CHAPTER FOUR THE QUALITY OF ESTUARINE AND COASTAL … 4... · Galway city (Inner Galway Bay). The...

Water Quality in Ireland 2004-2006 Chapter Four

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CHAPTER FOUR

THE QUALITY OF ESTUARINE AND COASTAL

WATERS

INTRODUCTION

Estuaries and their adjoining coastal waters are often categorised as ‘receiving waters’

due to the fact that these waters receive inputs of various substances from a wide range

of human activities. The rivers that flow into estuaries can carry substantial loads of

nutrients, organic matter and other materials that originate from upstream sources. In

many cases large urban populations are located close to estuaries with the result that

substances arising from municipal and industrial sources are often discharged directly to

these tidal waters.

Given their downstream location and proximity to large urban centres the water quality

status of these receiving waters provides a valuable indicator of the general quality

conditions of surface and ground waters in the surrounding catchments. Furthermore,

information on changes in the environmental status of these waters provides an insight

into the effectiveness of pollution control measures that have been put in place to reduce

and control the impacts that may arise from certain polluting activities.

In recent years, greater urbanisation, industrialisation and the intensification of

agricultural practices has increased the range of pressures that have the potential to

impact negatively on the quality of these waters. In addition to these internal pressures,

further stresses from external sources, such as transboundary pollution (e.g.,

radioactivity) and accidental or in some cases intentional oil spills from marine vessels,

also have the potential to adversely affect their status.

This chapter presents an assessment of these different pressures and their associated

impacts and therefore provides an overview of the water quality status of estuarine and

coastal waters around Ireland. The information was collected by a number of

monitoring agencies, including the Environmental Protection Agency, the Marine

Institute, the Irish Coast Guard and the Radiological Protection Institute of Ireland.


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EUTROPHICATION TENDENCY AND GENERAL QUALITY CONDITIONS

IN ESTUARINE AND COASTAL WATERS

The impact of nutrient enrichment and the process of eutrophication is a major concern

in the marine environment. Globally, there is widespread evidence that inputs of

nutrients to estuarine and coastal waters are causing significant changes to plant and

animal communities. The deleterious effects of excessive nutrient enrichment include

increases in the frequency and duration of phytoplankton blooms (in some cases of

nuisance and toxin emitting species), depletion of dissolved oxygen resulting in the

mortality of marine organisms, and changes to the structure and functioning of marine

food webs. In addition, nutrient enriched waters may experience excessive growth and

strandings of macroalgae that typically produce very strong odours and visual impact as

they degrade on beaches and shorelines.

The EU directives on urban waste water treatment (CEC, 1991a) and nitrates from

agricultural sources (CEC, 1991b) are among the most important measures in place to

combat eutrophication of surface waters. The tidal water bodies that have been

designated as sensitive areas, under national regulations (S.I. 254 of 2001 and S.I. 440

of 2004) implementing the urban waste water treatment directive, are shown in Table 1.

If deemed necessary these designated waters may require even more stringent treatment

of discharges.

Table 1

Designated sensitive areas in tidal waters under national regulations (S.I. 254 of

2001 and S.I. 440 of 2004).

Water body

Water body Upper Lee estuary (Tralee) Owenacurra estuary/North Channel

Inner Broadmeadow estuary Upper Feale estuary

Liffey estuary Cashen Feale estuary

Upper and Lower Slaney estuary Killybegs Harbour

Barrow estuary Castletown estuary (Dundalk)

Upper Suir estuary Upper and Lower Blackwater estuary

Upper and Lower Bandon estuary Lee estuary/Lough Mahon

Ireland has seen significant infrastructural investment in waste water treatment facilities

in recent years with 82 per cent of waste water arising in 2004-2005 receiving at least


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secondary treatment (EPA, 2007a). This represents a significant improvement from the

period 2000-2001, when only 21 per cent of discharges received secondary treatment,

and 41 per cent of discharges received only primary treatment. A number of major

plants, that discharge to estuarine waters, were commissioned during the period 2004-

2005, including, Cork city (Lough Mahon), Limerick city (Upper Shannon estuary) and

Galway city (Inner Galway Bay). The level of treatment of discharges is expected to

increase further as additional treatment plants come into operation in the coming years.

Plans for the provision of new plants and upgrades to existing plants form part of

Ireland’s National Water Services Investment programme 2005-2007.

Similarly, the risk of nutrient loss associated with agricultural activities is receiving

considerable attention at present. Ireland’s national Nitrates Action Programme (NAP)

was given statutory effect by the European Communities (Good Agricultural Practice

for Protection of Waters) Regulations S.I. 378 of 2006. The overall objective of the

programme is to reduce the loss of both nitrogen and phosphorus from agricultural

lands to surface waters. Since these waters ultimately drain to the sea, carrying the

accumulating nutrient burdens that they pick up along the way, estuaries and coastal

waters are vulnerable to nutrient related ecological disturbance, and are likely therefore

to show both the adverse consequences of excessive enrichment and the benefits of

measures taken to combat these problems.

Under the structures established by the Water Framework Directive (WFD)

(2000/60/EC) the measures outlined above to address both point and diffuse pollution

sources will be consolidated with other measures to ensure that the environmental

objectives set out in the directive are achieved. The detail of how individual measures

will come together to address a range of issues will be set out in River Basin

Management Plans (RBMPs). Many of the measures referred to above in relation to

waste water treatment and reducing and controlling pollution from agricultural sources,

are likely to form an important part of individual RBMPs. These measures will support

the basic measures of the WFD and the requirements of the other 11 directives

specifically referred to in the directive.


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Trophic Status of Irish Estuarine and Coastal Waters

The assessment of the trophic status of estuarine and coastal waters around Ireland is

mainly based on the analysis of data collected by the EPA between 2002-2006 (Figure

1). Additional data from the Marine Institute’s annual winter nutrient monitoring in the

western Irish Sea and eastern Celtic Sea are also included.

A Trophic Status Assessment Scheme (TSAS) for the classification of these waters has

been developed and is reported in detail in Toner et al., (2005). The scheme, which was

designed to capture the cause-effect relationship of the eutrophication process is

summarised in Table 2. The scheme works by assessing the level of compliance of a

range of parameters and their associated assessment levels that are considered to be

indicative of good environmental quality. To summarise, both dissolved inorganic

nitrogen (DIN) and ortho-phosphate (MRP) levels are assessed in summer and winter,

chlorophyll data are assessed using a median and 90 percentile approach and oxygen

conditions are assessed both in respect of deoxygenation and supersaturation.

The nutrient values applied in TSAS were developed specifically for estuarine and

nearshore coastal waters. Additional values for application in coastal and offshore

waters have also been developed based on data collected from the western Irish Sea

between 1990 and 2000 and more recently from the eastern Celtic Sea (McGovern et

al., 2002). These values were recently used to assess the trophic status of a number of

coastal and offshore areas of the western Irish Sea and eastern Celtic Sea (see below) as

part of the OSPAR1 Common Procedure.

A further element of the TSAS system includes a qualitative approach to observing the

distribution of opportunistic macroalgae such as Enteromorpha (Thongweed) and Ulva

(Sea Lettuce). This approach has been further developed and will be used formally to

assess one of the biological elements as required by the Water Framework Directive

(Box 1).

1 The Convention for the Protection of the Marine Environment of the North-East Atlantic (the “OSPAR Convention”), of which Ireland is a signatory, was opened for signature at the Ministerial Meeting of the Oslo and Paris Commissions in Paris on 22 September 1992.


