitat from fully recovering and therefore the direct loss of offshore benthic habitat is long term. Between dredging events, opportunistic benthic species will start to recolonise the seabed (1), however, species diversity will take longer to recover. The offshore benthic habitat is widespread in the West Africa region and within the study area. The offshore benthic habitat is very common and widespread in the West African region. The magnitude of direct loss of offshore benthic habitat is considered medium since a small proportion of the benthic habitat will be lost under the dredge and dredge disposal footprint and the function of that area will be affected; however, the long-term viability of the habitat and the species dependent on it are not threatened.

Offshore seabed habitats are of low value. The magnitude of impact of direct loss of seabed habitat on offshore benthic habitats is considered to be medium. Therefore the impact will be minor significance prior to mitigation.

Coastal and Estuarine Habitat Dredging of the coastal and estuarine section of the access channel, turning basin and berths will result in a direct loss of coastal and estuarine habitat during both construction and operation. Direct impacts of loss of coastal and estuarine habitat (not including the littoral habitats, which are discussed below) will occur through the same mechanisms as for the offshore benthic environment. As with the offshore environment, the coastal benthic habitat is not expected to fully recover within the dredging footprint as maintenance dredging will be performed regularly throughout the life of the project. A number of medium and high value species are present in the coastal and estuarine habitat, which has a relatively rich biodiversity. A proportion of the coastal and estuarine habitat within the port study area will be permanently lost, especially the benthic habitat within the estuary (see Figure 13.1) and a change in the local abundance and diversity of species may occur as a result, especially in local populations that are adapted to the Morebaya estuary. However, coastal and estuarine habitats are widespread in the West Africa region and some mobile species that are not restricted to the Morebaya estuary may find alternative similar habitat nearby. The coastal and estuarine habitat supports a variety of high and medium value species. The magnitude of direct loss of coastal and estuarine habitat is considered medium as a significant proportion of the local benthic habitat will be lost under the dredged footprint and the function of that area will be affected permanently; however, the long-term viability of the wider habitat and species dependent on it are not threatened.

Coastal and estuarine habitats are of medium value. The magnitude of impact on coastal and estuarine habitats will be medium. Therefore the impact is assessed as being of moderate significance prior to mitigation.

(1) Newell, R.C., Seiderer, L.J. and Hitchcock, D.R. (1998). The impact of dredging works in coastal waters: A review of the sensitivity to disturbance and subsequent recovery of biological resources on the sea bed. Oceanography and Marine Biology: an Annual Review 1998, 36,127-178.


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Intertidal Mudflats and Sandbanks A number of sandbanks and a proportion of mudflat will be directly lost under the access channel dredge footprint. Loss of this habitat will be permanent since the channel will be maintained at depth throughout the life of the project. Further indirect loss may also occur (see Section 13.4.8). Mudflats and sandbanks are common within the port study area and wider region and only a small proportion will be lost. Mudflats and sandbanks support species specifically adapted to the habitat type (eg wading birds, fish and invertebrates). The magnitude of direct loss of mudflats and sandbanks is considered small as although the area available will be reduced locally the long-term viability of the wider habitat and species dependent on it is not threatened.

Intertidal mudflats and sandbanks are considered to be medium value. The magnitude of impact of direct habitat loss of intertidal habitats is considered small. Therefore the impact is assessed as being of minor significance prior to mitigation.

Sandy Beach Habitats No direct loss of sandy beaches will occur due to port activities therefore no impact from direct habitat loss is expected. The impacts of indirect loss of sandy beaches is discussed in Section 13.4.8. Mangrove Habitats Direct loss of mangrove habitat will occur at the MOF and port site. A loss of approximately 8 ha of mangrove has been assessed as part of the MOF SEIA. In addition there is a further 58 ha of mangrove within the port boundary, which may be lost due to construction and access requirements, although it is unlikely the full 58 ha will be cleared. The mangrove lost will be near the MOF site, alongside the export wharf, along the conveyor corridor and near the rail loop. Much of the mangrove in the study area has already been altered by human activities and represents a degraded secondary habitat. Loss at the port location represents a significant loss of the total available mangrove habitat in the immediate area, which is limited in the immediate port vicinity. However, within the wider region there is other similar mangrove habitat available. Mangrove habitat is considered to be of medium value as it supports species specifically adapted to the habitat type and communities that are highly specialised (1) and have a rich biodiversity. Mangroves also provide spawning and nursery areas for a variety of fish and invertebrate species (2). The magnitude of direct loss of mangrove habitat is considered medium since a proportion of the habitat will be lost under the port footprint; however, the long-term viability of mangrove habitat within the Morebaya River and Ile Kaback, including species dependent on it, is not threatened.

Mangrove habitats are considered to be of medium value. The magnitude of impact of direct habitat loss of mangrove habitat is considered medium. Therefore the impact is assessed as being of moderate significance prior to mitigation.

(1) Projet Simandou - Étude de caractérisation sociale et environnementale de base pour le port – Rapport provisoire. Dossier No: 604917. SNC Lavalin Environnement, Décembre 2008. (2) Mangrove.org (n.d.) Ecological Importance of Mangrove Habitat. Available at http://mangrove.org/video/Mangroves.pdf


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13.4.2.3 Impact of Habitat Loss on Fauna Marine Mammals Cetacean species that may occur in West Africa are wide ranging and unlikely to occur frequently within the port study area. The impact of direct loss of habitat is therefore considered of negligible magnitude and is not reported further. However, the West African manatee, considered to be a medium value species as it is listed as Vulnerable on the IUCN Red List, is known to feed in mangrove areas and a proportion of the local mangrove habitat will be lost during port construction. There is extensive suitable habitat for manatees in Guinea and the species is known to occur in the wider region (1) (2); however, the West African manatee is an elusive animal that has only rarely observed in the vicinity of the proposed port. Given the likely seasonal movements by manatees (see Section 13.3.6.2) and the presence of suitable habitat in the vicinity of the port, a conservative approach to assessment is adopted whereby manatees are assumed to occur within the Project study area. Direct loss of mangroves may therefore cause displacement of manatees to less suitable habitat nearby, which may affect a local manatee group since they often rest together in loose, small groups of two to six individuals.

The West African manatee is considered to be medium value species. The magnitude of direct loss of mangrove habitat on the West African manatee is considered medium. Therefore the impact is assessed as being of moderate significance prior to mitigation.

Marine Birds Littoral habitats, including mudflats, sandbanks, sandy beaches and mangroves, provide important nesting and feeding grounds for many species of birds. The mudflats in the vicinity of port are especially important feeding areas for wading birds. Direct loss of littoral habitat and associated benthic communities may reduce the available feeding and nesting grounds and cause displacement of individuals to other areas. However, bird species found in the study area are not restricted to the immediate vicinity of the port and other similar habitats are available in the region. Notably, the Eurasian curlew is a medium value species listed as Near Threatened by the IUCN. All other marine birds in the study area are of low biodiversity value as they are not listed by the IUCN and are not protected by Guinea. The magnitude of direct habitat loss on birds is considered small as only a small proportion of each species present may be affected and the populations themselves will not be impacted.

Marine bird species are considered to be of low value, except for the Eurasian curlew which is a medium value species. The magnitude of impact of loss of habitat is considered to be small. Therefore the impact is assessed as of being of minor significance for the Eurasian curlew and not significant for all other species prior to mitigation.

Marine Reptiles No direct loss of beaches will occur therefore no impacts to turtles from direct habitat loss is expected. Impacts on turtles from indirect habitat loss are discussed below in Section 13.4.8.2.

(1) Cisse, I., Kpoghomou C.N., Diallo A., Dabo A., Bangoura C.A.K. (2006). Strategy Preliminaire de Conservation du Lamantin Ouest Africain (Trichechus senegalensis). Plan de Redaction des Rapports Nationaux. République de Guinée. Wetlands International et Programme des Nations Unies pour l’Environnement (PNUE). (2) Powell, J. & Kouadio, A. (2008). Trichechus senegalensis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. Available at www.iucnredlist.org - last accessed 29 July 2011.


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Benthos Loss of benthic organisms will be caused by direct removal of seabed sediments during the dredging, as a result of smothering of the seabed during disposal of dredged material and by sediment plumes caused by dredging and disposal settling onto the seabed. Many benthic organisms are able to survive a thin covering of sediment or will be able to move away, burrow upwards or extend siphons into the water column. However, near the dredger and at the dredge disposal site the sedimentation will be extensive and the benthos within this footprint will be lost. Dredging activities have been found to lead to a 30-70% reduction in species diversity and a corresponding 40-95% reduction in the abundance of individuals (1). Given that the region is characterised by naturally high turbidity levels the benthic community is likely to be adapted to a degree of sedimentation but unlikely to be tolerant of the high sedimentation rates caused by the dredging and disposal activities. Recovery of benthic communities following disturbance depends on the nature of the new sediment as well as the sources and types of re-colonising animals or vegetation. Research has shown that re-establishment of the benthic community in soft sediments may take up to three years (2) (see Figure 13.12). Maintenance dredging will, however, be performed regularly throughout the lifetime of the Project preventing full recovery of the communities within the dredging and disposal footprints between dredging events and changing the characteristic fauna of these areas to one dominated by opportunistic species such as polychaetes. Recovery rates are generally rapid in highly disturbed sediments in estuaries that are dominated by opportunistic species, and in areas of high sediment mobility (3) such as the proposed access channel. Maintenance dredging has been shown to have a short term effect on the animal communities of muddy sediments and recovery of the new community structure is likely to begin within one month. Partial recovery at the disposal site is possible as the volume of sediment to be disposed of during port operations will be less than during construction and it is likely that areas within the disposal site may not be subject to sediment disposal during each maintenance programme. Overall, there will be a reduction in benthic productivity and a change in community structure within the footprint of the dredged areas and disposal site.

(1) Newell, R.C., Seiderer, L.J. and Hitchcock, D.R. (1998). The impact of dredging works in coastal waters: A review of the sensitivity to disturbance and subsequent recovery of biological resources on the sea bed. Oceanography and Marine Biology: an Annual Review 1998, 36,127-178. (2) Newell, R.C., Seiderer, L.J. and Hitchcock, D.R. (1998). The impact of dredging works in coastal waters: A review of the sensitivity to disturbance and subsequent recovery of biological resources on the sea bed. Oceanography and Marine Biology: an Annual Review 1998, 36,127-178. (3) UK Marine SACs Project. Available at http://www.ukmarinesac.org.uk/activities/ports/ph5_2_2.htm - last accessed May 2012.


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Figure 13.12 Typical Recovery Times of Benthic Macrofauna Populations after Dredging

Source: Based on Newell et al (2004) (1).

The magnitude of direct loss of habitat on benthic organisms is considered to be medium since a proportion of the benthic populations within the study area will be affected and a change in local abundance and distribution over the long-term will occur. However, the benthic populations themselves and the species dependent on them are widespread and abundant and considered to be of low value and therefore will not be significantly affected.

All benthic species in the port study area are considered to be of low value. The magnitude of impact is medium. Therefore the impact of direct habitat loss on benthic species is considered to be of minor significance prior to mitigation.

Fish Fish species may be displaced through direct habitat loss when suitable habitat types (as determined by depth and sediment particle size distribution) and food availability become more limited. The loss of benthic food sources (as described above) may affect the distribution of bottom feeding fish species. However, few high biodiversity value fish species are thought to be regularly present in the study area in large numbers. The fish likely to be present within the dredge and dredge disposal area are typically wide-foraging, spending

(1) Newell, R.C., Seiderer L.J., Simpson, N.M., and Robinson, J.E. (2004). Impacts of marine aggregate dredging on benthic macrofauna off the south coast of the United Kingdom. Journal of Coastal Research, 20(1), 115–125. West Palm Beach (Florida).


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only part of their life cycle within the project footprint and are not dependent only on the study area. The benthic habitats in the region are common and have a broad geographic extent with similar habitat nearby. As described above, benthic productivity within the Project footprint will be reduced in the long term as maintenance dredging will prevent the benthic habitat from fully recovering after dredging. Fish species within the study area are of low, medium or high value depending on their conservation status (see Section 13.3.6 for species within these categories). The magnitude of impact from direct loss of habitat on fish is considered to be small since only a small proportion of fish will be affected and the populations themselves will not be markedly impacted.

The magnitude of direct habitat loss on fish is considered small. For high value fish species the impact is assessed as being of moderate significance. For medium value fish species the impact is assessed as being of minor significance prior to mitigation. For low value species the impact is assessed as not significant.

13.4.3 Direct Impacts: Mortality and Injury to Animals 13.4.3.1 Overview Marine mammals and turtles may be at risk of collision with project vessels, including dredgers, which can cause non-lethal or lethal injuries. In addition, fish and turtles may become entrained by the draghead of the dredger. Impacts from collision and entrainment may occur during both construction and operation and therefore the assessment covers both Project phases. Marine Mammals Collisions between project vessels moving to and from the port and whales, dolphins and the West African manatee may occur. However, the risk of collisions between cetaceans and project vessels is small since many species display an active avoidance response to vessels and they are generally sufficiently mobile to avoid collisions. The greatest risk of collision between a cetacean and a vessel occurs when vessels travel at high speed. Research has indicated that while all sizes and types of vessels can hit whales, most lethal or severe injuries are caused by large vessels (more than 80 m long) travelling at more than 14 knots (1). Collisions occur rarely with vessels travelling below 10 knots. Many of the cetacean species in the Guinea region will occur only rarely in coastal and estuarine areas where vessel traffic is likely to be most intense and the opportunity for avoidance is restricted by water depth and shorelines. Most species occur in deeper offshore areas where avoidance behaviour is likely to be more successful. The exception is the Atlantic humpbacked dolphin which is the cetacean potentially most at risk due to its preference for inshore habitats. However, given that iron ore vessels travel in offshore areas at speeds of approximately 14 knots and will travel at considerably slower speeds within the shipping channels and in other inshore areas there is a low likelihood of collisions between those vessels and cetaceans. Similarly, the dredgers will be operating and transiting to the sediment disposal area at speeds less than 10 knots. Other Project vessels may travel faster than 14 knots but will be small in size. Importantly, cetaceans have a low abundance in the study area and are not expected to occur in the port study area frequently. Cetaceans that may occur within the study area are of low, medium or high value depending on their conservation status. See Section 13.3.6 for species within these categories. The magnitude of collisions with cetaceans is considered small as only a few individuals within the overall populations may be affected and the populations themselves will not be significantly impacted. In addition, the likelihood of collision is very small given the expected speed of vessels and the rare occurrence of the cetaceans within the port study area.

(1) Laist, DW., Knowlton, AR., Mead, JG., Collet, AS. and Podesta, M. (2001). Collisions between ships and whales. Marine Mammal Science. 17(1): 35-75.


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Cetaceans that may occur within the study area are of low, medium or high value depending on their conservation status. The magnitude of collisions with cetaceans is considered small. Prior to mitigation the impact is therefore assessed as being not significant for low value species, of minor significance for the Atlantic humpback dolphin and other medium value species and of moderate significance for high value species.

The West African manatee may occur in mangrove creeks and channels within the Morebaya River, as well as coastal waters, and is therefore at risk of collisions with project vessels operating in the river and along the coast. Manatees may be particularly vulnerable to collisions with vessels due to their slow movement. In the absence of information pertaining to the West African manatee, this assessment is based on research on the West Indian Manatee (Trichechus manatus), which is similar in appearance and behaviour (1). Injury and mortality due to collisions with boats is a major issue for West Indian manatees in Florida, where there is heavy vessel traffic (2). About half of adult West Indian manatee mortality is attributable to human-related causes, primarily watercraft collisions. This is significant as the manatee population growth rate is highly sensitive to changes in adult survival rate. Sub-lethal effects from collisions are also an issue as injuries may reduce the breeding success of wounded females and may permanently remove some animals from the breeding population (3). Inadequate hearing sensitivity at low frequencies may be a contributing factor to the manatees’ inability to effectively detect boat noise and avoid collisions (4). The West African manatee is a medium value species as it is listed as Vulnerable on the IUCN Red List. The magnitude of collisions on manatees is considered medium as although likelihood of collision is low a change in local abundance may occur over the lifetime of the Project.