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Figure 1. Location of estuarine and coastal areas sampled in the period 2002-2006.

Slaney Estuary and Wexford Harbour

Avoca Estuary

Liffey Estuaryand Dublin Bay

Rogerstown and Broadmeadow Estuaries

Castletown Estuaryand Dundalk Bay

Blackwater Estuaryand Youghal Harbour

Colligan Estuaryand Dungarvan Harbour

Barrow/Nore/Suir Estuariesand Waterford Harbour

Bandon Estuaryand Kinsale Harbour

Lee Estuary, Lough Mahon, Owenacurra EstuaryNorth Channel and Cork Harbour

Shannon Maigue Deeland Fergus Estuaries

Cashen-Feale Estuary

Lee Estuaryand Tralee Bay

Corrib Estuary and Galway Bay

Garavogue Estuary and Sligo Bay[incl. Ballysadare/Drumcliffe Bay]

Moy Estuaryand Killala Bay

Killybegs Harbour

Swilly Estuaryand Lough Swilly

Boyne Estuaryand Plume Zone

Argideen Estuary

Erne Estuary


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Table 2

Parameters and criteria used in the Trophic Status Assessment Scheme (TSAS) scheme

for Irish estuaries, bays and nearshore coastal waters.

Eutrophic water bodies are those in which each of the criteria are breached, i.e. where elevated

nutrient concentrations, accelerated growth of plants and undesirable water quality disturbance

occur simultaneously; Potentially Eutrophic water bodies are those in which two of the criteria

are breached and the third falls within 15 per cent of the relevant threshold value; Intermediate

Status water bodies are those which do not fall into the Eutrophic or Potentially Eutrophic

classes but in which breaches one or two of the criteria occur; Unpolluted waterbodies are

those which do not breach any of the criteria.

Parameter Numeric Criterion

Statistic Period to which Criterion Applies

Category A (Nutrient Enrichment) Dissolved Inorganic Nitrogen mg/l Tidal Fresh Waters >2.6 Median Winter or Summer

Intermediate Waters1 >1.4 Median Winter or Summer

Full salinity Water2 >0.25 Median Winter or Summer

Ortho-phosphate (MRP) µg/l Tidal Fresh Waters >60 Median Winter or Summer Intermediate Waters1 >60 Median Winter or Summer Full salinity Water2 >40 Median Winter or Summer

Category B (Accelerated growth)

Chlorophyll (µg/l)

Tidal Fresh Waters >15 or >30 Median and 90%ile Summer Intermediate Waters1 >15 or >30 Median and 90%ile Summer Full salinity Water2 >10 or >20 Median and 90%ile Summer

Category C (Undesirable disturbance)

Dissolved Oxygen (per cent Sat) Tidal Fresh Waters <70 or >130 5%ile and 95%ile Summer Intermediate Waters1 <70 or >130 5%ile and 95%ile Summer Full salinity Water2 <80 or >120 5%ile and 95%ile Summer

1 17 psu 2 35 psu


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Results for the 2002-2006 Trophic Status Assessment

The outcome of the most recent trophic status assessment of estuarine and coastal

waters for the period 2002-2006 is shown in Figure 2. Of the 69 water bodies included

in the assessment, 13 (18.9%) were classed as eutrophic, 2 (2.9%) as potentially

eutrophic, 27 (39.1%) as intermediate and 27 (39.1%) were unpolluted.

The status of tidal waters has changed little since the previous assessment that covered

the period 1999-2003. The condition of just over 85 per cent, or 60 of the 69 water

bodies assessed, has remained unchanged and as a result the proportion of water bodies

in each status category is similar to the last assessment (Table 3). Of the 9 water bodies

that have changed in status 6 have shown a decline in status while 3 have shown an

improvement. The Upper Blackwater estuary and Wexford Harbour are now classified

as eutrophic having previously being classified as potentially eutrophic and

intermediate, while Dungarvan Harbour, the Lower Lee (Tralee) estuary, and Sligo

Harbour have all moved from the unpolluted category to intermediate. Of the 12 water

bodies classed as eutrophic in the 1999-2003 assessment, 11 remain so, with only

Lough Mahon, which is now classified as intermediate, having improved in status.

Improvements were also observed in the Boyne estuary, which has moved from being

potentially eutrophic in the previous assessment to intermediate in the current period,

and in the Upper Feale estuary, which is now considered to be unpolluted. A

comparison of the status of each water body in the periods 2002-2006 and 1999-2003 is

shown in Appendix IV.1.

Table 3

Summary of the outcome of the TSAS analysis for the period 2002-2006, with

comparative figures for the 1999 – 2003 and 1995-1999 periods. Water Bodies Trophic Class 2002-2006 1999-2003 1995-1999 Numbers Eutrophic 13 12 15 Potentially Eutrophic 2 3 3 Intermediate 27 28 18 Unpolluted 27 26 24 Total 69 69 60

Percentage

Eutrophic 18.9 17.4 25.0

Potentially Eutrophic 2.9 4.3 5.0 Intermediate 39.1 40.6 30.0 Unpolluted 39.1 37.7 40.0 Total 100 100 100


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Figure 2. Estuarine and coastal water quality 2002-2006.

3

5

8

11

1314

16

21

2728

29

46

53

54

5556

57

58

63

61

62

68

69

52

50

47

34

23

25

2

4

7

10

12

17

64

22

24

26

30

35 3839

48

49 51

59

6566

67

15

31

36

45

60

42

1

69

19

33

37

40

4143

44

2018

32

Eutrophic 18.9%

Potentially Eutrophic 2.9%

Intermediate 39.1%

Unpolluted 39.1%

No. Location No. Location No. Location

1 Castletown Estuary 24 Barrow Nore Estuary 47 Upper Feale Estuary

2 Inner Dundalk Bay 25 Upper Suir Estuary 48 Cashen Feale Estuary

3 Outer Dundalk Bay 26 Lower Suir Estuary 49 Deel Estuary

4 Boyne Estuary 27 Barrow Nore Suir Estuary (Outer) 50 Fergus Estuary

5 Boyne Estuary Plume Zone 28 Outer Waterford Harbour 51 Maigue Estuary

6 Rogerstown Estuary (Inner) 29 Waterford Harbour Adjacent Coastal 52 Tidal Shannon River

7 Rogerstown Estuary (Outer) 30 Colligan Estuary 53 Upper Shannon Estuary

8 Rogerstown Estuary Adjacent Coastal 31 Dungarvan Harbour 54 Lower Shannon Estuary

9 Broadmeadow Estuary (Inner) 32 Upper Blackwater Estuary 55 Corrib Estuary

10 Broadmeadow Estuary (Outer) 33 Lower Blackwater Estuary 56 Inner Galway Bay North

11 Broadmeadow Estuary Adjacent Coastal 34 Youghal Harbour 57 Moy Estuary

12 Liffey Estuary 35 Lee Estuary 58 Killala Bay

13 Dublin Bay 36 Lough Mahon 59 Garavoge Estuary

14 Dublin Bay Adjacent Coastal 37 Owenacurra Estuary 60 Sligo Harbour

15 Avoca Estuary 38 North Channel Great Island 61 Sligo Bay

16 Avoca Estuary Adjacent Coastal 39 Cork Harbour 62 Ballysadare Bay

17 Upper Slaney Estuary 40 Upper Bandon Estuary 63 Erne Estuary

18 Lower Slaney Estuary 41 Lower Bandon Estuary 64 Erne Estuary Adjacent Coastal

19 South Wexford Harbour 42 Kinsale Harbour 65 Killybegs Harbour

20 Wexford Harbour 43 Argideen Estuary 66 McSwyne's Bay

21 Wexford Harbour Adjacent Coastal 44 Upper Lee (Tralee) Estuary 67 Upper Swilly Estuary

22 Nore Estuary 45 Lower Lee (Tralee) Estuary 68 Lower Swilly Estuary

23 Barrow Estuary 46 Tralee Bay 69 Lower Lough Swilly


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Box 1. The assessment of macroalgal blooms in transitional waters - a case study in the Argideen estuary,

west Cork.