The West African manatee is considered to be of medium value. The magnitude of impact of collisions with project vessels and the West African manatee will be medium. Therefore the impact is assessed as being of moderate significance.

Marine Reptiles Sea turtles are not expected to occur as far into the estuary as the port site. However, collisions with vessels moving to and from the port or entrainment by dredgers may occur. In the event of a collision or entrainment turtles may be fatally injured, even from relatively slow moving vessels. It has been shown in a study by Hazel et al. (2007) that the proportion of Green turtles (Chelonia mydas) successfully fleeing to avoid vessels decreased significantly as vessel speed increased (5). Turtles that fled from moderate and fast approaches did so at significantly shorter distances from the vessel than turtles that fled from slow approaches. Turtles should therefore not be relied on to actively avoid collision with vessels moving in excess of 4 km/h (2.2 knots) (6). The likelihood of a turtle resting in the active path of a dredger and the subsequent risk of entrainment into the drag head is very small. However, if entrainment were to occur there is a risk of injury or death.

(1) Reynolds, J.E. III and D.K. Odell. (1991). Manatees and dugongs. Facts on File, New York. 192pp. (2) Calleson, C.S. and Frohlich, R.K. (2007). Slower boat speeds reduce risks to manatees. Endangered Species Research, 3, 295-307. (3) Deutsch, C.J., Self-Sullivan, C. & Mignucci-Giannoni, A. (2008). Trichechus manatus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. Available at www.iucnredlist.org - last accessed 29 July 2011. (4) Gerstein, ER. Gerstein, L., Forsythe, SE. and Blue, JE. (1999). The underwater audiogram of the West Indian manatee (Trichechus manatus). Journal of the Acoustical Society of America, Volume 105, Issue 6, pp. 3575-3583. (5) Hazel, J., Lawler, I.R., Marsh, H. and Robson, S. (2007). Vessel speed increases collision risk for the green turtle Chelonia mydas. Endangered Species Research 3: 105–113, 2007. (6) Hazel, J., Lawler, I.R., Marsh, H. and Robson, S. (2007). Vessel speed increases collision risk for the green turtle Chelonia mydas. Endangered Species Research 3: 105–113, 2007.


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Monitoring studies (1) of turtle entrainment by hydraulic dredgers in the US from 1995 - 2008 suggest a maximum entrainment rate of 22 turtles per 1 000 000 m3 of dredge material. While turtles do not occur in the port study area in large numbers, five species of turtle are known to occur in the region and there is a potential negative impact. Hawksbill, Leatherback, Loggerhead and Green turtles are considered to be of high biodiversity value due to their Endangered IUCN status, and the Olive Ridley sea turtle is medium value due to being listed as Vulnerable on the IUCN Red List. The magnitude of vessel collision and entrainment on sea turtles is small as only a few individuals may be affected and the overall population is not expected to be affected.

Turtles are considered to be of high value, except the Olive Ridley sea turtle which is medium value. The magnitude of impact of collisions of turtles with project vessels, taking into consideration the likelihood of occurrence, is small. Therefore the impact is assessed as being of minor significance for the Olive Ridley sea turtle and moderate significance for Hawksbill, Leatherback, Loggerhead and Green turtle species prior to mitigation.

Fish Individual fish may be killed or injured through entrainment by the draghead of the dredger. Slow moving bottom-dwelling fish species are most at risk as they may not be able to move away from the draghead; however, many fish species will be able to actively avoid the draghead. Fish species within the port study area are of low, medium or high value depending on their conservation status, as described in Section 13.3.6.5. The magnitude of impact of direct fatalities or injury on fish is considered to be small because only a small number of individuals of some fish species will be affected but the populations themselves will not be impacted.

The magnitude of direct mortality or injury to fish is considered small. Prior to mitigation the impact is assessed as being of moderate significance for high value fish species, minor significance for medium value fish species and not significant for low value species.

13.4.4 Direct Impacts: Noise 13.4.4.1 Overview Underwater noise can affect species distribution, behaviour and potentially cause hearing damage. Construction and operation activities have the potential to affect species that occur in the offshore, coastal and estuarine environments. Underwater noise during construction may arise from pile driving, dredging, and from vessel engines and thrusters. Table 13.13 presents typical underwater noise levels from activities that will occur during port construction. Noise propagation modelling for pile driving, which will only take place during construction within the Morebaya River, suggests impacts from pile driving will not extend outside of the river. Pile driving will represent a significant noise source during the construction phase of the port but is unavoidable as it is required to establish structural support for the infrastructure and will be required for the construction of the stilted export wharf within the Morebaya River. Pile driving will take place 24 hours a day over a period of nine months. Table 13.13 presents typical pile driving noise levels, although actual noise levels vary with pile size, pile driving method and local geology.

(1) Reine, K. and Clarke, D. (1998). Entrainment by hydraulic dredges-A review of potential impacts. Technical Note DOER-El. U.S. Army Corps of Engineers, Environmental Laboratory, Vicksburg, MS.


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Ship-related engine and thruster noise will be continuous throughout the construction period due to the various vessels required, including vessels for transporting construction materials and equipment, dredgers and supply and fuel vessels. The exact underwater noise characteristics of vessels depend on the ship type, size, mode of propulsion, operational characteristics and speed as well as other factors (1). Much of the incidental noise is a result of propeller cavitation, although onboard machinery and turbulence around the hull can also result in transmission of underwater noise. The noise produced by the dredgers depends on their operational status, the seabed removal method and the type of sediment and sediment dumping methods (2). In general, the noisiest activity is associated with seabed removal due to continuous emission of broadband sound, mostly in the lower frequencies. Dredging for the port construction will be continuous for 36 months. Table 13.13 presents typical vessel noise for a range of vessel sizes similar to those that may be used for the port construction and operation. Underwater noise during port operation will arise from maintenance dredging and from vessel engines and thrusters. The type of noise impacts will be similar to those occurring from vessels and dredging during the port construction phase although the number of vessels is expected to be less during port operations. It is expected that two iron ore vessels will enter the Morebaya River every three days once the port is operational, and a variety of supply, fuel and other small vessels will be used. Maintenance dredging will require fewer vessels over a shorter time period compared to the capital dredging operations during port construction. Table 13.13 Typical Noise Levels

Sound source Source level (dB re 1μPa m) at 1 m

Bandwidth (Hz) Major amplitude (Hz) Duration (ms)

Small boats and ships

160 – 180 rms (root mean square)

20 - >10 000 >1000 Continuous

Large vessels 180-190 rms 6 - >30 000 >200 Continuous

Dredging 168 – 186 rms 30 - >20 000 100-500 Continuous

Pile driving 228 Peak

243 – 257 Peak-Peak

20 - >20 000 100-500 Impulse, 50

Note: see glossary for an explanation of the different noise metrics. Source: OSPAR, 2009 (3)

Marine Mammals The response of different marine mammal species to underwater noise will depend on their hearing ability and the distance to the noise source. In addition, cetacean behavioural response to noise will depend on the individual’s age, condition, behaviour, season, social state and sex (4). Behavioural effects can range from visible acknowledgement that a sound has been heard, such as a brief startle response, through to strong and prolonged avoidance behaviour. Most commonly, marine mammals react to noise by changing their behaviour, such as their direction and / or speed of movement or by altering vocalisation patterns. In exceptional cases, underwater noise can result in physical effects to cetaceans. The zone of physical effect is the area where the received sound level is high enough to cause auditory fatigue, tissue damage resulting in temporary hearing loss, permanent hearing loss or more severe internal damage. An underwater noise assessment has been carried out to determine potential zones of impact on the cetacean species present. Threshold levels of noise at which impacts may occur on cetacean species have

(1) Götz, T., Hastie, G., Hatch, L.T., Raustein, O., Southall, B.L., Tasker, M. and Thomsen, F. (2009). Overview of the impacts of anthropogenic underwater sound in the marine environment. OSPAR Commission Biodiversity Series. (2) Wyatt (2008). Joint Industry Programme on Sound and Marine Life Review of Existing Data on Underwater Sounds Produced by the Oil and Gas Industry Issue 1 (3) Götz, T., Hastie, G., Hatch, L.T., Raustein, O., Southall, B.L., Tasker, M. and Thomsen, F. (2009). Overview of the impacts of anthropogenic underwater sound in the marine environment. OSPAR Commission Biodiversity Series. (4) Thomsen, F., Lüdemann, K., Kafemann, R. and Piper, W. (2006). Effects of offshore wind farm noise on marine mammals and fish, Biola, Hamburg, Germany on behalf of COWRIE Ltd.


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been used to model predicted zones of impact around activities associated with port construction and operation, as described fully in Annex 13B: Port Study Area Underwater Noise Scoping Report and summarised below. In order to cause instantaneous injury to cetaceans resulting in a permanent loss in hearing ability (or

permanent threshold shift, PTS), the underwater sound level must exceed 230 dB re 1 μPa (peak) (1). Temporary Threshold Shift (TTS) is considered to be auditory fatigue that results in a short term loss of

hearing sensitivity rather than permanent hearing damage. The 180 re 1 μPa (rms) level for TSS has not been considered to be the level above which TTS might occur, but rather that it could not be ruled out.

For noise levels at which a significant behavioural response is likely, a threshold of

160 dB re 1 μPa (rms) for pulsed sounds (such as piling) and 120 dB re 1 μPa (rms) for non-pulsed sounds (such as dredging and vessel noise) is adopted.

Based on modelling using the above criteria, the predicted distance within which cetaceans may experience permanent injury from a single pile driving event is less than 10 m. The zone within which TTS is possible extends to 100 m from the source, while behavioural disturbance from piling may occur at up to 2 km. Behavioural responses of cetaceans to dredging and vessel noise could theoretically occur up to 46 km from the activity. Pile driving operations will take place approximately 5 km up the Morebaya River which, given the impact zone may only affect the Atlantic humpback dolphin since the other cetacean species are not expected to occur within the estuary. Pile driving will continue 24 hours a day over the course of 9 months, but actual pile driving events will be intermittent, with quiet periods while equipment is moved between piles. It is unlikely PTS will occur as piling noise is unlikely to exceed the 230 dB re 1 μPa (peak) threshold (see Table 13.13) and animals would have to be in very close proximity to the pile for PTS to occur. TTS, however, may occur if the animal is within 100 m of the piling activities and behavioural responses may occur near the estuary mouth. Given the low occurrence of the Atlantic humpback dolphin in the study area, only a few individuals at most are expected to be exposed to pile driving noise. The zone where there is potential for behavioural effects from vessel and dredging noise is much wider than for pile driving and may affect cetaceans over a wide area during port construction and operation. Although cetaceans are thought to occur infrequently and at low abundances in the study area, it is likely that some may be found within the vessel noise impact zone at some point during construction and operation. All cetacean species that may occur in the study area have wide foraging ranges and it is unlikely that any behavioural response, either to piling or vessel noise, would have an impact on their populations. Cetaceans that may occur within the study area are of low, medium or high value depending on their conservation status. However, most cetaceans are only likely to occur within the port study area rarely. The magnitude of habitat degradation through underwater noise is considered small during both construction and operation as only a small proportion of the overall populations may be affected but the populations themselves will not be impacted.

Cetaceans that may occur within the study area are of low, medium or high value depending on their conservation status. The magnitude of habitat degradation through underwater noise is considered small during both construction and operation. Therefore prior to mitigation the impact is assessed as being not significant for low value species, of minor significance for the Atlantic humpback dolphin and other medium value species and of moderate significance for high value species.

Information on the hearing sensitivity of the West African manatee is limited. However, West Indian manatees have a reported hearing ability of between 15 Hz and 46 kHz with the best sensitivity at

(1) Southall, B.L., A.E. Bowles, W.T. Ellison, J.J. Finneran, R.L. Gentry, C.R. Greene Jr., D. Kastak, D.R. Ketten, J.H. Miller, P.E. Nachtigall, W.J. Richardson, J.A. Thomas, and P.L. Tyack. (2007). Marine mammal noise exposure criteria: initial scientific recommendations. Aquatic Mammals 33(4):411-522.


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6 - 20 kHz (1) (2). Other data suggest West Indian manatees are most sensitive around 1 - 1.5 kHZ but are less sensitive at 4 kHz and even 8 kHz, although there was some sensitivity up to 35 kHz (3). Research has indicated that elevated sound levels affect the behavioural patterns of the Florida manatee (a subspecies of the West Indian manatee) (4). In the absence of more specific data it has been assumed in this assessment that the West African manatee is equally sensitive as other marine mammals in the study area. The West African manatee is listed as Vulnerable on the IUCN Red List. The magnitude of noise on manatees is considered medium as, although only a few individuals may be affected, this may change the distribution and local abundance of the species.

The West African manatee is considered to be of medium value. The magnitude of impact from noise is considered medium. Therefore prior to mitigation the impacts from underwater noise are assessed as being of moderate significance.

Marine Birds Airborne noise from piling and vessel activities may cause disturbance to nearby bird populations. The disturbance may cause changes to distribution and behaviour, changes in avian demography and ultimately changes in population size (5). However, there is a large amount of evidence suggesting that disturbance is not a key issue for bird species using intertidal habitat and other studies indicate that bird movements are driven more by food resource issues than anthropogenic disturbance (6) (7). Mild localised behavioural reactions to port construction and operational noise may occur. See Chapter 12: Terrestrial Biodiversity for a more detailed discussion on airborne noise on birds. The Eurasian curlew is a medium value species listed as Near Threatened by the IUCN whereas all other marine birds in the study area are of low biodiversity value since they are not listed by the IUCN and are not protected by Guinean legislation. The magnitude of noise on birds is considered small as only a small number of individuals of each species present may be affected and the populations themselves will not be impacted.

Marine bird species in the study area are considered to be of low value, except the Eurasian curlew which is medium value. The magnitude of impact of noise during construction and operation is considered to be small. Therefore the impact is assessed as not significant for low value birds and of minor significance for the Eurasian curlew prior to mitigation.

Marine Reptiles Annex 13B: Port Study Area Underwater Noise Scoping Report presents the full underwater noise assessment and rationale for impacts on marine and littoral biodiversity. As noted in the Annex 13B there are no reliable data available relating to the noise levels resulting in Temporary Threshold Shift (TTS) or Permanent Threshold Shift (PTS) in sea turtles. For behavioural reactions to piling noise, this assessment

(1) Richardson, JW., Greene, CR., Malme, CI. and Thomson, DH. (1995) Marine Mammals and Noise. Academic Press. 576 pages. (2) Gerstein, ER. Gerstein, L., Forsythe, SE. and Blue, JE. (1999). The underwater audiogram of the West Indian manatee (Trichechus manatus). Journal of the Acoustical Society of America, Volume 105, Issue 6, pp. 3575-3583. (3) Gerstein, ER. Gerstein, L., Forsythe, SE. and Blue, JE. (1999). The underwater audiogram of the West Indian manatee (Trichechus manatus). Journal of the Acoustical Society of America, Volume 105, Issue 6, pp. 3575-3583. (4) Miksis-Olds, J.L. and Wagner, T. (2011). Behavioral response of manatees to variations in environmental sound levels. Marine Mammal Science Volume 27, Issue 1, pages 130–148. (5) Gill, J.A. (2007). Approaches to measuring the effect of human disturbance on Birds. IBIS. 149 Suppl. 1 9-14. (6) Gill, J.A. Norris, K. and Sutherland, W.J. (2007). The effects of disturbance on habitat use by black-tailed godwits Limosa limosa’, in Journal of Applied Ecology, Vol 38, pp. 846-856. (7) Stillman, R.A. West, A.D. Goss-Custard, J.D. McGorty, S. Frost, N.J. Morrisey, D.J. Kenny, A.J. and Drewitt, A.L. (2005). Predicting site quality for shorebird communities: a case study on the Humber Estuary, UK, in Marine Ecology Progress Series, Vol. 305: 203–217.