The assessment tool that has been developed for the Water Framework Directive (WFD) is based on

measuring the spatial coverage of seaweed blooms in a water body and the amount of seaweed present in

these accumulations.

The Argideen estuary is located in west Cork and extends from the village of Timoleague to

Courtmacsherry harbour. This area has been experiencing increased levels of macroalgal accumulations

in recent years and these events have become an annual occurrence. This area was classified as eutrophic

in the previous assessment based on general qualitative observations of the algae cover and the water

body has now been assessed using the formal WFD monitoring protocol. Data gathered during a recent

research project (Wilkes 2004) has also been used to help develop and refine the tool.

Results from both 2004 and 2006 (below) show that the scale of macroalgal growth is elevated in terms of

spatial extent and biomass. Over 30 per cent of the suitable substrate was covered in algal mats and in

some areas the biomass of seaweed exceeded 4000 gm-2. Data from other areas suggest that background

levels of green algal abundance is generally less than 100 gm-2. The classification tool assessed the water

body as being in poor ecological status in both 2004 and 2006.

A summary of the data used in the above assessment is shown below (Figures 3-5) and

individual summary statistics for each area are given in Appendix IV.2. The level of


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exceedance for an assessment parameter is presented as a percentage deviation from the

respective assessment level. The use of percentages normalises for the effects of

salinity, allowing a much clearer presentation of the environmental conditions existing

in each of the water bodies assessed. The percentage exceedance for a range of

parameters including summer and winter dissolved inorganic nitrogen (DIN),

molybdate reactive phosphorus (MRP), summer chlorophyll and summer oxygenation

conditions for each of the 69 water bodies assessed over the period 2002-2006 is shown

in Figures 3 and 4. In addition, the level of biochemical oxygen demand (BOD), which

measures bacterial oxidation of organic matter, is shown in Figure 5.

A number of estuaries, mainly located along the eastern, southeastern and southern

coasts breached the winter dissolved inorganic nitrogen criterion with the highest

percentage deviations (greater than 50 per cent) being observed in the Castletown,

Rogerstown (Inner), Broadmeadow (Inner & Outer), Upper Slaney, Lower Slaney,

South Wexford Harbour, Lower Suir, Lough Mahon, Owenacurra, Cork Harbour and

the Upper Bandon estuary. The highest median DIN concentrations ranging between

4.0– 6.5 mg/l (285 – 464 µM) were found in the Castletown, Rogerstown, Upper Slaney

and Upper Bandon estuaries. In contrast, with the exception of the Liffey and Deel

estuaries, very few areas exceeded the winter MRP criterion. In summer, a noticeable

reduction in the magnitude and number of areas exceeding the DIN criterion was clearly

evident, nevertheless the Upper Slaney, Barrow, Nore, Barrow Nore and Lower Suir,

Upper Blackwater and Owenacurra estuaries still breached the prescribed level for this

parameter. For MRP the situation in summer was similar to that in winter, although

during the summer period, elevated levels of this nutrient were also observed in the

Maigue, Upper Lee (Tralee), Rogerstown (Inner) and Castletown estuaries.

Elevated chlorophyll levels, Figure 4, were most frequently observed in the estuaries

along the southern and south-eastern coasts with the highest chlorophyll concentrations

of between 18.9 – 43.1 µg/l (median) and 33.3 – 81.9 µg/l (90 percentile) being found in

the Castletown, Lower Slaney, South Wexford Harbour, Upper Blackwater, Upper and

Lower Bandon, Cashen Feale and Upper Swilly estuaries as well as the coastal waters

adjacent to the Erne estuary. The high chlorophyll values found in waters adjacent to

the Erne are likely to be associated with the fallout from a large phytoplankton bloom

which occurred all along the western seaboard during the summer of 2005 (Box 2).


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Deoxygenation was observed in 12 of the 69 water bodies assessed, but in the majority

of these values were greater than 60 per cent saturation (or approx. 5.5 mg/l O2) a value

considered adequate to support aquatic life. Lower saturation values ranging between

40-60 per cent saturation, indicating significant levels of oxygen depletion, were

observed in the Avoca, Upper Lee (Tralee), Cashen Feale, Lee and Upper Swilly

estuaries and the coastal waters of McSwyne’s Bay. The lowest oxygen value recorded

during the 2002-2006 period were from the upper part of the Avoca estuary where

levels were as low as 13 per cent saturation or approximately 1.0 mg/l O2 during the

summer of 2006. These levels represent low oxygen or hypoxic conditions that are

likely to cause adverse effects in most aquatic organisms. With the exception of these

four water bodies no anoxic or hypoxic conditions (i.e., oxygen levels < 2.0 mg/l O2)

were observed in any of the other water bodies surveyed.

The levels of oxygen supersaturation, an indicator of excessive phytoplankton activity is

shown in Figure 4. While excessive phytoplankton photosynthesis during daytime can

lead to oxygen supersaturation, the drawdown of oxygen at night due to nocturnal

respiration, in the absence of photosynthesis, can result in oxygen deficiency. Oxygen

supersaturation appears more prevalent than oxygen depletion occurring in 20 of the 69

waters surveyed, but in the majority of these the respective criterion level is only

marginally breached. The highest supersaturation values between 140-160 per cent

were observed in the Rogerstown (Inner), Lower Slaney, Colligan, Upper Blackwater,

Upper and Lower Bandon estuaries and in Dungarvan Harbour.

The effect of organic enrichment on oxygenation conditions, as indicated by the

biochemical oxygen demand (BOD) concentration is shown in Figure 5. Over two-

thirds or 47 of the 69 water bodies assessed are considered to have an acceptable level

of BOD (i.e., 95 percentile less than 4 mg/l O2) indicating the absence of any significant

organic loading. However, in 22 water bodies the level of oxygen demand observed

indicated the presence of substantial organic enrichment, with seven of these areas, the

Upper Swilly estuary, the Liffey estuary, South Wexford Harbour, Youghal Harbour,

Upper Bandon estuary, Cashen Feale estuary and Erne estuaries having BOD values

ranging from 6.0-10.0 mg/l O2.


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Figure 3. Percentage below (grey circles) and above (coloured circles) the

assessment levels (AL) for winter and summer dissolved inorganic nitrogen (DIN)

and dissolved inorganic molybdate reactive phosphorus (MRP) in each of the

water bodies assessed between 2002-2006.

Winter DIN Winter MRP

Per cent deviationfrom

assessment level

-100 to -50

-50 to 0

0 to 50

50 to 100

100 to 150

150 to 200

Summer DIN Summer MRP


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Per cent deviation from

assessment level

-100 to -50

-50 to 0

0 to 50

50 to 100

100 to 150

150 to 200

Summer median chlorophyll

Summer 90 percentile chlorophyll

Dissolved oxygenundersaturation

Dissolved oxygensupersaturation

Per cent deviation from

assessment level

-100 to -50

-50 to 0

0 to 25

25 to 50

50 to 75

Figure 4. Percentage below (grey circles) and above (coloured circles) the

assessment levels (AL) for summer chlorophyll and summer dissolved oxygen

undersaturation and supersaturation in each of the water bodies assessed between

2002-2006.


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Figure 5. BOD concentrations (95 percentile) in each of the water bodies surveyed

between 2002-2006.

BOD mg/l

0 to 2

2 to 4

4 to 6

6 to 8

8 to 10

Biochemical Oxygen Demand


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Specific Observations in Relation to Water Management

A number of measures have been put in place to reduce and control the environmental

impacts of certain human activities that affect the quality of tidal waters. These

measures include the provision of upgraded or new waste water treatment facilities,

licensing of industrial and waste activities and the adoption and implementation of the

Nitrates Action Programme. In this section observations made during this current

assessment together with those made in previous assessments are summarised in an

attempt to evaluate the effectiveness of existing and planned measures. This section

deals specifically with those areas where measures have been applied and can be

assessed. It also identifies those areas where improved or indeed new measures are

required to deal with existing water quality issues.

Castletown Estuary and Inner Dundalk Bay Since 2000 the waste water treatment

plant at Soldier’s Point, Dundalk, has been discharging biologically treated effluent to

Inner Dundalk Bay. The improvements in nutrient conditions, observed in the previous

assessment (1999-2003) have been maintained although elevated chlorophyll levels

were still present during the current assessment. While levels of nitrogen and

phosphorus in the Castletown estuary continue to breach their respective criteria there

appears to have been a marked improvement in oxygenation conditions with the level of

oxygen saturation having increased from between 33–38 per cent in the last two

assessments, to 70 per cent saturation in the current assessment. The improvement in

oxygen levels is also reflected in Inner Dundalk Bay, which is now in compliance with

both oxygen criteria having previously been in breach of the oxygen undersaturation

criterion.

While oxygen conditions within the estuary have improved since the last assessment,

BOD levels are still unacceptably high and above the recommended level of 4 mg/l O2

(95 percentile). Although waste water and other discharges into this reach were

probably the main cause of elevated BOD levels, it is also likely that Port activity

involving the offloading of biodegradable matter in the form of bulk grains may be

increasing the level of organic loading to the estuary.

The median concentration of dissolved inorganic nitrogen (DIN) in the Castletown

estuary in winter has increased substantially from a value of 2.6 mg/l in the period


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1999-2003 to 4.6 mg/l in the current assessment. This observation would appear to add

further evidence to the suggestion made in the previous report that the upgraded waste

water treatment plant is discharging more biologically available inorganic nitrogen than

it did prior to upgrading. Since both the Castletown estuary and Inner Dundalk Bay are

designated as sensitive areas, the case for installing nitrogen removal should be

investigated. However, any such investigation, should first attempt to quantify the

magnitude of upstream nitrogen loading from both the Castletown and Flurry rivers.

Liffey Estuary and Dublin Bay The present assessment of the Liffey estuary would

appear to confirm that water quality in the estuary continues to improve with only

phosphorus levels in winter marginally exceeding the set criterion. Since the 1995-1999

period the trophic status of the estuary has improved from eutrophic to intermediate in

1999-2003 and in the current assessment period. As in the previous assessment summer

chlorophyll levels in the estuary remained low with values of 3.2 (median) and 5.6 (90

percentile) µg/l respectively. Dissolved oxygen levels showed little evidence of

disturbance ranging between 80 and 119 per cent saturation.

The observed improvement in water quality in the Liffey estuary is clearly a result of

the installation of significantly upgraded treatment facilities at the Ringsend WWTP,

though further investigation is still required to track the change in nutrient levels as the

full effect of the plant is realised. In the previous period 1999-2003, there was some

evidence to suggest that while total and ammoniacal nitrogen concentrations had fallen

as a consequence of nitrification, oxidised nitrogen levels had increased. It had been

suggested that this situation should be kept under review in case it might lead to the re-

occurrence of excessive nitrogen availability in the estuary. It would appear though

from examination of data collected during the current assessment period that levels of

total oxidised nitrogen in the estuary have changed little in the intervening period.

BOD concentrations were generally low, as indicated by the median value of 2.0 mg/l

O2 in both the estuary and Dublin Bay. Given that this value is also the limit of

detection for the method used, at least half of the reported measurements were less than

2.0 mg/l O2. In Dublin Bay, 80 per cent of BOD values were reported at the limit of

detection indicating that the ‘true’ median value for the Bay is much lower than the


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limit of detection. However, as can be seen from Figure 5, the Liffey estuary and

Dublin Bay were both in breach of the recommended 95 percentile BOD value of 4 mg/l

O2. In the estuary the exceedance was the result of a small number of high BOD values

in the range 12 – 27 mg/l O2 collected adjacent to the Ringsend effluent cascade. These

high BOD values were mostly restricted to 2002 and data collected since then indicate a

decline in BOD values both within the lower estuary and particularly in the vicinity of

the Ringsend discharge – again indicating an improvement in the quality of the

discharge at this point. The reduction in organic loading from Ringsend, as indicated by

declining BOD values, is also reflected in the considerable improvement in the

bacteriological quality of the Liffey estuary and bathing areas within the Dublin Bay

area.

One potentially negative aspect of water quality trends in the Liffey estuary and Dublin

Bay has been the reoccurrence of opportunistic macroalgae in the Tolka estuary and

along the south Dublin seashore. The occurrence of green opportunistic algal mats

(mostly Enteromorpha spp.) in the intertidal area of the Tolka estuary, mainly behind

the southern promontory of Bull Island, is of concern. The presence of these mats,

which can have an adverse impact on marine benthic fauna, in terms of smothering the

underlying sediment, is likely to result in the Tolka estuary being classified as less than

good ecological status under the WFD. Furthermore, the reoccurrence of substantial

strands of brown macroalgae (Ectocarpus siliculosis) along the south Dublin seashore

during the autumn months is also of concern. The abundance and distribution of

opportunistic algal species within the Dublin Bay area will be assessed as part of the

national WFD monitoring programme. If the accumulation of these macroalgal blooms

result in a water body failing to meet its environmental objective under the Directive,

then investigative monitoring will be required to determine their cause.

Avoca Estuary and Arklow Harbour As indicated above the lowest dissolved oxygen

concentrations observed during the current assessment period were recorded in the

upper reach of the Avoca estuary in the vicinity of Arklow Bridge. This is an

unsatisfactory situation that should be addressed as a matter of urgency. The

construction of the planned Arklow waste water treatment plant, which would improve

existing conditions within the estuary, has been delayed.


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Estuaries of the south and southeast Nearly all the rivers that flow into the assessed

estuaries along the south and southeast coasts of Ireland exhibit elevated nitrogen

concentrations. The upper tidal reaches of the Slaney, Barrow, Nore, Blackwater, and

Bandon estuaries, all breached the dissolved inorganic nitrogen criterion. It is also

likely, given the elevated levels observed in the lower estuary, that the Upper Suir

estuary would also have breached the winter DIN assessment level if data had been

available from the winter period. The highest nitrogen concentrations were observed in

the upper Slaney and upper Bandon estuaries, with median DIN concentrations ranging

between 5.2 and 5.7 mg/l.