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has used a threshold of 166 dB re 1 μPa (rms) for the onset of behavioural responses and 175 dB re 1 μPa (rms) for a likely avoidance reaction. This results in a predicted impact zone of approximately 215 m to 858 m from the piling location. Sea turtles are not expected to commonly occur within the estuary close to the port site and impacts from piling noise are therefore not expected. It is not possible to quantitatively assess impacts from dredging and vessel noise due to the difficulties in separating turtle responses due to visual disturbance from those due to noise. Hawksbill, Leatherback, Loggerhead and Green sea turtles are considered to be of high value due to their IUCN status (Critically Endangered and Endangered). The Olive Ridley sea turtle is medium value as it is listed as Vulnerable on the IUCN Red List. However, the magnitude of noise impacts from piling on sea turtles is expected to be negligible since few turtles are expected in the vicinity of the port during construction and operation and the relatively small zone of impact. Noise impacts from dredging and vessel activities on turtles have not been assessed.

Turtles are considered to be of high value, except for the Olive Ridley sea turtle, which is medium value. The magnitude of piling noise impacts on sea turtles during construction and operation is negligible. The impact is therefore assessed as being not significant for all turtle species.

Fish Underwater noise can impact fish by altering distribution of species / individuals and affecting hearing. Different fish species are known to respond differently to underwater noise, with impacts ranging from behavioural response (eg vacating or avoiding the area) to death. Elasmobranchs, such as rays and sharks (including guitarfish) that have no swim bladder, tend to have relatively low auditory sensitivity and are referred to as hearing generalists. Other species with physiological adaptions that increase hearing sensitivity are known as hearing specialists. Both hearing specialists and hearing generalists are acknowledged in the assessment, where appropriate. An underwater noise assessment has been carried out to determine potential zones of impact on the species present, with the full assessment presented in Annex 13B: Port Study Area Underwater Noise Scoping Report. A summary is presented below. The Fisheries Hydro Acoustic Working Group (FHWG) (1) has established interim criteria for the potentially lethal effects on fish. Only pile driving exceeds the noise threshold that may be lethal to fish (206 dB re 1 μPa (peak) and for SEL 187 dB re 1µPa2 s for fish weighing more than 2 g and 183 dB re 1µPa2 s for fish weighing less than 2 g). The SEL criteria are intended to take into account the likely noise exposure over time, which would require more detailed knowledge of likely timings of activities than is available at this stage of the project. It is considered unlikely that severe physical damage will occur to fish due to dredging, vessel engine and thruster noise since noise from these sources is expected to be below the levels that could cause damage. While there is no widely agreed threshold noise level for the onset of behavioural responses in fish, a conservative measure of 150 dB rms has been used by National Oceanographic and Atmosphere Administration (NOAA) Fisheries and US Fish and Wildlife Service (USFWS). This threshold is used here to indicate the zone of potential behavioural reactions. Physical damage due to pile driving noise may occur if fish are in very close proximity to the piling location. Marine pile driving has been shown to produce high sound pressures underwater, which have fatally injured fish (2). Fish are not expected to experience injury as a result of the pile driving work in areas beyond approximately 18 m from the source during individual pile strikes. If it is assumed that fish do not move away from the source of noise and therefore experience cumulative exposure, the impact zone is 6.8 km for fish with mass greater than 2 g, and approximately 10 km for smaller fish, in which case large numbers of fish in the river and estuary may be affected. However, it is more likely that fish will move away from the source of the noise and only small numbers of fish will remain close enough to experience fatal effects or injury. This may create a large zone of displacement around the piling activities, which will affect a large number of fish.

(1) California Department of Transportation (2009). Technical Guidance for Assessment and Mitigation of the Hydroacoustic Effects of Pile Driving on Fish. Prepared by: ICF Jones & Stokes and Illingworth and Rodkin, Inc. (2) Reyff, J.A. (2009). Reducing underwater sounds with air bubble curtains. TR News 262:31-33.


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Behavioural responses to noise below the lethal level from any of the aforementioned construction activities, including the displacement described above, may affect fish over nine months for piling and 37 months for dredging while the port is undergoing construction. The modelled zone of impact for behavioural reactions, using a conservative threshold of 150 dB rms, is approximately 10 km for piling activities and 465 m for dredging and vessel movement. The zone of impact for dredging is small around the dredgers and will be transient as the dredgers move position; therefore impacts on fish species will be less than for pile driving. Depending on fish hearing ability and the distance from the noise source, fish may show either strong or mild behavioural reactions to noise. Of the fish species present in the Morebaya River and coastal environment, fish with more sensitive hearing mechanisms may react several kilometres from the source (1). The majority of fish do not have specialisations to enhance hearing and are therefore assumed to be less sensitive; these hearing generalists will have smaller behavioural response zones. Fish are likely to return to the area once pile driving has ceased and are known to habituate to some noise sources. However, the impact zone for behavioural effects from pile driving, especially on smaller fish, will cover the majority of the Morebaya estuary and will extend into coastal waters. This will affect large numbers of fish, and may potentially result in total avoidance of the area by more sensitive species, which is likely to affect spawning behaviour and recruitment given the expected nine month pile driving programme. The majority of fish species affected are likely to be species tolerant of a range of conditions and able to make use of other similar habitats within the area. Fish species within the study area are of low, medium or high value depending on their conservation status. The magnitude of impact of underwater noise on fish is considered to be medium during the nine month pile driving programme since a variety of fish species will be affected across a wide area for a relatively long period of time. The magnitude of impact of noise on fish is considered to be small during port operation since piling will not be undertaken.

Fish species within the study area are of low, medium or high value depending on their conservation status. The magnitude of impact of underwater noise on fish is considered to be medium during construction and small during operation. During construction the impact is therefore assessed as being of major significance for high value species, moderate significance for medium value species and minor significance for low value species prior to mitigation. During operation the noise impact is therefore assessed as being of moderate significance for high value species, minor significance for medium value species and not significant for low value species.

13.4.5 Direct Impacts: Altered Water Quality 13.4.5.1 Overview Impacts on water quality during construction and operation are assessed in Chapter 7: Marine and Littoral Physical Environment. The dredge and dredge disposal plume has been assessed to result in moderate impacts on water quality during construction and minor impacts on water quality during operation pre-mitigation. During construction, dredging is planned to occur 24 hours a day seven days a week for 36 months using up to seven dredgers. Concentrations of nutrients and contaminants in the water column are not expected to increase significantly because the quality of the sediment to be dredged is generally good and recent water quality results indicate relatively high levels of some metals in the water column, probably as a result of the naturally high suspended sediments in the area. The region is characterised by naturally high suspended sediment concentrations (in excess of 400 mg/l offshore) caused by the river outflow, wave action, tidal currents and the fine sediment characteristics (see Chapter 7: Marine and Littoral Physical Environment).

(1) Popper AN, Hastings MC. (2009). The effects of anthropogenic sources of sound on fishes. Journal of Fish Biology 75:455-489.


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Suspended sediments in the dredging plumes are therefore the main concern. Modelling results indicate that elongated plumes from dredging are likely to remain visible for up to a couple of days as they gradually mix with the surrounding water. However, individual plumes from different dredgers and different days are likely to interact because the continuity of dredging operations (over a 37 month period) will cause the development of sediment plumes throughout the entire dredging period preventing complete dispersal of sediment plumes during that period. The plumes developed during construction are expected to be more extensive than during operation given the larger volumes of sediment to be dredged and the larger number of dredgers working during the capital dredging activities. Even though the region is characterised by already high suspended sediment concentrations, impacts on water quality from the sediment plumes are expected. Marine Mammals Most cetaceans predominantly occur in the offshore pelagic environment, which may be affected by habitat degradation through changes in water quality. The Atlantic humpback dolphin favours inshore environments and may occasionally occur several kilometres into the Morebaya River. However, cetaceans in the port study area are considered rare visitors. Changes in water quality as a result of the port construction and operation are not expected to affect cetaceans given their infrequent occurrence near to the port and their large ranges. The Atlantic humpback dolphin is also unlikely to be affected by changes in water quality as it is tolerant of the naturally high levels of turbidity experienced in coastal waters, although dredging activities will elevate suspended sediments for a period of 36 months during construction and for several months each year during port operations. Cetaceans that may occur within the study area are of low, medium or high value depending on their conservation status. See Section 13.3.6 for species within these categories. The magnitude of impacts from altered water quality is considered negligible during both construction and operation as populations are not expected to be affected and turbidity levels are naturally high.

Cetaceans that may occur within the study area are of low, medium or high value depending on their conservation status. The magnitude of impacts from altered water quality is considered negligible during both construction and operation. The impact of altered water quality is assessed as being not significant for all cetacean species.

The West African manatee also inhabits naturally turbid environments in estuarine and river environments. The West African manatee is a medium value species as it is listed as Vulnerable on the IUCN Red List. The magnitude of impact from altered water quality is considered to be negligible as turbidity levels are naturally high.

The West African manatee is a medium value species. The magnitude of impact from altered water quality is considered to be negligible. The impact of altered water quality is assessed as being not significant for the West African manatee.

Marine Birds The effects of reduced water quality in offshore, coastal and estuarine waters on birds may include a reduction in the size of local feeding grounds. The sediment plumes may cause displacement of individuals as diving birds such as cormorants and terns which are present along the Morebaya River and in the surrounding area may be less successful in feeding due to the increased turbidity and may move to areas with less turbid waters. However, the coastal waters in the vicinity of the port have a naturally high turbidity and marine birds in the area are likely to be adapted to feeding in turbid conditions. Furthermore, most bird species are wide ranging and it is likely that their prey will also avoid areas with particularly high turbidity, where possible. Individuals will therefore be able to avoid the plume and feed in areas with lower turbidity, returning along with their prey to the affected area once turbidity has returned to background levels.


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The Eurasian curlew is a medium value species listed as Near Threatened by the IUCN. All other marine birds in the study area are of low biodiversity value as they are not listed by the IUCN and are not protected by Guinea. The magnitude of impact of altered water quality on birds is considered negligible as coastal waters are naturally turbid and populations are unlikely to be affected.

Marine bird species in the study area are considered to be of low value, except the Eurasian curlew which is medium value. The magnitude of impact of altered water quality during construction and operation is considered to be negligible. Therefore the impact of altered water quality is assessed as not significant for marine bird species.

Marine Reptiles Degradation of offshore, coastal and estuarine waters may impact on sea turtles through changes in water quality including increased turbidity and contaminants from the sediment plume. Increased turbidity may result in avoidance of areas with turbidity levels elevated well above natural background levels, which may result in decreased foraging success. However, sea turtles are wide ranging and it is unlikely that their foraging success will be decreased, especially given that the study area is not considered an important area for turtles as they have only been reported to occur infrequently in low numbers. Impacts will be similar during both construction and operation, although during operation the extent of sediment plumes will be reduced. Turtles are not expected to be commonly present within areas most affected by altered water quality, and individuals will actively avoid areas that are unsuitable. In addition the region is characterised by naturally turbid waters. Hawksbill, Leatherback, Loggerhead and Green sea turtles are considered to be of high value due to their IUCN status (Critically Endangered and Endangered). The Olive Ridley sea turtle is medium value as it is listed as Vulnerable on the IUCN Red List. The magnitude of impact from altered water on sea turtles is negligible since few turtles are expected in the vicinity of the port and the area is characterised by high turbidity levels.

Hawksbill, Leatherback, Loggerhead and Green sea turtles are considered to be of high value. The Olive Ridley sea turtle is medium value. The magnitude of altered water quality on sea turtles is negligible during construction and operation. The impact is therefore assessed as being not significant for all sea turtles.

Fish Fish may be affected by water quality changes in offshore, coastal and estuarine waters, which may affect fish distributions and prey availability. Impacts from changes in water quality will start during construction and continue throughout operation. Increased turbidity within the dredging plumes will cause some fish to move away in attempt to avoid high suspended sediments that can clog gills and irritate membranes. However, the coastal waters near the study area are characterised by high sediment loads and fish species that regularly occur in the region will be generally tolerant of high suspended sediment concentrations. The tides and waves should ensure sufficient mixing of the water column in the shallow areas to avoid development of low oxygen conditions that can sometimes occur during dredging operations and can be lethal to fish. Fish species within the study area are of low, medium or high value depending on their conservation status. High value species are those listed as Critically Endangered or Endangered on the IUCN Red List. Medium value species are those listed as Vulnerable, Near Threatened, or Data Deficient on the IUCN Red List. Low value species are those listed as Least Concern on the IUCN Red List. A selection of high and medium value fish species is presented in Table 13.10. The magnitude of impact of altered water quality on fish is considered to be medium during construction as a proportion of a population will be affected so that a reduction in distribution and abundance may occur over one or more generations. The magnitude of impact


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of altered water quality on fish is considered to be small during port operations since only a small proportion of the fish populations will be affected and the populations themselves will not be impacted.

Fish species within the study area are of low, medium or high value depending on their conservation status. The magnitude of impact of altered water quality on fish is considered to be medium during construction and small during operation. During construction the impact is therefore assessed as being of major significance for high value species, moderate significance for medium value species and minor significance for low value species prior to mitigation. During operation the impact is therefore assessed as moderate significance for high value species, minor significance for medium value species and not significant for low value species prior to mitigation.

13.4.6 Direct Impacts: Altered Sediment Quality 13.4.6.1 Overview Offshore and coastal / estuarine benthic habitats may be lost or degraded through both the removal of sediment during dredging and the deposition of sediment on the seabed from the plumes created during dredging and sediment disposal. In Chapter 7: Marine and Littoral Physical Environment, impacts on sediment quality are stated as moderate during port construction and minor during port operation. Construction dredging will be more intensive with larger sediment volumes and more dredgers than operational maintenance dredging. Changes in sediment particle size distribution will occur over a wide area due to settlement of fine grained sediments entrained in the sediment plumes. Such changes in sediment particle size can make the habitat unsuitable for species currently using the area in terms of suitable substrate to live in or, change in prey availability. Settlement of sediment can also smother benthic communities. Sedimentation from the dredge plume will be thickest near the dredger, which can smother the habitat and species, but will reduce in thickness with increasing distance from the dredging location. At distance only a thin veneer of sediment is likely, although a change in surface sediment composition may occur several kilometres from the dredged area. Over time, the fine sediments that have settled out of the plume over a wide area will be redistributed by tidal currents and waves and the original seabed characteristics may be restored. Sedimentation from the disposal of sediment at the 15 km2 disposal area will be of a much greater thickness (up to 5 m during the construction period) which will completely smother the seabed habitat in the designated area. Over time, tidal currents and waves will redistribute some of the sediments at the disposal area, with fine material expected to move offshore into deeper waters given the local bathymetry. Due to the lower volumes of sediment to be disposed during the operational phase it is possible that benthos in parts of the disposal area will recover to near baseline conditions once the construction dredging has been completed. However, the bathymetry at the disposal site will be permanently altered. Benthos Sediment-based benthos is considered to be of low value as it is very common and widespread in the West African region and has low conservation significance. The magnitude of impact of altered sediment quality to the benthos during construction is considered medium since a proportion of the benthic habitat will be altered due to dredging and sediment deposition (including sedimentation from the plume) but the long-term viability of the habitat and species dependent on it are not threatened. In contrast, the magnitude of altered sediment impact to the benthos during operational maintenance dredging is considered be less than for the construction period due to smaller volumes of sediment to be dredged and the dredging area will have already been impacted during the construction period.