In addition to breaching the nitrogen criterion, two of these estuaries, the Barrow and

Upper Nore failed the oxygen criteria and came close to breaching the chlorophyll

criteria and as such were designated as potentially eutrophic. Two of the estuaries, the

Upper Blackwater and Upper Bandon estuaries failed all three criteria and were

therefore categorised as eutrophic. In the previous assessment, to 2003, the upper reach

of the Blackwater had been classed as potentially eutrophic rather than eutrophic but

this would now appear only to have been a temporary improvement. The Lower Slaney

estuary, the Lower Blackwater estuary and the Lower Bandon estuary were again

classed as eutrophic in the current period – a designation that has not changed over the

last three assessment periods. It would appear that the tendency towards eutrophication

in these reaches is primarily being caused by the high nitrogen concentrations in the

riverine inflows.

As in the last assessment the southern portion of Wexford Harbour, south of the

southern training walls, is classed as eutrophic. Since it is very shallow and relatively

sheltered, with flushing rates probably much lower than those in the main body of

Wexford Harbour, the South Harbour may be naturally predisposed to high algal

productivity. There appears to have been a decline in the water quality status of the

main harbour area that had previously been classified as intermediate (based on elevated

nitrogen levels) in 1995-1999 and again in 1999-2003. While phosphorus

concentrations in winter and summer remain low (the harbour was in breach of this

criterion in 1995-1999) elevated levels of nitrogen, most likely from the Slaney estuary,

and excessive phytoplankton activity and oxygen supersaturation means that Wexford

Harbour is now classed as a eutrophic water body.


4-19

While the trophic status of Youghal Harbour, which was categorised as unpolluted in

the current assessment, has remained unchanged, there are concerns that the discharge

of untreated sewage is impacting negatively on the quality of this receiving water. As

indicated by Figure 5, BOD concentrations recorded in this water body are unacceptably

high with a 95 percentile BOD value of 7.9 mg/l O2, well above the recommended value

of 4 mg/l O2. Nevertheless, these elevated BOD values are likely to be addressed by the

provision of a new waste water treatment plant in Youghal, which is due to commence

construction in late 2009/early 2010.

Cork Harbour and the Lee and Owenacurra Estuaries The depressed levels of

oxygen observed in the reach between the Port of Cork and Blackrock Castle in the

period 1999-2003 were again evident during the latest surveys. However, the level of

oxygen depletion recorded during the current period at 51.5 per cent, is a substantial

improvement on levels measured in the periods 1995-1999 and 1999-2003 when levels

were only 11 and 31 per cent, respectively. Ammonium levels have also declined since

the last period with the median and maximum ammonium concentration having

declined by 30 and 40 percentage points, respectively. In terms of classification the

estuary is still intermediate having also failed the nitrogen criterion due to elevated

levels in winter.

There has also been a marked improvement in the water quality status of Lough Mahon,

which is now classified as intermediate, having previously been categorised as

eutrophic in the period 1999-2003. Chlorophyll concentrations, which were elevated in

the previous period, were within acceptable levels, although there was some evidence of

excessive phytoplankton activity as indicated by supersaturated oxygen levels recorded

in July 2006. In general dissolved oxygen levels have continued to improve, and only

marginally failed to meet the undersaturation criterion, representing a considerable

improvement on previous periods. The winter nitrogen criterion was breached, as was

the case in the previous assessment.

The improvements observed in the Lee estuary and Lough Mahon are likely to be the

result of the Cork Main Drainage Project which was completed towards the end of

2004. Discharges of raw sewage, which had previously entered the lower Lee estuary

and Lough Mahon, are now redirected to the waste water treatment plant at


4-20

Carrigrennan on Little Island where they receive secondary treatment before being

discharged into Lough Mahon.

As in the previous assessment the Owenacurra estuary was confirmed as eutrophic due

in large measure to the high levels of nitrogen inflowing from the Owenacurra River.

On a single sampling occasion in the summer of 2005 surface water discolouration

resulting from a phytoplankton bloom of the dinoflagellate species Glenodinium

foliaceum was observed. Oxygen supersaturation values recorded during this bloom

event were as high as 274 per cent – the second highest dissolved oxygen value

recorded in any of the water bodies assessed during the current period. At this level of

saturation it is probable that noctural phytoplankton respiration would have resulted in

very low or hypoxic oxygen concentrations during the hours of darkness.

Finally, elevated nitrogen levels, most likely from upstream sources, resulted in Cork

Harbour being classified as intermediate as was the case in the previous assessment.

Killybegs Harbour and McSwyne’s Bay The low levels of dissolved oxygen observed

in Killybegs Harbour and McSwyne’s Bay in the period 1999-2003 have persisted and

as a result both water bodies are again classed as intermediate in the current assessment.

Depressed levels of dissolved oxygen at 50-60 per cent of what is considered normal

have been persistently observed in the harbour since monitoring began in 1995. The

main causes are discharges from Killybegs sewage treatment plant, which can be

variable due to intermittent activity in the fish processing industry, and the release into

the harbour of organically rich material associated with the landing and cleaning of fish.

Another contributing factor is the absence of any significant flushing or strong tidal

currents within the harbour. These stagnant conditions prevent the mixing of oxygen-

rich surface waters with bottom waters with the result that these can become

deoxygenated in the presence of biodegradable waste and organically rich sediments.

Deoxygenation conditions have also been observed in the deeper waters of McSwynes

Bay. During a number of surveys carried out in the summers of 2002, 2003 and 2005,

bottom dissolved oxygen concentrations, in waters over 30 m deep, were found to be as

low as 30-50 per cent of full saturation. Again it is unlikely that these levels can be


4-21

wholly explained by the presence of anthropogenically derived biodegradable material

as BOD concentrations recorded during the period 2002-2006 were low with 95 per cent

of the samples analysed having BOD levels less than 2.0 mg/l O2. While other sources

of pollution cannot be ruled out it would seem that the physical characteristics of

McSwyne’s Bay, which can display significant thermal stratification in summer, could

also partly explain the low oxygen levels. The effects of stratification in inhibiting the

exchange of oxygen between surface and bottom waters, with the result that bottom

water can become depleted in respect of surface values, has also been observed in a

number of other sea areas (Rabalais and Turner, 2001).

Allowing for the possibility that the deeper waters of McSyne’s Bay and Donegal Bay

may have naturally low levels of dissolved oxygen, additional consideration may need

to be given to understanding the environmental impact from the new Killybegs

sewerage treatment plant discharge. Construction of the plant, which will have one of

the highest population equivalent discharges in Ireland, is scheduled to commence in

2008. Additional monitoring, in the vicinity of the discharge, may be required to fully

assess any potential impacts it may have on ambient dissolved oxygen levels.

Swilly Estuary As in the previous reporting period, marked deoxygenation and

excessive phytoplankton production was again observed in the Upper Swilly estuary,

and oxygen levels were also in breach of the supersaturation criterion. Nutrient

concentrations in the estuary and in the inflowing Swilly river were well below their

respective criteria indicating that the observed disturbance to both oxygen and

chlorophyll is more than likely attributable to excessive enrichment from Letterkenny

waste water treatment plant which discharges to the upper reach of the estuary. This

view is also confirmed by the elevated BOD concentrations of 8.1 mg/l O2 (95

percentile) recorded in the estuary. This was the highest 95 percentile BOD statistic

recorded in any of the water bodies assessed during the current period.

The field observations confirm that the poor operational performance of Letterkenny

waste water treatment plant, which consistently fails to meet the required discharge

standards (EPA, 2007) is having an adverse effect on the water quality of the estuary.

This is an unsatisfactory situation and adequate waste water treatment should be

provided as a matter of urgency. As indicated in the previous report, in addition to


4-22

improving effluent quality, consideration may also need to be given to relocating the

treatment plant outfall from its existing location, which would appear to have very

limited diluting capacity, to a more suitable site.

Argideen Estuary and Courtmacsherry Bay In 2006 the distribution of macroalgae in

the Argideen estuary was formally assessed by the EPA using a new classification

system which is being developed for the purposes of the Water Framework Directive

(Box 1). The outcome of the assessment has confirmed the abundance and coverage of

macroalgae in the estuary cannot be considered normal. It is therefore likely that the

estuary will be classified as less than good ecological status under the WFD.

Winter Nutrient Monitoring in the Irish Sea and Celtic Sea

Since 1990, the Marine Institute has been carrying out intensive monitoring of nutrient

levels in the western Irish Sea and, latterly, the eastern Celtic Sea at the time of minimal

biological activity (January-February). While no data on summertime chlorophyll and

dissolved oxygen levels are available for these waters, nutrient data collected over the

period 2002 to 2006 by the Marine Institute indicate no instances of excessive nutrient

enrichment. This result is consistent with the main finding of the Marine Institute’s

review of their data for the period 1990 to 2000, which found little evidence of elevated

nutrient levels in the coastal and offshore waters of the western Irish Sea and eastern

Celtic Sea (McGovern et al. 2002). Over the review period there were indications of a

decrease in both oxidised nitrogen and orthophosphate in all regions with the exception

of total oxidised nitrogen in the southwest Irish Sea where a 5 percentage point increase

was indicated.

Nutrient data collected between 2001-2005 were used to assess the trophic status of the

coastal and offshore areas of the western Irish Sea and eastern Celtic Sea as part of the

OSPAR strategy to combat eutrophication in the waters of the North-east Atlantic. A

key element of this strategy is the Common Procedure, which establishes a framework

for each contracting party to assess the trophic status of their parts of the OSPAR

maritime area.

As in the previous assessment there was little evidence of elevated nutrient levels in any

of the areas assessed. Nutrient concentrations were consistently below the OSPAR


4-23

thresholds and the ratios between the different nutrient elements, which can indicate

anthropogenic nutrient disturbance, were also generally below their respective OSPAR

thresholds. These findings together with the recent review of Gowen et al. (2008),

which found little evidence of disturbance in oxygen conditions (except the seasonally

isolated western Irish Sea bottom water) or phytoplankton community structure or

production, resulted in these areas being designated as non-problem areas with regard to

eutrophication.

MONITORING OF TOXIC CONTAMINANT LEVELS IN ESTUARINE AND

COASTAL WATERS

The Marine Institute monitors the levels of priority hazardous substances in a range of

commercial fish species landed at Irish ports and also in shellfish from selected sites

around the Irish coast. These are substances, such as mercury, that have been identified

as being of particular concern to the marine environment and to consumers of seafood.

Levels of such substances in fish and shellfish are a good indicator of contamination in

the marine environment as a whole. Inter alia, the monitoring is part of Ireland’s

contribution to the Joint Assessment and Monitoring Programme (JAMP) of the

OSPAR Convention.

Metals in Fish Landed at Irish Ports

In accordance with the requirements of European legislation, the Marine Institute

samples a range of fish species landed at five major Irish ports (Castetownbere,

Rossaveal, Killybegs, Dunmore East and Howth) on an annual basis. The samples are

tested for mercury as well as other trace metals, such as cadmium and lead, and

chlorinated hydrocarbons. European Commission Regulation (EC, No. 1881/2006:

consolidating Regulations EC, 2001, 2002 and 2005) has set maximum levels for

mercury, cadmium and lead in fish. The lowest maximum limits are 0.05 mg kg –1 and

0.5 mg kg –1 wet weight for cadmium and mercury respectively and the maximum limit

for lead in all finfish is set as 0.3 mg kg –1. Previously, a general level of 0.2 mg kg –1

had applied with a higher level of 0.4 mg kg –1 for certain selected species.

In 2004, 2005 and 2006 all results complied with the EC maximum limits set for lead,

cadmium and mercury. The highest concentrations of mercury were recorded for two

samples, both of spurdog (Squalus acanthias), and while these were above 0.5 mg kg-1


4-24

wet weight, they were below the higher limit of 1 mg kg –1 wet weight that applies to all

species of shark, including spurdog. There are no internationally agreed standards or

guidelines available for other trace metals (chromium, copper, nickel, silver and zinc) in

fishery products but the levels of these contaminants between 2004-2006 were well

below the strictest standard or guidance value for fish tissue applied by individual

contracting parties to the OSPAR Convention.

Environmental Contaminants in Shellfish Concentrations of environmental

contaminants such as metals, hydrocarbons and persistent organic pollutants in bivalve

molluscs are very good indicators of ambient water quality with respect to these

parameters. The Marine Institute monitors contaminants in mussels and oysters from

shellfish growing waters but supplements this with additional samples from areas where

shellfish are not harvested to give a more representative picture of the status of waters

along the Irish coast (see the section below on shellfish waters).

Dioxins, Polychlorinated Biphenyls and Brominated Flame Retardants in Fish

Polychlorinated biphenyls (PCBs) are a group of extremely stable aromatic chlorinated

compounds. They have excellent electrical and heat transfer properties, which led to

their widespread use in a variety of industrial, commercial and domestic applications.

The production and use of PCBs has been discontinued in most countries, due to

concern about their toxicity and persistence, but large amounts remain in electrical

equipment, plastic products, buildings and the environment.

The term “dioxins” covers a group of 75 polychlorinated dibenzo-p-dioxin (PCDD) and

135 polychlorinated dibenzofuran (PCDF) congeners, 17 of which are of toxicological

concern. They have no known commercial applications and arise as by-products in

combustion and certain industrial processes. Dioxins are highly resistant to degradation

processes in the environment and consequently persist where they have been deposited.

There are 12 PCB congeners of the 209 PCB congeners which have a "coplanar" or

dioxin-like structure with the two bi-phenyl rings lying in the same plane. These show

similar toxicological properties to dioxins and are often termed "dioxin-like PCBs".

Brominated flame retardants (BFRs) are a diverse group of high production volume

chemicals characterised by their bromine content and used to retard the combustibility


4-25

of commercial goods. These include hexabromocyclododecane (HBCD) and

polybrominated diphenyl ethers (PBDEs) that are added to polymers, plastics, electronic

equipment and to textiles to reduce the risk of fire. The EU banned two PBDEs

formulations, pentaBDE and octaBDE in 2004, however, decaBDE is still in use. Other

BFRs include Tetrabromobisphenol A (TBBPA), which is the primary flame retardant

used in electronic boards. PBDEs are included as priority hazardous substances in the

list of such chemicals under the Water Framework Directive.

In 2004 the Food Safety Authority of Ireland, in collaboration with the Marine Institute

and Bord Iascaigh Mhara, carried out a surveillance study of levels of dioxins (PCDDs),

furans (PCDFs), PCBs and BFRs, specifically PBDEs and HBCD, in a variety of fish

species and fishery products, including fresh and processed products available on the

Irish market (Tlustos et al., 2006). For this survey a total of 70 samples were collected

comprising the following species and retail groupings: farmed Atlantic salmon, wild

Atlantic salmon, fresh herring, fresh mackerel, fresh tuna, fresh shellfish, smoked

farmed salmon, canned salmon, canned tuna, canned herring, canned sardines and

canned mackerel. EC legislation was set for PCDDs and PCDFs and for the sum of

PCDDs and PCDFs and dioxin like PCBs (expressed as World Health Organisation

Toxic Equivalents) under Regulation 466/2001 as amended and subsequently

consolidated under Regulation 1881/2006.