Benthos is considered to be of low biodiversity value. The magnitude of impact of altered sediment quality on the benthos is medium during construction and small during operation. Therefore prior to mitigation, the impact will be of minor significance during construction and not significant during operation.


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Fish Changes in surface sediment composition from dredging and dredged material disposal may alter the habitat type and affect prey availability for fish species. However, given the wide availability of the offshore, coastal and estuarine habitats in the study area, the foraging success of fish in the area should not be significantly affected. Fish species within the study area are of low, medium or high value depending on their conservation status. High value species are those listed as Critically Endangered or Endangered on the IUCN Red List. Medium value species are those listed as Vulnerable, Near Threatened, or Data Deficient on the IUCN Red List. Low value species are those listed as Least Concern on the IUCN Red List. A selection of high and medium value fish species is presented in Table 13.10. The magnitude of impact of altered sediment quality on fish is considered to be medium during construction as a proportion of a population will be affected so that a reduction in distribution and abundance may occur over one or more generations. The magnitude of impact of altered sediment quality on fish is considered to be small during port operations since only a small proportion of the fish populations will be affected and the populations themselves will not be impacted.

Fish species within the study area are of low, medium or high value depending on their conservation status. The magnitude of impact of altered sediment quality on fish is considered to be medium during construction and small during operation. During construction the impact is therefore assessed as being of major significance for high value species, moderate significance for medium value species and minor significance for low value species prior to mitigation. During operation the impact is therefore assessed as moderate significance for high value species, minor significance for medium value species and not significant for low value species prior to mitigation.

13.4.7 Direct Impacts: Artificial Light 13.4.7.1 Overview Vessels travelling to and from the port site, and those conducting dredging, will emit light during hours of darkness and during poor weather conditions. Light emissions will be continuous in dark periods throughout the construction and operational periods as dredgers and other vessels will be operating 24 hours a day and the port will be lit at night. Vessel movements and maintenance dredging, both at night and in poor weather, will continue during the operation of the port. Marine Birds Artificial light is known to cause deaths of migratory birds around tall lighted structures as well as behavioural responses such as disruption to migration and changes to feeding behaviour (1). Artificial night lighting may also affect the choice of nest site. Given the potentially large numbers of migratory birds that occur along the coast of Guinea and the anticipated light emissions from the port and vessels (in the coastal waters and estuary), some impacts to birds may occur. The Eurasian curlew is a medium value species as it is listed as Near Threatened on the IUCN Red List. Other marine bird species likely to be found in the port study area are of low value as they are not protected or listed and are widespread and/or abundant. The magnitude of artificial light on birds is considered small during construction and operation as only a small proportion of the overall populations may be affected but the populations themselves will not be impacted.

(1) Longcore, T. and Rich, C. (2004). Ecological light pollution. Frontiers in Ecology and the Environment 2: 191–198.


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Marine bird species in the study area are considered to be of low value, except the Eurasian curlew which is medium value. The magnitude of impact of artificial light during construction and operation is considered to be small. Therefore the impact is assessed as not significant for low value birds and of minor significance for the Eurasian curlew prior to mitigation.

Marine Reptiles Sea turtles are not expected to be impacted by light at the port site as they are not expected to occur as far up the Morebaya River as the port. However, dredging and vessel movements throughout the coastal waters may cause some disturbance to turtles as artificial light is known to cause disorientation of hatchling sea turtles and affect the egg laying behaviour of female turtles (1). Light emitted by vessels may result in some localised disturbance, but not to the extent that behavioural changes lead to adverse effects on the population of these animals. Light emissions will be regular throughout the construction and operational period as dredgers and other vessels will be operating constantly. Hawksbill, Leatherback, Loggerhead and Green sea turtles are considered to be of high value due to their IUCN status (Critically Endangered and Endangered). The Olive Ridley sea turtle is medium value as it is listed as Vulnerable on the IUCN Red List. The magnitude of impacts from artificial lighting on sea turtles is small as only a few individuals may be affected, given that turtles are only reported infrequently in low numbers, and the population is not expected to be impacted.

Turtles are considered to be of high biodiversity value, except for the Olive Ridley sea turtle, which is medium value. The magnitude of impacts from artificial lighting on sea turtles is small during construction and operation. The impact is therefore assessed as being of minor significance for the Olive Ridley sea turtle and moderate significance for Hawksbill, Leatherback, Loggerhead and Green sea turtles prior to mitigation.

13.4.8 Indirect Impacts: Indirect Loss of Habitat and Habitat Degradation 13.4.8.1 Overview The main source of indirect loss of habitat and habitat degradation is through potential long-term geomorphological changes resulting from the dredging of ship access channels and subsequent alteration of the sedimentation patterns in the vicinity of the port development. There are also potential impacts from changes to the hydrodynamic circulation patterns in nearshore, estuarine and river environments due to the altered bathymetry as a result of dredging. Other potential sources of indirect habitat degradation are due to the influx of people and domesticated animals into the area in association with construction and operation of the port. Coastal and Estuarine Habitat Coastal and estuarine habitats may be indirectly affected due to changes to the bathymetry as a result of the dredging of shipping access channels. The deepening of the river, estuary and coastal waters for the approach channel will allow saltwater to move further into the estuary than naturally occurs, while freshwater will be channelled from the river out of the estuary and through the shallow coastal waters (2) rather than mixing with the estuarine and nearshore waters under natural conditions. Modelling conducted for the Project suggests there will be an increased salinity in the river in the first 10 km upstream of the river mouth bar due to a pronounced salt wedge that will intrude into the river resulting in salinity increases further upstream in the river. Based on preliminary 3D modelling, the salinity at the most landward part of the transect increases from approximately 12 parts per thousand (ppt) to 25 ppt near the river bed, and from

(1) Longcore, T. and Rich, C. (2004). Ecological light pollution. Frontiers in Ecology and the Environment 2: 191–198. (2) Herbich, JB. (2000). Handbook of dredging engineering. Edition 2, illustrated. McGraw-Hill Professional.


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2 ppt to 7 ppt near the water surface (1). This altered salinity will affect the distribution of intra-estuarine and coastal water habitats. However, given that salinity within the estuary and coastal waters naturally changes with the seasons (eg estuarine salinity changes from 30 to 35 ppt during the dry season to 5 to 18 ppt during the wet season), the estuarine and coastal habitat is likely to be adapted to changes in salinity, although the salinity changes resulting from the port dredging activities will be permanent rather than seasonal. Due to changes in salinity gradients within the river, estuary and nearshore environments, the distribution of marine species, such as mangroves and fish, may change to reflect the new environmental conditions. Saline intrusion into coastal freshwater aquifers may also occur through removal of sediments previously confining the salt water, although this is not considered to affect any marine or littoral habitats. See Chapter 6: Water Environment for the assessment of potential impacts associated with aquifers.

Coastal and estuarine habitats are considered to be of medium value. The magnitude of habitat degradation on coastal and estuarine habitats is considered to be medium during construction and operation. Therefore prior to mitigation the impact is assessed to be of moderate significance.

Intertidal Mudflats, Sandbanks and Sandy Beach Habitats The distribution of intertidal mudflats, sandbanks and sandy beaches will change in response to the dredging of the access channel and associated geomorphological changes. The impact of long term geomorphological changes was assessed in Chapter 7: Marine and Littoral Physical Environment as being of major significance for intertidal and sandy beach habitats. Changes in bathymetry caused by dredging and dredge disposal will affect the mudflats, sandbanks and beaches by altering the hydrodynamic regime and sediment supply to the coast. Part of the design of the channel is to minimise the dredging (both in volume and area). The approach channel will be a large deepening of the natural river and will extend approximately 30 km offshore, although with a progressively smaller dredge depth in the deeper areas. Modelling conducted for the Project indicates that changes to waves may result in erosion along the beaches on the shores of Ile Kakossa, and changes to the beaches at the Morebaya River mouth on Ile Kaback. The modification due to changes in the nearshore wave climate is not expected to significantly affect the cross-shore profile shape of beaches. In addition, the shipping channel is expected to cause drawdown of sediment in the Morebaya River estuary as the channel seeks to infill, which may affect the beaches and mudflats on both sides of the river. It is estimated that this may lead to an overall lowering of the area around the channel by a few millimetres per year to a few centimetres per year. In the long-term, this subsidence effect is expected to adversely affect the beaches over several kilometres at both sides of the channel. Sedimentation of the dredged areas will continue over time, however, the approach channel will be maintained at depth through additional maintenance dredging and the effects on the nearby habitats will be long term. In addition, sandy material trapped in the dredged areas will be removed by dredging and taken out of the local sediment budget at the river mouth (2). This will lead to a sediment deficit for maintenance of some of the sandy features of the estuary mouth, and some of the sandbanks on either side of the channel may therefore be reduced in height and extent. The deficit of sand trapped in the dredged areas and the changed hydrodynamics may exacerbate sandbank migration and also lead to increased intrusion or drawdown of these features into the channel. Muddy material will also be removed by dredging but the muddy sediments depositing in the dredged areas will originate from the entire shallow water area at the site and not only from the river, which may only have a small contribution to the mud accumulations in the channel on an annual basis. Beaches will be more sensitive to the changed wave and flow conditions and beach erosion close to the river mouth (within 5 km of the river mouth) may occur on the either or both the north and south sides of the river as the shoreline adjusts itself to the changing conditions. Mudflats and sandbanks are considered to be of medium value as they support species specifically adapted to the habitat type (eg some bird species) and have a relatively rich biodiversity. Sandy beaches are also of

(1) Seasonal effects are not included in this analysis. (2) Internal Project Engineering Studies (2012).


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medium value as they are locally rare and may support turtle breeding, although are not considered to be important nesting sites. The magnitude of impacts from geomorphological changes to intertidal mudflats, sandbanks and sandy beaches is considered medium over both construction and operation since a significant proportion of the habitat will be affected so that its function is reduced or lost, although the long-term viability of the habitat type and species dependent on it is not threatened.

Sandbanks, mudflats and sandy beaches are considered to be medium value. The magnitude of impact due to geomorphological changes to these habitats is medium. Therefore prior to mitigation the impact is assessed to be of moderate significance during both construction and operation.

Mangrove Habitats Mangrove habitats may be lost or degraded through: indirect loss of habitat through the long term geomorphological changes; and loss of hydraulic connectivity. Impacts on the mangrove shoreline were assessed in Chapter 7: Marine and Littoral Physical Environment. Changes to the hydrodynamics may have consequences for the river bank at the port site and further downstream, which may affect the mangroves. Impacts on mangroves along the coast may also occur due to drawdown of the foreshore and altered erosion / accretion patterns. As described above, modelling conducted for the Project has shown that changes in waves and sediment supply may affect the coastline, which may lead to loss of mangrove habitat along the shores of Ile Kakossa and Ile Kaback. Increased areas of erosion and deposition will cause loss of mangrove habitat over an extended period of time. For example, excessive deposition induced by the presence of the port can potentially bury mangrove breathing roots and cause the mangroves to die back. Given that changes to bathymetry are planned for the life time of the Project the effects are considered long-term, beginning during construction and continue throughout operation. Habitat degradation and ultimately habitat loss is also likely due to reduction of hydraulic connectivity of upstream waterways (eg mangrove creeks) as a result of reduced or halted water exchange. The extent of loss of mangrove habitat will depend on the location of any waterway crossings and the extent of the obstruction in water flow (complete blockage or reduced tidal exchange). The approach jetty to the export wharf is not expected to block a small tidal creek and so no additional mangrove is expected to be lost through loss of hydraulic connectivity due to the port. Impacts from the MOF alone are assessed under a separate SEIA, as discussed in Section 13.2.2. As described previously, mangrove habitat is considered to be of medium biodiversity value. The magnitude of effect from indirect mangrove habitat loss is considered medium during construction as potentially a proportion of the habitat may be affected and the function reduced; however, the long term viability of the habitat in the wider area will not be threatened. Port operations are not expected to contribute to on-going indirect loss of mangrove habitat.

Mangrove habitat is a medium value habitat. The magnitude of impacts due to indirect loss and degradation is considered medium. Therefore the impact is assessed to be of moderate significance during construction, prior to mitigation.

13.4.8.2 Indirect Habitat Loss and Degradation of Habitats: Impacts on Fauna Marine Mammals Indirect loss of mangrove at the port location and the nearby coastal areas may cause displacement of local manatees to less suitable habitat and alter the distribution and abundance of the species in the local area.


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Given the wide availability of mangrove habitat in Guinea it is possible that displaced manatees would be able to find alternative foraging areas nearby. Given the likely seasonal movements by manatees (see Section 13.3.6.2) and the presence of suitable habitat in the vicinity of the port, a conservative approach to assessment is adopted whereby manatees are assumed to occur within the Project study area. Indirect loss of mangroves may therefore cause displacement of manatees to less suitable habitat nearby, which may affect a local manatee group since they often rest together in loose, small groups of two to six individuals. The West African manatee is a medium value species as it is listed as Vulnerable on the IUCN Red List. The magnitude of indirect habitat loss on manatees is considered medium since displacement may bring about a change in local abundance.

The West African manatee is considered to be medium value species. The magnitude of indirect loss of mangrove habitat on the West African manatee is considered medium. Therefore the impact is assessed as being of moderate significance prior to mitigation.

Marine Birds Littoral habitats, including mudflats, sandbanks, sandy beaches and mangroves, provide important nesting and feeding grounds for many species of birds. The mudflats in the vicinity of port are especially important feeding areas for wading birds. Indirect loss of littoral habitat and associated benthic communities due to geomorphological changes and altered erosion / accretion of beaches may reduce the available feeding and nesting grounds and cause displacement of individuals to other areas. However, bird species found in the study area are not restricted to the immediate vicinity of the port and other similar habitats are available in the region. The Eurasian curlew is a medium value species as it is listed as Near Threatened on the IUCN Red List. Other marine bird species likely to be found in the port study area are of low value as they are not protected or listed and are widespread and/or abundant. The magnitude of indirect habitat loss and habitat degradation on birds is considered small during construction and operation as only a small proportion of the overall populations may be affected but the populations themselves will not be impacted.

Marine bird species in the study area are considered to be of low value, except the Eurasian curlew which is medium value. The magnitude of impact of indirect habitat loss and habitat degradation during construction and operation is considered to be small. Therefore the impact is assessed as not significant for low value birds and of minor significance for the Eurasian curlew prior to mitigation.

Sea Turtles Sea turtles may be affected by geomorphological changes resulting from dredging activities throughout the life of the Project, especially alteration of natural erosion / accretion of sandy beaches, which may be used as nesting beaches. However, current evidence suggests that the sandy beaches in the vicinity of the port are not significant for turtle nesting. Hawksbill, Leatherback, Loggerhead and Green sea turtles are considered to be of high value due to their IUCN status (Critically Endangered and Endangered). The Olive Ridley sea turtle is medium value as it is listed as Vulnerable on the IUCN Red List. However, only the hawksbill, green and olive turtles are likely to nest on the beaches. The magnitude of indirect habitat loss and habitat degradation on sea turtles is small as only a few individuals may be affected, given that turtles are only reported infrequently in low numbers, and the population is not expected to be impacted.


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Hawksbill, Leatherback, Loggerhead and Green sea turtles are considered to be of high value and the Olive Ridley sea turtle is medium value in terms of their IUCN status. The magnitude of indirect habitat loss and habitat degradation on sea turtles is small during construction and operation. The impact is therefore assessed as being of minor significance for the Olive Ridley sea turtle and moderate significance for Hawksbill, Leatherback, Loggerhead and Green sea turtles prior to mitigation.

Fish Fish may be affected by degradation of intertidal mudflats, sandbanks and mangroves, which will likely begin during construction and continue throughout the operational period. These habitats have importance for a variety of fish species for feeding and breeding. Mangroves in particular play an important role as nursery areas for juvenile fish and supply a great deal of the organic matter that provides food sources within the coastal environment of Guinea. Losses of these functions in mangrove and other littoral habitats could result in reduced survival of juvenile fish and availability of food. This may alter the abundance and distribution of fish species as they will have to find foraging areas elsewhere. Although degradation of intertidal mudflats, sandbanks and mangroves is likely, these changes will develop over a time frame allowing biological communities to react and respond to these changes (eg many species will find alternative nearby habitat). Changes in habitat type will also occur due to changes in the geomorphological regime. For example there may be a loss in intertidal mudflats but gain in subtidal benthic habitat, which will also change the distribution of species. Changes in salinity gradients within the estuary and river could affect the distribution of local fish species as increased salinity within the estuary may allow coastal species to move further into the estuary. However, given that salinity within the estuary and coastal waters naturally changes with the seasons (eg estuarine salinity changes from 30 to 35 ppt during the dry season to 5 to 18 ppt during the wet season), the local fish species are likely to be adapted to changes in salinity, although the salinity changes resulting from the port dredging activities will be permanent rather than seasonal. Fish species within the study area are of low, medium or high biodiversity value depending on their conservation status. High value species are those listed as Critically Endangered or Endangered on the IUCN Red List. Medium value species are those listed as Vulnerable, Near Threatened, or Data Deficient on the IUCN Red List. Low value species are those listed as Least Concern on the IUCN Red List. A selection of high and medium value fish species is presented in Table 13.10. The magnitude of impact of indirect habitat loss and habitat degradation on fish is considered to be medium during construction and operation as only a small proportion of the fish populations will be affected but the populations themselves will not be impacted.

Fish species within the study area are of low, medium or high value depending on their conservation status. The magnitude of impact of indirect habitat loss and habitat degradation on fish is considered to be medium during construction and operation. Impacts are therefore assessed as being of major significance for high value species, moderate significance for medium value species and minor significance for low value species prior to mitigation.

13.4.9 Indirect Impacts: Invasive Alien Species 13.4.9.1 Overview Invasive species can be introduced into areas through ballast water exchange, infected equipment and hull fouling. Ballast water is carried by ships to provide stability and adjust a vessel's trim for optimal steering and propulsion. The use of ballast water varies among vessel types and with cargo and sea conditions. Ballast water often originates from ports and other coastal regions that may host rich planktonic assemblages. As part of normal ship operations, ballast water can be discharged in ports, along coastlines


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or at sea, so that a diverse mix of organisms are transported and released around the world. Ballast water is one of the most important vectors for the transfer of marine species throughout the world. Organisms such as barnacles, mussels, sponges, algae and sea squirts attach themselves to the hulls of ships. This is commonly referred to as biofouling. The attached organisms are then carried by the vessel from one port to the next, thus entering new bioregions. Invasions can occur when fouling organisms come in contact with structures in a new port or release their larvae into its waters. Under the right conditions, these invaders may establish themselves in the new port and spread to nearby areas within that bioregion. Organisms may also travel between bioregions attached to marine equipment, such as dredging equipment or in sediment carried by a dredger or dredging equipment or on barges. 13.4.9.2 Invasive and Alien Species: Impacts on Habitats and Species Invasive alien species can cause impacts at the ecosystem level, which includes all habitats and species. The introduction on invasive alien species can threaten ecosystem diversity and abundance (1). They can affect ecosystem processes by upsetting the natural balance, which can lower the ecosystem’s ability to cope with additional pressures and impacts and result in a lower biodiversity and an unhealthy ecosystem. Impacts to biodiversity from invasive or alien species may include (2): loss of biodiversity through:

changes in predator-prey interactions; decreased habitat availability for native species; additional competition for food and space; direct damage to native habitats; new parasites and disease; smothering and overgrowth; and hybridisation, causing genetic dilution.

changes to ecosystem function and community structure;

changes to nutrient cycles; and

decreased water quality. Given the number of vessel movements to and from the port over the construction and operation periods there is a high risk of alien species being present in ballast waters or on hulls. As part of the Project design the IMO Guidelines for the Control and Management of Ships’ Ballast Water to Minimise the Transfer of Harmful Aquatic Organisms and Pathogens and the IMO International Convention on the Control of Anti-fouling systems on ships (AFS) will be applied. Not all alien species will be able to establish viable populations and become invasive. However, this risk is still present and the consequences on biodiversity can be severe. Habitats and species are rated as high, medium or low value depending on their qualifying criteria (see Section 13.3). The magnitude of impact during both construction and operation is considered large as a sufficient proportion of the habitat may be affected so that the viability / function of the entire habitat is reduced and the long-term viability of the habitat and the species dependent on it are threatened. A long term decline in abundance and / or change in distribution of species may also be observed.

(1) IUCN. About Marine Invasive Species. Available at

http://www.iucn.org/about/work/programmes/marine/marine_our_work/marine_invasives/seychelles/about_marine_invasive_species/ -

last accessed May 2012. (2) IUCN. Marine Menace Alien invasive species in the marine environment. Available at http://www.cbd.int/invasive/doc/marine-menace-iucn-en.pdf - last accessed May 2012.


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Habitats and species are rated as high, medium or low value depending on their qualifying criteria. The magnitude of impacts from invasive and alien species will be large. The impact is therefore assessed as being of critical significance for high value species, major significance for medium value habitats and species and moderate significance for low value habitats and species prior to mitigation.

13.4.10 Indirect Impacts: Induced Access 13.4.10.1 Overview Induced access occurs when a development facilitates human access to remote areas that previously have been subject to low levels of disturbance and limited pressure on natural resources. The scale and nature of the impacts that can arise after are variable and dependent on a range of factors such as: the value of the habitats and taxa in the area; the scale of the in-migration which ensues as a result of families of Project employees moving to the

area and of opportunistic migration; the extent to which workers and the Project make purchases in the local area; and considerations such as the cultural norms prevailing in the area. Opportunistic in-migrants may clear land for homes and agriculture and rely heavily on the natural resource base. The opportunistic in-migration that the construction of the port may induce is not easy to predict and will not be within control of the Project. The impacts will be felt from early in the construction phase, and throughout it. As the port will have a permanent on-site operational workforce the informal in-migrant population is likely to persist as long as the prospect of employment continues. Any decline in the in-migrant population as the port moves into the operational phase is uncertain and cannot be predicted, so for the purposes of the assessment it has been assumed that once settled in an area an in-migrant population will remain. In-migration is discussed in detail in Chapter 19: In-Migration but considered below in terms of impacts on biodiversity. This assessment considers the increase in exploitation due to the project and not the existing anthropogenic threat level. 13.4.10.2 Induced Access: Impacts on Habitats Mangrove habitat is at risk from land clearance by an increased number of people living in the study area and those displaced by the Project. Increased access to remote areas due to the presence of project roads and access routes will also increase pressure on mangroves. Mangroves will be targeted for land clearance for agriculture purposes and also as a source of timber. The threat from induced access and in-migration on mangroves will begin during construction and continue through operation. The mangroves in the port study area are relatively widespread but are already subject to modification by humans, with large areas of land cleared for rice fields. As such they represent lower quality habitats when compared to less degraded areas elsewhere in the country. Areas of less disturbed mangrove habitat within the port study area are small, few in number, and fragmented, and are considered likely to be subject to further pressures. For this reason a conservative approach has been used to assessing the impact of induced access. As described previously mangrove habitat is considered to be of medium value. Taking into account the unknown scale of in-migration to the port area that the long term viability of the habitat may be threatened the magnitude of in-migration on mangrove habitat is considered large.


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Mangrove habitat is considered to be medium value. The magnitude of impacts from induced access on mangrove habitat will be large. The impact is therefore assessed as being of major significance prior to mitigation.

13.4.10.3 Induced Access: Impacts on Fauna In-migration will increase pressure on already overexploited fisheries due to the increased number of people living in the study area. This will in particular be the case for fish species of commercial and artisanal fishing interest. Over-fishing may threaten fish population numbers and lead to a reduction in abundance and distribution of fish species in the port study area. Several IUCN Endangered and Critically Endangered benthic elasmobranch species are known to be particularly vulnerable to targeted fishing, and are also taken as bycatch. However, these species are not reported to occur frequently or in high numbers in the port study area. Many of the fish species targeted will be of medium or low value. Species not targeted by fishing will also be affected through bycatch. In addition, sea turtles (including their eggs) are also captured for food and in-migration may increase poaching of these species. Turtles are reported to occur infrequently in low numbers and those that do occur are often captured and eaten. The impact will begin during construction and continue throughout operation. Increased human and dog presence on the coast due to increased numbers of people living in the region may affect the nesting behaviour and success of turtles and the survival of incubating eggs and hatchlings as humans and dogs can potentially disturb nesting turtles, causing females to abort nesting attempts at all stages of the process, change their nesting beaches, delay egg laying and select poor nesting sites (1). Fish species within the study area are of low, medium or high value depending on their conservation status. See Section 13.3.6 for species within these categories. Taking into account the unknown scale of in-migration to the port area and that a decline in abundance of fish stocks may occur, the magnitude of impact on fish due to in-migration is considered large for species targeted by fisheries, which are generally medium and low value species. High value benthic elasmobranchs will be less impacted due to their frequency of occurrence and a result medium magnitude impacts may occur to these species. The impact is therefore assessed as being of major significance for species of high value (mainly the benthic elasmobranchs), major significance for species of medium value and moderate significance for species of low value. Hawksbill, Leatherback, Loggerhead and Green sea turtles are of high value and Olive Ridley sea turtles are of medium value. Taking into account the unknown scale of in-migration and the frequency of reported occurrence a medium magnitude impact may occur to these species.

Fish species are considered to be high, medium and low value depending on their IUCN status. Turtles are of high value, except for the Olive Ridley sea turtle, which is of medium value. The magnitude of impacts from induced access is large, except for high value benthic elasmobranchs and all turtles where a medium magnitude impact may occur. The impact is therefore assessed as being of major significance for species of high value (mainly benthic elasmobranchs and most turtle species), major significance for species of medium value and moderate significance for species of low value prior to mitigation.

13.4.11 Indirect Impacts: Waste and Marine Litter Waste is generated throughout the construction and operation phases. Any litter or waste introduced into the marine, estuarine and littoral environment has the potential to harm marine fauna through ingestion or trapping or entanglement in litter. Discarded food wastes will also attract vermin and gregarious birds to the local area, potentially displacing local species. The consequences of the port in terms of waste production are considered in more detail in Chapter 11: Resources and Non-Mineral Waste Management. It is expected

(1) National Research Council (U.S.). Committee on Sea Turtle Conservation (1990). Decline of the sea turtles: causes and prevention. National Academies Press.


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that a large amount of waste will be generated, especially during construction and without appropriate management waste could be introduced to the marine environment. Habitats and species are rated as high, medium or low value (see Section 13.3). The magnitude of impact is considered medium as waste could affect significant proportions of several of the habitats and species in the area, although it would be unlikely to affect their long-term viability.

The magnitude of impacts from waste will be medium. The significance of this impact will therefore vary from being of major significance for high value species such as turtles and manatees to being of minor significance for low value species and habitats, such as offshore pelagic habitats and benthic organisms prior to mitigation.

13.4.12 Non-Routine Events - Spills 13.4.12.1 Overview Use of vessels and machinery presents the potential for spillages of fuels, and other potentially polluting substances. It is assumed that all bulk fuel and other hazardous materials storage areas will be designed to contain spills through appropriate impermeable bases, bunding capacities and maintenance as required and as such no routine pollution from these major sources would be expected. However, it is possible that small amounts of hydrocarbons may at some point enter the marine and littoral environment, either directly (eg during fuel transfer) or through run off from hardstanding areas. Large spills, however, are also possible and may occur due to accidents such as collision of vessels, grounding of iron ore carriers, extreme weather events, poor maintenance and operational / navigational errors. In the event of an accidental release from a fuel tanker its complete cargo may be discharged, which would be approximately 25 000-45 000 DWT of fuel for a midsize tanker. A large spill involving a fuel tanker or iron ore carrier will affect a large area of marine environment and coastal habitats with secondary impacts on a large range of fauna and flora that depend on the coastal area and marine waters. The impact of non-routine events has been assessed in terms of the risk. This is defined as the product of the consequence of the event and the probability of occurrence (risk = probability x consequence). Risk rating refers to magnitude if event does happen, it does not mean that there is a high risk of the event occurring. The prediction of magnitude takes into account the risk of the impact; that is its probability of occurrence as well as the severity of consequences. 13.4.12.2 Non-Routine Spills: Impacts on Habitats and Species Impacts on water and sediment quality from spillage and pollution events were assessed in Chapter 7: Marine and Littoral Physical Environment to be of minor significance for small spills of hydrocarbons and major significance for large spills. Table 13.14 below presents an assessment of both large and small spills on biodiversity features in the port study area.


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Table 13.14 Impact Magnitude Analysis of Spills on Sensitive Receptors

Habitat / Species Group

Oil Spill Scenarios Impact and Recovery [1]

Magnitude of Impact

Small Spill

Large Spill

Offshore pelagic and benthic habitat

Large spills due to vessel groundings and / or collisions.

Most oils float on the sea surface and are spread under the influence of wind and currents. Low viscosity oils will disperse within the top few metres of the water column where they are rapidly diluted, especially in the presence of breaking waves. The impact on the lower water column is considered less although there is the possibility that the oil may sink and affect the benthic habitat. Therefore the impact on the habitat is considered short term.

Small Medium

Coastal and Estuarine waters

Large spills in the port due to vessel grounding, collision, other release.

Small spills in the port during fuel transfer operations.

Oil can become mixed into the water column by strong wave action. Tidal flushing will rapidly dilute the oil in water and generally keep concentrations below harmful levels, although refined products that have dispersed into the water may lead to high concentrations of the toxic components at the seabed. Therefore the impact on the habitat is considered short term.

Medium Large


Large spills in the port due to vessel grounding, collision, other release.

Small spills in the port during fuel transfer operations.

Fine sands and muds are not as readily impacted as other substrates but oil can become incorporated by flocculation with sediment stirred up by wave activity or penetration through worm burrows. Pollutants that do penetrate can persist for many years. Therefore the impact is considered long term.

Small Medium

Sandy beach Large spills in the port due to vessel grounding, collision, other release.

Small spills at the port during fuel transfer operations.

Sandy shores are most resilient to spills due to the scouring effects of wave action and tidal currents, which allows rapid self-cleaning to take place. Therefore the impact is likely to be short term.

Small Large

Mangroves Large spills in the port from vessel grounding, collision, other release.

Small spills at the port during fuel transfer.

Oil enters mangroves at high tide and sticks to the roots and sediments as the tide goes out. Mangroves are particularly sensitive and vulnerable to oil spills due to smothering of breathing roots by oil. Large areas of mangrove can be completely destroyed by oil spills. Therefore the impact is long term as mangrove recovery is slow.