The study showed that the levels of PCDDs and PCDFs and the levels of the sum of

PCDDs/PCDFs and dioxin-like PCBs in Irish fish and fishery products available on the

Irish market were well below EC legal limits. Concentrations of BFRs were also low.

The mean PBDE concentrations ranged from less than 0.31 to 3.71 µg/kg whole weight

in canned tuna to farmed salmon, respectively. Although there are no acceptable daily

intake (ADI) or maximum limits set for PBDEs or HBCD, the levels of these

contaminants found in the study were low, and are very unlikely to present a health risk

to Irish consumers.


4-26

QUALITY OF SHELLFISH AND SHELLFISH GROWING WATERS (H1)

Monitoring of Shellfish Waters and Production Conditions for Shellfish

The Department of Communications, Marine & Natural Resources (DCMNR) was until

very recently the competent authority in Ireland responsible for classifying shellfish

production areas as required under Directive (91/492/EEC) and by the 1996 Regulations

(S.I. No. 147, 1996). This role is now undertaken by the new Sea-Fisheries Protection

Authority (SFPA) established in January 2007. The Directive and subsequent

amendments, lay down the health conditions for the production and placing on the

market of live bivalve molluscs.

Although the classification is mainly based on the bacteriological quality of shellfish

(Table 4), other criteria are also taken into account for the assessment including the

following:

(a) they must not contain toxic/objectionable compounds in such quantities that the

calculated dietary intake exceeds the permissible daily intake (PDI) or that taste is

impaired.

(b) the upper limits as regards the radionuclide contents must not exceed those laid

down for foodstuffs.

(c) the total Paralytic Shellfish Poison (PSP) content in the edible parts must not exceed

80 microgrammes per 100 grams of shellfish flesh in accordance with the biological

testing method.

(d) the customary biological testing methods must not give a positive result to the

presence of Diarrhetic Shellfish Poisoning (DSP) in the edible parts of the shellfish.

The proportion of shellfish production areas in each classification category in the

current assessment period and in earlier years is presented in Table 5, while the

classification results for 2006 is shown graphically in Figure 6.

In recent years the lowest proportion of areas assigned to Class A, at 21 per cent,

occurred in 2003. This marked a substantial reduction on the 1991-1994 period when

over 50 per cent of the areas assessed were in this category. In 2005, the proportion of

areas in this category increased to 30 per cent, a substantial increase on 2003 levels,

although this was reversed somewhat in 2006 when levels fell back to 24.5 per cent. It


4-27

was also noted that no Class C water were reported in 2004, 2005 and 2006. This is an

improvement from the situation recorded in 1987-1990 when 12 per cent of the sites

monitored were assigned to Class C. A full list of the sites with their classification in

2006 is given in Appendix IV.3. This list can also be obtained on the SFPA website at

www.sfpa.ie.

The Directive (79/923/EEC) on the quality required of shellfish waters was transposed

into Irish law by Regulations made in 1994 (S.I. No. 200 of 1994). In 2006 these

regulations were revoked and replaced by the quality of shellfish waters Regulations

(S.I. No. 268 of 2006) that established mandatory limits and guide values for designated

shellfish waters and also specified allowable guidance concentrations of various

parameters in shellfish flesh. Under the national regulations the sites designated as

shellfish areas were: Clarinbridge, Kilkieran Bay, Killary Harbour, Mulroy Bay, Bantry

Bay, Glengarriff Harbour, Roaring Water Bay, Aughinish Bay in Co. Galway,

Cromane, Maharees, Kilmakilloge, Carlingford Lough, Clew Bay and Bannow Bay.

Table 4

Summary of scheme of classification of shellfish production areas operated by

SFPA under Regulation (EC) No 854/2004.

Classification Microbiological Standard Treatment Required

A1 <230 E. coli per 100g flesh and

intra-valvular liquid. 2

May go direct for human

consumption

B <4,600 E. coli per 100g flesh

and intra-valvular liquid. 2

Must be depurated or relayed to

meet class A

C <46,000 E. coli per 100g flesh

and intra-valvular liquid.2

Relaying for a period of at least

2 months prior to sale 1 Shellfish going directly for consumption must also be free from Salmonella spp. 2 Using Five tube, three dilution MPN test In accordance with the monitoring requirements of this legislation and the 1991

Directive, the Marine Institute collected water and shellfish (blue mussel, Pacific and

native oysters) samples from 30 sites in 2004, 36 in 2005 and 30 in 2006. In addition to

the major growing areas, which included the above 14 designated shellfish waters, other

production areas have been sampled including Wexford Harbour, Arthurstown

(Waterford), Dungarvan, Cork Harbour, Kenmare Bay, Cromane (Castlemaine), Tralee

Bay, Aughinish (Limerick), Ballysadare and Lough Foyle.


4-28

Table 5

Total numbers of shellfish sites sampled in eight periods between 1991 and 2006

with proportions (%) in each class. (Note that percentages do not add to 100 as

sites with more than one class are omitted) 2006 2005 2004 2003 2000 1998-99 1991-94 Total

Number 571 572 613 584 615 586 587

Class A 24.5 29.8 22 21 34 24 55

Class B 56.1 54.3 60.6 62 54 60 29

Class C 0 0 0 2 2 2 0

1 10 areas were classed as partly A and B; 1 as B and C. 2 8 areas were classed as partly A and B; 1 as B and C. 3 8 areas were classed as partly A and B; 1 as B and C. 4 8 areas were classed as partly A and B; 1 as B and C. 5 4 areas were classed as partly A and B; 1 as partly A, B and C; 1 as B and C. 6 6 areas were classed as partly A and B; 1 as partly A, B and C; 1 as B and C. 7 5 areas were classed as partly A and B; 1 as partly A, B and C; 1 as B and C.

The levels of cadmium, lead and mercury in shellfish tissues were generally well within

EU limits for the period 2004-2006. In Castlegregory, cadmium levels in oyster (Ostrea

edulis) samples were close to the limit of 1.0 mg/kg for that metal (2004: 0.93 mg/kg,

2005: 0.95 mg/kg and 2006: 0.78 mg/kg). Elevated levels of cadmium were also

detected in a mussel (Mytilus edulis) sampled in Tralee Bay, Fenit (0.78 mg/kg). In

2006, an elevated level of chromium was detected in one mussel sample from inner

Lough Swilly (2.32 mg/kg) at a concentration not seen in previous years (e.g. 0.14

mg/kg in 2005). For the other trace metals measured, all concentrations were well

below the strictest values listed thus confirming the unpolluted nature of Irish shellfish

and shellfish-producing waters (Marine Institute, 2007)

Seawater samples were collected from the 14 designated shellfish areas twice annually

and analysed for trace metals and organochlorines. All organohalogens (PCBs and

pesticides) results were below limits of detection (Marine Institute, 2007). The metal

results varied substantially as would be expected for seawater samples, and a number of

samples exceeded current Irish standards (Water Quality (Dangerous Substances)

Regulations (S.I. No. 12 of 2001)). Individual results do not in themselves imply a

breach as these standards apply as annual average concentrations. However, no samples

exceed the Imperative values (maximum allowable concentrations) for shellfish waters

as set out in SI 268 of 2006.


4-29

Figure 6. Classification of shellfish production areas 2006 (Source DCMNR).