Medium Large


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Magnitude of Impact

Small Spill

Large Spill

Cetaceans Large spills from vessel groundings and or collisions in the offshore pelagic environment or in coastal and estuarine waters.


Cetaceans are vulnerable to impacts from floating oil when they surface to breathe. Oil can also have toxic effects, damage organs through ingestion, damage airways and cause behavioural changes.

The port study area is not an important habitat for cetaceans as they have extensive ranges and are only likely to occur inshore frequently. Therefore impacts on the species from direct interaction with oil is short term as oil will rapidly degrade.

Small Medium

West African manatee

Large spills in the port from vessel grounding, collision, other release.


Manatees are considered less sensitive (compared to turtles and birds) to any impacts resulting from an oil spill as they will generally avoid the area affected.

No manatees are reported at the port location, although given the habitat types and their occurrence further upstream they may occur occasionally. Therefore impacts to the species is short term, although impacts to their mangrove habitat may be long term (see above).

Small Medium

Birds Large spills at the port from vessel grounding, collision, other release.


May affect the coastal, intertidal and mangrove habitats

Direct mortality of birds in the event of an oil spill is often the most widely perceived risk. Impacts to birds are more pronounced in coastal waters than offshore. Birds are affected by oil pollution by impacts to their plumage, toxic effects and habitat destruction. A small spill in an area with a large number of birds can be as harmful as a large spill when few birds are present.

Intertidal areas and mangroves are important bird feeding and breeding areas and impacts to these habitats are therefore short and long term, respectively. The coast of Guinea supports large numbers of migrant birds and so many birds could be affected.

Medium Large

Turtles Large spills at the port from vessel grounding, collision, other release.


May affect the coastal and offshore habitats and sandy beaches.

Floating oil may be a threat to turtles, which are particularly vulnerable during the nesting season but are sensitive to the effects of oil spills at all life stages. Direct impacts may result in death or egg mortality and developmental defects. Indirect impacts may result from loss of smell sensors causing behavioural effects, contamination of food supply and reduction in available food levels.

Although turtles may occur in the port study area no important nesting sites are present based on surveys conducted for the project.

Medium Large


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Magnitude of Impact

Small Spill

Large Spill

Fish Large spills at the port from vessel grounding, collision, other release.


May affect the coastal and offshore pelagic and benthic habitats.

Fish species are most vulnerable to the effects of oil spill in the intertidal zone or where water is very shallow. Fish eggs and fish larvae are relatively sensitive to low oil concentrations, however, adults are more resilient and actively avoid oil. Mass mortalities are rare but stock depletion may occur in the short term.

The port study area is utilised by many fish species, although they are not limited to the study area and other similar habitats are available nearby. Therefore the impact on fish will be short term.

Medium Large

Benthic invertebrates

Large spills at the port from vessel grounding, collision, other release.


May affect the coastal and offshore pelagic and benthic habitats.

There is the possibility that oil may sink and affect the benthic habitat, including the benthos. No high value benthos occurs in the port study area. Therefore te impact is short term due to the natural degradation of the oil.

Small Medium

Note: [1] Most of the information above is from the following source: ITOPF (2011); Effects of oil pollution in the marine environment. Technical information paper 13.


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Habitats and species are rated as high, medium or low value (see Section 13.3). The magnitude of impact is assessed above in Table 13.14 and varies with habitat, species and type of spill.

Habitats and species are rated as high, medium or low value (see Section 13.3). The magnitude of impact is assessed above in Table 13.14 and varies with habitat, species and type of spill. The significance of this impact will therefore vary from being of critical for large magnitude impacts on high value receptors to not significant for small magnitude impacts on low value receptors prior to mitigation.

13.5 Mitigation Measures and Residual Impacts 13.5.1 Introduction This section describes the measures to which the Project has committed to mitigate the impacts of the Simandou Port on biodiversity as assessed in Section 13.4. In addition, where further studies are identified to confirm or inform better the assessment, these potential studies are described. Finally where monitoring has been identified to determine whether mitigation is operating effectively these monitoring are outlined. Mitigation measures are described in this SEIA and listed in Volume V Social and Environmental Management Plan. Mitigation measures relevant to the marine physical environment are considered in Chapter 7: Marine and Littoral Physical Environment, terrestrial and freshwater biodiversity are considered in Chapter 12: Terrestrial Biodiversity, surface and ground water are considered in Chapter 6: Water Environment and terrestrial soils are considered in Chapter 5: Geology, Soils and Mineral Waste. The impact assessment has included the application of relevant international, national and Rio Tinto guidelines and policies, where relevant. Where significant impacts have been identified for marine and littoral habitats and species, further mitigation measures are required. Residual impacts that will remain after additional mitigation is taken into account are also reported. 13.5.2 Mitigation of Direct Loss of Habitat This section refers to mitigation for the direct loss of habitat and the related impacts on associated species. Mitigation measures as described below will be implemented to reduce impacts as far as reasonably practicable. Facilities in coastal areas will be located with sufficient setbacks to minimise impacts to littoral habitats, such as mangroves. In addition, a Project-specific Mangrove Management Plan (MMP) will be developed and implemented to reduce impacts to mangroves. The MMP will highlight the potential direct and indirect impacts that may occur to mangroves and give details of the mitigation, management and monitoring that will be implemented. Mitigation measures in the MMP will include: mangrove shoreline and inland mangrove will be left intact if possible, without compromising

navigational safety or construction access; and measures will be implemented to ensure that cleared areas (or areas with other mangrove loss due to

the port) are replanted with mangrove seedlings as soon as possible, if suitable for rehabilitation due to the new hydrodynamic regime and continued access requirements.

A Dredging Spoil Disposal Management Plan (DSDMP) will be designed for the port and implemented throughout construction and operation. The purpose of the DSDMP is to set out the environmental mitigation and monitoring framework that will be implemented to ensure that any environmental impacts are minimised to as low as reasonably practicable. The DSDMP will spatially define the different sensitive marine biodiversity attributes within the port study area and contain measures covering all aspects of the dredging operations. Measures of relevance to the marine and littoral physical environment are considered in Chapter 7: Marine and Littoral Physical Environment but are also included here for completeness as they are


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also relevant to marine and littoral biodiversity. Mitigation and monitoring measures to be included in the DSDMP include: the dredging contractor will be required to provide modern fully equipped dredger(s) that meet the

standards expected of best practice dredging, including installation of technology normally associated with modern dredgers, in line with Rio Tinto guidelines;

the type and size of dredger should also be selected based on the appropriate dredging method for the

material being dredged and the characteristics of the dredging areas; the dredgers will have monitoring and automation systems to improve dredging accuracy and efficiency;

and dredging and sediment disposal will only occur within the specified limits (both in area and depth)

through the use of appropriate positioning technology. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures discussed above, the residual impacts of direct habitat loss in the study area will be as follows. 13.5.2.1 Offshore Benthic Habitats Pre-mitigation impacts related to direct loss of offshore benthic habitats were classified as minor significance and the mitigation measures associated with limiting the dredge areas and dredged volumes to necessary levels will not significantly change the level of impact; therefore residual impacts remain as minor significance. 13.5.2.2 Coastal and Estuarine Habitats Pre-mitigation impacts related to direct loss of coastal and estuarine habitats were classified as moderate significance and the mitigation measures associated with limiting the dredge areas and dredged volumes to necessary levels will not significantly change the level of impact; therefore residual impacts remain as moderate significance. 13.5.2.3 Mudflat and Sandbank Habitats Pre-mitigation impacts related to direct loss of mudflat and sandbank habitats were classified as minor significance and the mitigation measures associated with limiting the dredge areas and dredged volumes to necessary levels will not significantly change the level of impact; therefore residual impacts remain as minor significance. 13.5.2.4 Mangrove Habitats Pre-mitigation impacts related to direct loss of mangrove habitats were classified as moderate significance and the mitigation measures associated with limiting the loss of mangroves and regenerating mangroves in degraded areas, where possible, will reduce the level of impact; therefore residual impacts are classified as minor significance. 13.5.2.5 Marine Mammals Pre-mitigation impacts on the West African Manatee through direct loss of habitat were classified as moderate significance and the mitigation measures associated with limiting the loss of mangroves and regenerating mangroves in degraded areas, where possible, will reduce the level of impact; therefore residual impacts are classified as minor significance.


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13.5.2.6 Marine Birds Pre-mitigation impacts on the marine birds through direct loss of habitat were classified as minor significance for the Eurasian curlew. The mitigation measures associated with limiting the dredge areas and dredged volumes to necessary levels as well as limiting the loss of mangroves and regenerating mangroves in degraded areas will not significantly change the level of impact; therefore residual impacts remain as minor significance for the Eurasian curlew. 13.5.2.7 Fish Pre-mitigation impacts on fish species through direct loss of habitat were classified as moderate significance for high value species and minor significance for medium value species. The mitigation measures associated with limiting the dredge areas and dredged volumes to necessary levels as well as limiting the loss of mangroves and regenerating mangroves in degraded areas will not significantly change the level of impact; therefore residual impacts remain as moderate significance for high value fish species and minor significance for medium value fish species. 13.5.3 Mitigation of Mortality and Injury to Animals The following measures will be implemented to mitigate for the impact of mortality and injury to animals due to collisions with vessels or entrainment in the draghead: inductions for all dredge vessel crew to cover awareness and procedures to be undertaken to minimise

disturbance to marine fauna;

dredge suction pumps are not to be operated until within 0.5 m of the seabed, or as close as possible to the seabed to avoid fish entrainment;

dredge pumps will be turned off as soon as possible after the drag head clears the seabed; turtle exclusion devices (tickler chains) will be fitted to dredgers to reduce the risk of entrainment of

turtles (and benthic fish);

turtle exclusion devices (tickler chains) will be inspected regularly for damage to ensure effective use and if damage to the devices occurs frequently their use will be re-evaluated;

vessel operators and crews will maintain a vigilant watch for marine mammals and sea turtles and

where feasible and safe to do so slow down or stop their vessel to avoid striking individuals; all vessels will operate in line with pilotage speed restrictions, for example at ‘no wake’ speeds while in

the vicinity of manatee habitat and while in water depths where the draft of the vessel provides less than a 1.5 m clearance from the seabed / riverbed;

all personnel associated with the port will be instructed about the likely presence of manatees / turtles /

cetaceans and the need to adhere to speed zones to avoid collisions with wildlife; vessels within shipping channel and en route to and from dredge disposal sites will maintain speeds of

less than 14 knots to reduce the likelihood of collisions with cetaceans; when sea turtles and small cetaceans (eg dolphins) are sighted, vessels will maintain a distance of at

least 50 m, whenever possible; where feasible and safe to do so dredging operations will be shut down if a manatee / turtle / cetacean is

sighted within 50 m of the operation. Activities will not resume until the animal(s) has moved at least 50 m away from the operation or until an agreed period has passed without sighting the animal within the 50 m safety zone. Animals must not be harassed or herded away;


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all Project vessels will follow deep water routes wherever possible; and vessel crews or independent observers on vessels will report sightings of any injured or dead marine

mammals, turtles or manatees immediately, regardless of whether the injury or death is caused by their vessel.

Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from direct mortality of fauna in the study area is considered to be the following. 13.5.3.1 Marine Mammals Pre-mitigation impacts on the marine mammals through direct mortality due to collisions and / or entrainment were classified as being of minor significance for the Atlantic humpback dolphin and other medium value species and of moderate significance for high value species, including the West African manatee. The mitigation measures associated with vessel crew awareness of the presence of marine mammals, halting in-water work when marine mammals are in close proximity and restricted vessel speeds will change the level of impact; therefore residual impacts reduce to not significant for the Atlantic humpback dolphin and other medium value species and of minor significance for high value species, including the West African manatee. 13.5.3.2 Marine Reptiles Pre-mitigation impacts on the marine reptiles through direct mortality due to collisions and / or entrainment were classified as minor significance for the Olive Ridley sea turtle and moderate significance for Hawksbill, Leatherback, Loggerhead and Green turtles. The mitigation measures associated with turtle exclusion devices on dragheads, ensuring dragheads are on or near the seabed before starting suction pumps, vessel crew awareness of the presence of marine reptiles, halting in-water work when marine reptiles are in close proximity and restricted vessel speeds will change the level of impact; therefore residual impacts reduce to not significant for Olive Ridley sea turtles and minor significance for Hawksbill, Leatherback, Loggerhead and Green turtles. 13.5.3.3 Fish Pre-mitigation impacts on the fish through direct mortality due to entrainment were classified as being of minor significance for medium value fish species and moderate significance for high value fish species (eg elasmobranchs). Installation of exclusion devices, such as ticklers, on dredgeheads and ensuring dredgeheads are on or near the seabed before starting suction pumps will change the level of impact; therefore residual impacts reduce to not significant for medium value fish species and minor significance for high value fish species (eg elasmobranchs). 13.5.4 Mitigation of Noise Underwater noise cannot be totally avoided due to the range of in-water activities proposed during construction of the port (ie piling, dredging and vessel movements). The duration, frequency and / or volume of noise can be reduced through appropriate mitigation during in-water operations. Impacts due to disturbance from underwater and airborne noise will be mitigated by implementing the following measures: piling should preferably commence during daylight hours which allow a pre soft start observation period; the soft start period should commence only after a 30 minute pre-piling search of the observation zone

of 500m from the source; soft start procedures for piling of not less than 20 minutes will be used to slowly increase noise to enable

marine mammals / reptiles / fish to move away from the noise source prior to commencement of full operational activities;


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piling should not commence if marine mammals are detected in the mitigation zone or for 30 minutes

after the last observation;

if marine mammals (including manatees) or turtles are observed in the 500 m observation zone during soft start where ever possible piling should cease and in all cases power should not increase until the animal leaves the observation zone and there is no further observation for 20 minutes;

animals must not be harassed or herded away;

if there is a break of greater than 10 minutes in piling activity then the soft start proceedures should be

repteated;

all equipment and vessels will undergo regular maintenance to provide optimal performance; and monitoring of Peak Sound Pressure Levels (SPL) during pile driving to ensure levels do not exceed the

180 dB re 1 μPa peak threshold for harm to marine mammals. If SPL exceed acceptable limits, further methods to reduce the sound pressure levels will be employed, such as use of a noise reduction device in the form of a shroud or physical screen around the anvil, pile sleeves and pile caps.

Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from underwater and air borne noise in the study area is considered to be the following. 13.5.4.1 Marine Mammals Pre-mitigation impacts on the marine mammals through underwater noise during port construction were classified as being of minor significance for the Atlantic humpback dolphin and other medium value species and of moderate significance for high value species, including the West African manatee. The mitigation measures associated with management of in-water operations to reduce noise and / or to limit possible impacts from piling / dredging will change the level of impact; therefore residual impacts reduce to not significant for the Atlantic humpback dolphin and other medium value species and of minor significance for high value species, including the West African manatee. 13.5.4.2 Marine Birds Pre-mitigation impacts on the marine birds through airborne noise during port construction were classified as minor significance for the Eurasian curlew. The mitigation measures associated with management of in-water operations to reduce noise and / or to limit possible impacts from piling / dredging are not likely to change the level of impact; therefore residual impacts remain as minor significance for the Eurasian curlew. 13.5.4.3 Fish Pre-mitigation impacts on the fish through underwater noise during port construction were classified as being of minor significance for low value species, moderate significance for medium value species and major significance for high value species (eg elasmobranchs). Pre-mitigation impacts on the fish through underwater noise during port operation were classified as being of moderate significance for high value species and minor significance for medium value species. The mitigation measures associated with associated with management of in-water operations to reduce noise and / or to limit possible impacts from piling / dredging will change the level of impact; therefore residual impacts reduce to not significant for low value species, minor significance for medium value fish species and moderate significance for high value fish species (eg elasmobranchs) during construction and not significant for medium value species and minor significance for high value fish species during operation.


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13.5.5 Mitigation of Altered Water Quality Mitigation measures for impacts on water and sediment quality are presented in Chapter 7: Marine and Littoral Physical Environment. These are repeated below together with additional measures relevant to biodiversity. The principal mitigation measures associated with impacts on water and sediment quality are the application of relevant legislation regarding discharges and use of the best available technology and best environmental practice during dredging with regards to the dredge plume. A DSDMP will be designed for the port and implemented throughout construction and operation as appropriate. The DSDMP will contain measures covering all aspects of the dredging operations. Measures of relevance to the marine and littoral physical environment are considered in Chapter 7: Marine and Littoral Physical Environment but are also included here for completeness as they are also relevant to marine and littoral biodiversity. The dredging contractor will be required to provide modern fully equipped dredger(s) that meet the standards expected of best practice dredging, including installation of technology normally associated with modern dredgers, in line with Rio Tinto guidelines. The type and size of dredger should also be selected based on the appropriate dredging method for the material being dredged and the characteristics of the dredging areas. In addition, the dredgers will have monitoring and automation systems to improve dredging accuracy and efficiency. Dredging and sediment disposal will only occur within the specified limits (both in area and depth) through the use of appropriate positioning technology. The extent of altered water quality can be reduced (but not eliminated) through management of the dredging process, including the use of specific technology and dredging techniques; most are commonly used during major dredging programs worldwide. The following could be employed to reduce negative impacts to water quality: drag heads will be designed to improve suction efficiency; and ensuring equipment is properly calibrated. The full range of control measures for dredging including the Dredging and Spoil Disposal Management Plan are being developed and refined in line with on-going modelling and site characterisation. To avoid and reduce impacts on water quality, all treatment plants and discharge points will be regularly inspected, maintained and monitored for discharge quality to ensure the standards of discharge are being met. Contaminated runoff will be directed through sediment ponds to reduce the solids prior to discharge. As far as possible no work will be undertaken within 50 m of any surface waterbody, especially refuelling, maintenance and washdown of vehicles and equipment. Where this is not possible, additional measures will be taken to ensure that pollution of water resources does not occur. In addition, measures will be implemented to deal with acid sulphate soils in accordance with a Project-wide Acid Sulphate Soils Management Plan. An effective preventative maintenance programme will be established to ensure that all equipment that uses or contains any hazardous materials (including fuel and oil) is inspected regularly and maintained in good working order so avoid accidental leakages to marine and littoral environments. Inspection and maintenance records will be available for review. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from altered water quality in the study area is considered to be the following: 13.5.5.1 Fish Pre-mitigation impacts on the fish through altered water quality during port construction were classified as being of minor significance for low value species, moderate significance for medium value species and major significance for high value species (eg elasmobranchs). The mitigation measures associated with utilising best practice methods and management of the dredging process will lessen the level of impact; therefore residual impacts reduce to not significant for low value species, minor significance for medium value fish species and moderate significance for high value fish species (eg elasmobranchs).


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Pre-mitigation impacts on the fish through altered water quality during port operations were classified as being minor significance for medium value species and moderate significance for high value species (eg elasmobranchs). The mitigation measures associated with utilising best practice methods and management of the dredging process will lessen the level of impact; therefore residual impacts remain as not significant for medium value fish species and minor significance for high value fish species (eg elasmobranchs). 13.5.6 Mitigation of Altered Sediment Quality The extent of altered sediment quality can be reduced (but not eliminated) through management of the dredging process, including the use of specific technology and dredging techniques that are described in the Altered Water Quality section above. These mechanisms are commonly used during major dredging programs worldwide and could be employed to reduce negative impacts to sediment quality. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from altered sediment quality in the study area is considered to be the following. 13.5.6.1 Benthos Pre-mitigation impacts on the benthos through altered sediment quality during port construction were classified as being of minor significance. The mitigation measures associated with utilising best practice methods and management of the dredging process are not expected to significantly lessen the level and / or spatial extent of impact; therefore residual impacts remain as minor significance. 13.5.6.2 Fish Pre-mitigation impacts on the fish through altered sediment quality during port construction were classified as being of minor significance for low value species, moderate significance for medium value species and major significance for high value species (eg elasmobranchs). The mitigation measures associated with utilising best practice methods and management of the dredging process will lessen the level and / or spatial extent of impact; therefore residual impacts reduce to not significant for low value species, minor significance for medium value fish species and moderate significance for high value fish species (eg elasmobranchs). Pre-mitigation impacts on the fish through altered sediment quality during port operations were classified as being minor significance for medium value species and moderate significance for high value species (eg elasmobranchs). The mitigation measures associated with utilising best practice methods and management of the dredging process will lessen the level and / or spatial extent of impact; therefore residual impacts reduce to not significant for medium value fish species and minor significance for high value fish species (eg elasmobranchs). 13.5.7 Mitigation of Artificial Light Light disturbance will be mitigated during construction and operation through the use of low emission, directional lighting where possible. Where design of the infrastructure cannot prevent light spill from port facilities, screens will be established to prevent this impacting on beach areas. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from artificial light in the study area is considered to be the following. 13.5.7.1 Marine Birds Pre-mitigation impacts on the marine birds through artificial light during port construction and operation were classified as minor significance for the Eurasian curlew. The mitigation measures associated with directional


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lighting and / or light screens are likely to change the level of impact; therefore residual impacts reduce to not significant for the Eurasian curlew. 13.5.7.2 Marine Reptiles Pre-mitigation impacts on the marine reptiles through artificial light during port construction and operation were classified as minor significance for the Olive Ridley sea turtle and moderate significance for Hawksbill, Leatherback, Loggerhead and Green turtles. The mitigation measures associated with directional lighting and / or light screens will change the level of impact; therefore residual impacts reduce to not significant for Olive Ridley sea turtles and minor significance for Hawksbill, Leatherback, Loggerhead and Green turtles. 13.5.8 Mitigation of Indirect Habitat Loss and Habitat Degradation The deepening of the river, estuary and coastal waters for the approach channel cannot be mitigated since access for ore carriers to the port within the Morebaya River relies on establishing the deepwater channel. Therefore, the indirect effects of the channel development, such as the saltwater wedge that delivers saltwater further into the estuary than naturally occurs, the channelling of freshwater from the river out of the estuary and the altered erosion / accretion patterns along the coast adjacent to the Morebaya River, are likely to occur if the port development proceeds. Indirect loss of littoral habitats, especially beaches and mudflats, will be monitored by establishment of an on-going monitoring programme to examine potential changes in shape and area compared to a pre-dredge survey baseline, as described in Chapter 7: Marine and Littoral Physical Environment. The Project will conduct monitoring to assess potential impacts to the coastline. Monitoring will include: a monitoring programme will be designed based on modelling output and satellite imagery to assess

natural change alongside Project induced change; monitoring of the shape and alignment of the coastline using satellite imagery; and comparison of the coastline for each monitoring event with previous monitoring results to assess

coastline change. If coastal change attributed to the port development is observed during the monitoring studies, the Project will develop, regularly review and update a coastal management plan. In addition culverts will be used to maintain connectivity through waterways. Measures will be implemented to ensure that cleared areas (or areas with other mangrove loss due to the port) are replanted with mangrove seedlings as soon as possible, if suitable for rehabilitation due to the new hydrodynamic regime and continued access requirements. These measures will be implemented through the development of a Project-specific Mangrove Management Plan (MMP). Monitoring and auditing of potential environmental impacts that may arise from the dredging operation will include: pre-dredge monitoring and surveys:

pre-dredge water quality monitoring (turbidity, temperature, conductivity, salinity (including up the

river), dissolved oxygen, pH, light penetration, potential contaminants of concern, TSS and sedimentation);

infauna communities and particle size distribution at the sediment disposal grounds; bathymetry of the sediment disposal grounds; sediment particle size with distance from the dredging footprint; sensitive species health (eg mangroves); and sampling and analysis of soil material in risk areas for acid sulphate soils.

operational monitoring and surveys:


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water quality (as for pre-dredge survey); overflow from the hopper to ensure excessive sediment is not discharged; aerial photography during intensive plume monitoring surveys; and sensitive species health (eg mangroves).

adaptive management:

inspection and monitoring of dredging activities should be conducted to evaluate the effectiveness of

impact prevention strategies, and re-adjusted where necessary. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from indirect habitat loss and degradation in the study area is considered to be the following. 13.5.8.1 Coastal and Estuarine Habitat Pre-mitigation impacts related to indirect habitat loss and degradation were classified as moderate significance for coastal and estuarine habitats and, due to the lack of mitigation options available, residual impacts remain as moderate significance. 13.5.8.2 Intertidal Mudflats, Sandbanks and Sandy Beach Habitats Pre-mitigation impacts related to indirect habitat loss and degradation were classified as moderate significance for intertidal mudflats, sandbanks and sandy beach habitats and, due to the lack of mitigation options available, residual impacts remain as moderate significance. 13.5.8.3 Mangrove Habitats Pre-mitigation impacts related to indirect habitat loss and degradation were classified as moderate significance for mangrove habitats and, due to the lack of mitigation options available, residual impacts remain as moderate significance. 13.5.8.4 Marine Mammals Pre-mitigation impacts on the marine mammals through indirect habitat loss were classified as being of moderate significance for the West African manatee. Due to the lack of mitigation options available, residual impacts remain as moderate significance for the West African manatee. 13.5.8.5 Marine Birds Pre-mitigation impacts on the marine birds through indirect habitat loss were classified as being of minor significance for the Eurasian curlew. Due to the lack of mitigation options available, residual impacts remain as minor significance for the Eurasian curlew. 13.5.8.6 Marine Reptiles Pre-mitigation impacts on the marine reptiles through indirect habitat loss were classified as being of minor significance for the Olive Ridley sea turtle and moderate significance for Hawksbill, Leatherback, Loggerhead and Green turtles. Due to the lack of mitigation options available, residual impacts remain as minor significance for Olive Ridley sea turtles and moderate significance for Hawksbill, Leatherback, Loggerhead and Green turtles.


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13.5.8.7 Fish Pre-mitigation impacts on the fish through indirect habitat loss during were classified as being of minor significance for low value fish species, moderate significance for medium value species and major significance for high value fish species (eg elasmobranchs). Due to the lack of mitigation options available, residual impacts remain as minor significance for low vale fish species, moderate significance for medium value fish species and major significance for high value fish species (eg elasmobranchs). 13.5.9 Mitigation of Invasive Alien Species An Invasive Species Management Plan for the Project will be developed (taking into consideration the “IMO Guidelines for the Control and Management of Ships’ Ballast Water to Minimise the Transfer of Harmful Aquatic Organisms and Pathogens”) and the IMO International Convention on the Control of Anti-fouling systems on ships (AFS). This will set out the monitoring and management framework that will be implemented to minimise the risk of invasive species entering the marine and littoral environment. It will include measures for hull fouling control for vessels (including cleaning of equipment) and management of ballast water, including audits by the port authority. No ballast water discharges will be permitted in coastal waters for vessels coming from other bioregions. On-going maintenance and monitoring of the port and study area will include regular inspections for invasive alien species and measures will be implemented to remove unwanted species. Any methods used to control or prevent such species will not cause adverse impacts on the environment or communities. Operational monitoring of dredging activities will include checking for invasive species on dredging equipment. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from invasive alien species in the study area is considered to be the following. 13.5.9.1 Habitats and Species Pre-mitigation impacts on the habitats and species due to invasive alien species were classified as being of moderate significance for low value habitats / species, major significance for medium value habitats / species and critical significance for high value habitats / species. The mitigation measures associated with strict management of ballast water and cross border movement of equipment will lessen the risk of impact; therefore residual impacts reduce to minor significance for low value habitats / species, moderate significance for medium value habitats / species and major significance for high value habitats / species. 13.5.10 Mitigation of Induced Access An In-migration Management Plan sets out management and monitoring to minimise impacts from mass in-migration to the port area. The plan will include measures to protect biodiversity from the effects of in-migration and is described in more detail in Chapter 19: In-Migration. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from induced access in the study area is considered to be the following: 13.5.10.1 Mangrove Habitats Pre-mitigation impacts on the mangrove habitats through induced access were classified as being of major significance. The mitigation measures associated with an In-migration Management Plan will lessen the risk of impact; therefore residual impacts reduce to moderate significance for mangrove habitats. 13.5.10.2 Fauna Species


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Pre-mitigation impacts on the mangrove habitats through induced access were classified as being of major significance for high and medium value species (mainly benthic elasmobranchs and most turtle species) and moderate significance for species of low value. The mitigation measures associated with development and strict application of a comprehensive In-migration Management Plan will lessen the risk of impact; therefore residual impacts reduce to moderate significance for high and medium value species and minor significance for species of low value. 13.5.11 Mitigation of Waste and Marine Litter A Non-Mineral Waste Management Plan (NMWMP) will be developed and implemented, as discussed in Chapter 11: Resources and Non-Mineral Waste Management. This will include measures to minimise the risk of impacts from waste, including discharges, and will be established for the construction and operation of the port. The principal mitigation measures associated with discharges will be the application of relevant legislation regarding discharges, which will be highlighted in the NMWMP. The NMWMP will also include measures for: the collection and segregation of all waste types (non-hazardous and hazardous wastes); removal and disposal of waste, including litter; re-use or recycling of waste where possible (including donation to local communities); sending waste to landfill and landfill management; and maintaining records. All treatment plants and discharge points will be regularly inspected and maintained and monitoring of discharge quality will be undertaken to ensure correct operation. Sewage will treated in sewage treatment plants prior to discharge. Infrastructure shall be designed to prevent uncontrolled release of hazardous materials to the environment, or uncontrolled reactions (fire / explosion). Hazardous materials management will be supported by an appropriate design and risk assessment. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from waste in the study area is considered to be the following. 13.5.11.1 Habitats and Species Pre-mitigation impacts on the habitats and species through waste and marine litter were classified as being between minor significance for low value habitats / species to major significance for high value habitats / species. The mitigation measures associated with development and strict application of a comprehensive Non-Mineral Waste Management Plan will lessen the risk of impact; therefore residual impacts reduce to not significant for low value habitats / species through to moderate significance for high value habitats / species. 13.5.12 Mitigation of Non-Routine Events - Spills An Emergency Preparedness, Prevention and Response Plan will be developed for accidental spills and discharges. The Emergency Prevention, Preparedness and Response Plan will be implemented during each phase of activity. It will include:

emergency scenarios; provision and location of spill response and clean up equipment; spill containment and clean-up procedures; communication and notification protocol; training of staff; and testing and emergency drills.


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Use of marine pilots, navigational aids and controlled vessel movements (vessels will be held offshore for a berth to become available) will help to reduce the risk of collisions and spills. Application of these measures will reduce the likelihood of a spillage of any size and therefore reduce the magnitude of impact. Only those habitats and faunal groups that were assessed as being at risk of impacts of minor or greater significance are discussed below in terms of residual impacts following mitigation. Following the implementation of the mitigation measures listed above, the residual impacts from non-routine events (spills) in the study area is considered to be the following. 13.5.12.1 Habitats and Species Pre-mitigation impacts on the habitats and species through accidental spills were classified as being between minor significance for small spills and major significance for large spills. The mitigation measures associated with development and application of a comprehensive Emergency Preparedness, Prevention and Response Plan will lessen the risk of impact; therefore residual impacts reduce to not significant for small spills through to moderate significance for large spills. 13.5.13 Monitoring and Evaluation Monitoring and evaluation will be undertaken to determine whether mitigation measures are operating as intended, with the anticipated benefits to biodiversity. It will be designed in such a way that compliance with IFC Performance Standard 6 and Rio Tinto’s biodiversity strategy (including the Net Positive Impact goal) can be demonstrated. Two different types of monitoring will be implemented to track the Project’s biodiversity mitigation performance as follows. Monitoring of the implementation of actions listed in the SEMP and topic-specific Management Plans. In

other words, are mitigation actions being carried out in a timely and appropriate manner? Are Project staff complying with rules and procedures? Are budgets and staffing levels adequate? This kind of monitoring forms an integral part of each Management Plan. It is acknowledged that mitigation actions may evolve over time, based on feedback from adaptive management and evolving best practice; any changes to mitigation will be captured in the SEMP and relevant Management Plan.

Monitoring of the effectiveness of mitigation actions. In other words, are the actions producing the anticipated outcomes, for example maintaining good water quality, preventing declines in priority species and habitats, or preventing the establishment of new invasive species?

The second type of monitoring will include development of a Project-wide framework for monitoring and evaluation, with input from the Simandou Biodiversity Partners and appropriate experts. Monitoring will cover offset sites as well as impact sites, in order to track progress towards a Net Positive Impact at the regional level (this does not mean that exactly the same things will be monitored at impact and offset sites, but there will be appropriate congruence). Management Plans will include clear outcome-based objectives against which performance can be assessed. As well as monitoring the effectiveness of specific management interventions, more general monitoring will be carried out to track the status of biodiversity in the study area and at the selected offset sites. This will include the use of appropriate methods (including remote sensing and use of proxies / indicators where warranted) to track changes in the extent and quality of natural habitat (with a particular focus on high value habitats), and to track changes in population size, density and distribution of key species. The following list gives a few illustrative examples of the large number of monitoring activities that will be carried out: construction pile driving sound levels will be monitored to ensure the threshold for harm to marine

mammals and fish is not exceeded;


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all treatment plants and discharge points will be regularly inspected, maintained and monitored for discharge quality to ensure the standards of discharge are being met;

impacts to the coastline will be monitored by establishment of a monitoring programme, with coastal

management plan being developed if loss is attributed to the port; environmental impacts from dredging operation will be monitored through pre-dredge and operational

monitoring and surveys, with adaptive management implemented if required; presence and proliferation of invasive species will be monitored, with any occurrences of new species in

an area being reported immediately; and effectiveness of invasive and alien species control measures will be monitored. The results and any lessons learned will be used along with information from comparable projects elsewhere (especially other mining projects in tropical Africa) to feed into on-going adaptive management of the mitigation measures. 13.5.14 Offsets Strategy Biodiversity offsets involve conservation actions designed to compensate for the residual impacts of development projects to achieve a net gain in biodiversity over the long term. These conservation actions will apply to the Project as a whole and are described in more detail in Chapter 12: Terrestrial Biodiversity. 13.6 Summary of Findings Table 13.15 summarises the predicted impacts, mitigation measures and residual impacts reported in this chapter. Impacts are for both the construction and operation phases, unless otherwise stated.


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Table 13.15 Impact Summary Table

Description of Impact Evaluation Prior to Mitigation

Key Mitigation Residual Impact

Direct Habitat Loss

Offshore benthic habitats

Minor A dredge and spoil management plan (DSDMP) will be designed for the port and implemented throughout construction and operation. The purpose of the DSDMP is to set out the environmental mitigation and monitoring framework that will be implemented to ensure that any environmental impacts are minimised to as low as reasonably practicable. The DSDMP will identify and spatially define the different sensitive marine biodiversity attributes within the port study area and contain measures covering all aspects of the dredging operations. The DSDMP will include:

the dredging contractor will be required to provide modern fully equipped dredger(s) that meet the standards expected of best practice dredging, including installation of technology normally associated with modern dredgers, in line with Rio Tinto guidelines;

the type and size of dredger should also be selected based on the appropriate dredging method for the material being dredged and the characteristics of the dredging areas;

the dredgers will have monitoring and automation systems to improve dredging accuracy and efficiency; and

dredging and sediment disposal will only occur within the specified limits (both in area and depth) through the use of appropriate positioning technology.

Facilities in coastal areas will be located with sufficient setbacks to minimise impacts to littoral habitats, such as mangroves. In addition, a Project-specific Mangrove Management Plan (MMP) will be developed and implemented to reduce impacts to mangroves. The MMP will highlight the potential direct and indirect impacts that may occur to mangroves and give details of the mitigation, management and monitoring that will be implemented. Mitigation measures in the MMP will include:

mangrove shoreline and inland mangrove will be left intact if possible, without compromising navigational safety or construction access; and

measures will be implemented to ensure that cleared areas (or areas with other mangrove loss due to the port) are replanted with mangrove seedlings as soon as possible, if suitable for rehabilitation due to the new hydrodynamic regime and continued access requirements.

Minor

Coastal and estuarine habitats

Moderate Moderate


Minor Minor

Mangroves Moderate Minor


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Benthos Minor As for impacts from direct loss of habitats. Minor

Fish – high value Moderate Moderate

Fish – medium value Minor Minor

Fish – low value Not Significant Not Significant

West African manatee Moderate Minor

Eurasian curlew Minor Minor

Other marine birds Not Significant Not Significant

Direct Mortality

Fish – high value Moderate

Collisions and entrainment will be mitigated by:

inductions for all dredge vessel crew to cover awareness and procedures to be undertaken to minimise disturbance to marine fauna;

dredge suction pumps are not to be operated until within 0.5 m of the seabed, or as close as possible to the seabed to avoid fish entrainment;

dredge pumps will be turned off as soon as possible after the drag head clears the seabed;

turtle exclusion devices (tickler chains) will be fitted to dredgers to reduce the risk of entrainment of turtles (and benthic fish);

turtle exclusion devices (tickler chains) will be inspected regularly for damage to ensure effective use and if damage to the devices occurs frequently their use will be re-evaluated;

vessel operators and crews will maintain a vigilant watch for marine mammals and sea turtles and where feasible and safe to do so slow down or stop their vessel to avoid striking individuals;

all vessels will operate in line with pilotage speed restrictions, for example ‘no wake’ speeds while in the vicinity of manatee habitat and while in water depths where the draft of the vessel provides less than a 1.5 m clearance from the seabed / riverbed;

all personnel associated with the port will be instructed about the likely presence of manatees / turtles / cetaceans and the need to adhere to speed zones to avoid collisions with wildlife;

vessels within shipping channel and en route to and from dredge disposal sites will maintain speeds of less than 14 knots to reduce the likelihood of collisions with cetaceans;

when sea turtles and small cetaceans (eg dolphins) are sighted, vessels will maintain a distance of at least 50 m, whenever possible;

where feasible and safe to do so dredging operations will be shut down if a manatee / turtle / cetacean is

Minor

Fish – medium value Minor

Not Significant

Fish – low value Not Significant

Not Significant

Cetaceans – high value Moderate

Minor

Cetaceans – medium value (including the Atlantic humpback dolphin)

Minor Not Significant

Cetaceans – low value Not Significant

Not Significant

West African manatees Moderate

Minor

Olive Ridley sea turtle Minor Not Significant


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sighted within 50 m of the operation. Activities will not resume until the animal(s) has moved at least 50 m away from the operation or until an agreed time period has passed without sighting the animal within the 50 m safety zone. Animals must not be harassed or herded away;

all Project vessels will follow deep water routes wherever possible; and

vessel crews will report sightings of any injured or dead marine mammals, turtles or manatees immediately, regardless of whether the injury or death is caused by their vessel.

Other sea turtle species Moderate

Minor

Direct Noise

Cetaceans – high value Moderate Underwater noise will be mitigated through:

piling should preferably commence during daylight hours which allow a pre soft start observation period; the soft start period should commence only after a 30 minute pre-piling search of the observation zone of

500 m from the source;

soft start procedures of not less than 20 minutes will be used to slowly increase noise to enable marine mammals / reptiles / fish to move away from the noise source prior to commencement of full operational activities;

piling should not commence if marine mammals are detected in the mitigation zone or for 30 minutes after the last observation;

if marine mammals (including manatees) or turtles are observed in the vicinity of piling operations, the operations will be halted and will not resume until the animal(s) has moved at least 500 m away from the operation or until 30 minutes have passed without sighting of the animal within the 500 m safety zone;

animals must not be harassed or herded away;

if there is a break of greater than 10 minutes in piling activity then the soft start proceedures should be repteated;

all equipment and vessels will undergo regular maintenance to provide optimal performance; and

monitoring of Peak Sound Pressure Levels (SPL) during pile driving to ensure levels do not exceed the 180 dB re 1 μPa peak threshold for harm to marine mammals. If SPL exceed acceptable limits, further methods to reduce the sound pressure levels will be employed, such as use of a noise reduction device in the form of a shroud or physical screen around the anvil, pile sleeves and pile caps.

Minor

Cetaceans – medium value (including the Atlantic humpback dolphin)


Cetaceans – low value Not Significant Not Significant

West African manatees Moderate Minor

Eurasian curlew Minor Minor


Fish – high value Major – construction

Moderate – construction

Moderate – operation

Minor – operation

Fish – medium value Moderate – construction

Minor – construction

Minor – operation

Not Significant – operation

Fish – low value Minor – construction

Not Significant – construction




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Direct Altered Water quality

Cetaceans – all value species

Not Significant See direct loss of habitat for the dredge management plan and dredging contractor requirements. In addition the following mechanisms could be employed to reduce negative impacts to water quality:

drag heads will be designed to improve suction efficiency; and

ensuring equipment is properly calibrated

All treatment plants and discharge points will be regularly inspected, maintained and monitored for discharge quality to ensure the standards of discharge are being met. Contaminated runoff will be directed through sediment ponds to reduce the solids prior to discharge. Measures will be implemented to deal with acid sulphate soils in accordance with a Project-wide Acid Sulphate Soils Management Plan.

Not Significant

West African Manatee Not Significant

Not Significant

All marine bird species Not Significant

Not Significant

All sea turtle species Not Significant

Not Significant


Moderate


Minor


Minor

Minor – operation

Not Significant


Not Significant

Not Significant - operation

Not Significant


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Direct Altered Sediment Quality

Benthos Minor – construction

See altered water quality mitigation measures above. Minor


Not Significant


Moderate


Minor


Minor

Minor - operation

Not Significant


Not Significant


Not Significant

Direct Artificial Light

Eurasian curlew Minor Light disturbance will be mitigated during construction and operation through the use of low emission, directional lighting where possible. Where design of the infrastructure cannot prevent light spill from port facilities, screens will be established to prevent this impacting on beach areas.

Not Significant


Olive Ridley sea turtle Minor Not Significant

Other sea turtle species Moderate Minor

Indirect Habitat Loss and Habitat Degradation

Coastal and estuarine habitats

Moderate – construction

The Project will conduct monitoring to assess potential impacts to the coastline. Monitoring will include:

a monitoring programme will be designed based on modelling output and satellite imagery to assess natural change alongside Project induced change;

monitoring of the shape and alignment of the coastline using satellite imagery; and

comparison of the coastline for each monitoring event with previous monitoring results to assess coastline change.

Moderate - construction

Minor – operation

Minor – operation

Intertidal mudflats and sandbanks and sandy beaches

Moderate Moderate

Mangroves Moderate Moderate


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If coastal change attributed to the port development is observed during the monitoring studies, the Project will develop, regularly review and update a coastal management plan. In addition culverts will be used to maintain connectivity through waterways.

Monitoring and auditing of potential environmental impacts that may arise from the dredging operation will include pre and operational monitoring and surveys as well as adaptive management based on the results.

Measures will also be implemented to ensure that cleared areas (or areas with other mangrove loss due to the port) are replanted with mangrove seedlings, if suitable for rehabilitation due to the new hydrodynamic regime. These measures will be implemented through the development of a Project-specific Mangrove Management Plan (MMP).

West African manatees

Moderate Minor

Eurasian curlew



Olive Ridley sea turtle Minor Minor

Other sea turtle species Moderate Moderate

Fish – high value Major - construction

Major


Moderate

Fish – low value Minor - construction

Minor

Invasive Alien Species

High value species Critical

An Invasive Species Management Plan for the Project will be developed (taking into consideration the “IMO Guidelines for the Control and Management of Ships’ Ballast Water to Minimise the Transfer of Harmful Aquatic Organisms and Pathogens”) and the IMO International Convention on the Control of Anti-fouling systems on ships (AFS). This will set out the monitoring and management framework that will be implemented to minimise the risk of invasive species entering the marine and littoral environment. It will include measures for hull fouling control for vessels (including cleaning of equipment) and management of ballast water, including audits by the port authority. No ballast water discharges will be permitted in coastal waters for vessels coming from other bioregions. Appropriate reception and treatment facilities will be provided.

On-going maintenance and monitoring of the port and study area will include regular inspections for invasive alien species and measures will be implemented to remove unwanted species. Any methods used to control or prevent such species will not cause adverse impacts on the environment or communities. Operational monitoring of dredging activities will include checking for invasive species on dredging equipment.

Major

Medium value species and habitats

Major

Moderate

Low value species and habitat

Moderate

Minor


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Induced Access

Mangrove habitats Major

An In-migration Management Plan sets out management and monitoring to minimise impacts from mass in-migration to the port area. The plan will include measures to protect biodiversity from the effects of in-migration and is described in more detail in Chapter 19: In-Migration.

Moderate

High value species Major Moderate

Medium value species Major Moderate

Low value species Moderate Minor

Waste and Marine Litter

High value species Major

A Non-Mineral Waste Management Plan (NMWMP) will be developed and implemented, as discussed in Chapter 11: Resources and Non-Mineral Waste Management. This will include measures to minimise the risk of impacts from waste, including discharges, and will be established for the construction and operation of the port. The NMWMP will include measures for:

the collection and segregation of all waste types (non-hazardous and hazardous wastes);

removal and disposal of waste, including litter;

re-use or recycling of waste where possible (including donation to local communities);

sending waste to landfill and landfill management; and

maintaining records.

All treatment plants and discharge points will be regularly inspected and maintained and monitoring of discharge quality will be undertaken to ensure correct operation. Sewage will treated in sewage treatment plants prior to discharge.

Infrastructure shall be designed to prevent uncontrolled release of hazardous materials to the environment, or uncontrolled reactions (fire / explosion). Hazardous materials management will be supported by an appropriate design and risk assessment.

Moderate

Medium value habitats and species

Moderate

Minor

Low value habitats and species

Minor

Not Significant

Non-routine events – spills

Non-routine spills have been assessed using a risk based approach. Impact significance varies based on receptor value and magnitude. Magnitude includes risk, which is a function of the likelihood of occurrence and potential consequences. Due to this approach there are too many variables to present below. Impacts prior to mitigation range from critical to not significant. After mitigation likelihood is reduced and impacts range from moderate to not significant. The table below does not attempt to show all potential outcomes from the assessment but highlights the worst case only. See assessment above for further detail.


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Large magnitude impacts on high value receptors

Critical An Emergency Preparedness, Prevention and Response Plan will be developed for accidental spills and discharges. The Emergency Prevention, Preparedness and Response Plan will be implemented during each phase of activity. It will include:

emergency scenarios;

provision and location of spill response and clean up equipment;

spill containment and clean-up procedures;

communication and notification protocol;

training of staff; and

testing and emergency drills.

Use of marine pilots, navigational aids and controlled vessel movements (vessels will be held offshore for a berth to become available) will help to reduce the risk of collisions and spills. Application of these measures will reduce the likelihood of a spillage of any size and therefore reduce the magnitude of impact.

Moderate

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