Occurrence of Shellfish Biotoxins

The Marine Institute, which is the national reference laboratory for shellfish biotoxins,

is contracted by the Food Safety Authority of Ireland (FSAI) to undertake the

monitoring of biotoxins in shellfish intended for human consumption. The Institute has

operated a national phytoplankton and biotoxin monitoring programme for the detection

of these naturally occurring marine organisms and biotoxins since 1984.

3

5

6

8910

11

12

13

1415

16

19

23

24

25

28

3334

37

42

45

51

52

55 57

1

20

21

22

29

30

36

38

39

41

44

46

50

53

56

2

4

1718

2627

31

32

35

40

47

48

49

54

7

Class A

Class B

Production areas with A and B classification

Production areas with B and C classification

No. Production Area No. Production Area No. Production Area No. Production Area No. Production Area No. Production Area

1 Carlingford 11 Dungarvan 21 Bantry 31 Kilkieran 41 Killala 51 Dungloe

2 Dundalk 12 Ballymacoda 22 Kenmare 32 Mannin 42 Ballysodare 52 Gweedore

3 Boyne 13 Cork 23 Valentia 33 Clifden Outer 43 Sligo 53 Sheephaven

4 Gormanston 14 Oysterhaven 24 Castlemaine 34 Clifden Inner 44 Drumcliff 54 Mulroy

5 Skerries 15 Kinsale 25 Tralee 35 Streamstown 45 Donegal 55 Swilly

6 Malahide 16 Baltimore 26 Carrigaholt 36 Ballinakill 46 Inver 56 Tra Breaga

7 Wexford 17 Sherkin North 27 Poulnasherry 37 Killary 47 McSwynes 57 Foyle

8 Ballyteigue 18 Sherkin Kinish 28 Ballylongford 38 Clew 48 Loughros

9 Bannow 19 Roaringwater 29 Kilrush 39 Achill 49 Gweebarra

10 Waterford 20 Dunmanus 30 Galway 40 Blacksod 50 Traweenagh


4-30

In Ireland, the occurrence of shellfish contamination is variable from year to year, with

most of the resultant closures of production areas being attributed to Dinophysis species,

the causative organism of DSP. However, other toxic species, such as Pseudo-nitzschia

(Amnesic Shellfish Poisoning (ASP)), Alexandrium (PS P) and Protoperidinium species

(Azaspiracid Shellfish Poisoning (AZP)) are also problematic.

The shellfish production areas around the coast of Ireland are monitored on a weekly or

monthly basis for phytoplankton and the presence of marine biotoxins. Where biotoxins

are detected, the production area is closed and harvesting prohibited until the danger of

toxicity has passed. Such closures are essential to protect human health and the

reputation of the Irish shellfish industry. Total production of shellfish was valued at

€63.2 million in 2006, mostly from coastal rural areas where it represents a significant

contribution towards the local economy. Closures of shellfish-growing areas as a result

of biotoxin contamination are common in the summer and autumn when toxin-

producing algae are present.

Traditionally, molluscan shellfish were only taken for consumption between the months

of September and April but are now produced and consumed throughout the year.

In 2004, which was considered a low toxicity year, less then four per cent of shellfish

tested were positive for DSP. Levels of AZP were also low and did not lead to the

closure of any shellfish production areas. The toxicity profile in 2004 was similar to

2002 and 2003. However, in 2005 and 2006 there were prolonged closures due to the

presence of DSP and AZP toxins in coastal waters around Ireland. There were also

localised closures in Cork Harbour due to PSP during the last two weeks of June 2006.

In these years there was a significant increase in shellfish testing positive for the

presence of DSP toxins with 17.5 per cent and 16.4 per cent of bioassays proving

positive in 2005 and 2006, respectively. Overall, and simply in terms of the proportion

of samples testing positive for the presence of toxins, 23 per cent of all mussels tested

were positive for toxin in 2005 and this increased to 29 per cent in 2006.

The extended toxicity periods in 2005 were mainly due to the presence of three toxins,

ASP (South-west, April/May), DSP (Nationally, May-Sept) and AZP (Nationally, Sept-

Dec). This resulted in prolonged closures in 38 sites, some for several months (Clarke


4-31

et al., 2007). The toxicity in 2006 was due to AZP (Nationally, Jan-May), DSP (South-

west and West, Jun-Sept) and PSP (Cork Harbour, June). The AZP toxicity in early

2006 extended from a toxic event that began in 2005.

Box 2. An Exceptional Dinoflagellate (Karenia mikimotoi) Bloom in Irish Waters

During the summer of 2005 there was a very extensive bloom of the dinoflagellate Karenia mikimotoi

along Ireland’s western seaboard. The onset of the bloom began in late May/early June off the north-west

coast and dissipated in July. The bloom was very intense and resulted in water discolouration and

foaming in coastal bays. This bloom was succeeded by a second bloom of the same species in the south-

west in late July. This latter event was not as persistent as the bloom in the north and dissipated during

August. Concurrent with these blooms were mass mortalities of vertebrates and invertebrates along the

entire western seaboard. Benthic organism mortalities were more severe than in previous blooms and a

visible effect of the bloom was the presence on beaches of dead heart urchins (Echinocardium cordatum)

and lugworms (Arenicola marina).

During this time, low wind speeds and calm conditions allowed the bloom to grow. The onshore wind led

to an accumulation of high numbers of dinoflagellate cells in coastal embayments and along the shores of

the western seaboard. Cell numbers reached over 3 million cells/L in Donegal Bay in June while high

concentrations of up to 3.7 million cells/L were observed in the Glenbeigh area of Dingle Bay in July.

The extent of these blooms was also apparent from satellite images during the first half of June along the

western seaboard. Also high chlorophyll levels were visible in Dingle Bay in August. These high

chlorophyll levels correlated with the high cell numbers observed at those times. This species has

bloomed in Irish waters in the last 30 years but the scale of mortality associated with the 2005 bloom had

not been recorded before.

A detailed report on this exceptional bloom has been published by the Marine Institute (Silke et al., 2005)

and is available online at: www.marine.ie

For the first time in Ireland, levels of domoic acid (DA), the neurotoxin that causes

ASP, were found above the regulatory limit in mussels and oysters. This resulted in a

number of closures in the south-west and less so in the north-west in April 2005.

Domoic acid is typically only found in scallops in Ireland and previously there had been

one record of levels in mussels over the regulatory limit in Donegal in 2002. The 2005

event was due to a monospecific bloom of the diatom Pseudo-nitzschia australis.

At present, there is little evidence to suggest that the variable occurrence of toxin

emitting species, or associated toxicity in shellfish, in Irish waters, is related to nutrient

enrichment or other forms of anthropogenic pollution. In fact, studies suggest that


4-32

blooms originate offshore and are advected inshore by the wind (Raine et al., 1993,

Raine and McMahon, 1998; O’Boyle et al., 2000). The occurrence of an exceptional

bloom of the dinoflagellate Karenia mikimotoi in Irish waters in the summer of 2005

more than likely resulted from the advection inshore of an established offshore

population (see Box 1.)

QUALITY OF BATHING WATERS

The monitoring of the water quality at designated bathing areas is undertaken in

accordance with the provisions of the quality of Bathing Water Regulations 1992 (S.I.

No 155 of 1992) and subsequent amendments. These Regulations transposed the

requirements of the EC Directive concerning the quality of bathing waters

(76/160/EEC). The purpose of the directive is to ensure that the quality of bathing water

is maintained and, where necessary, improved so that it complies with specified

standards designed to protect public health and the environment.

Local authorities are responsible for bathing water quality in their area including

monitoring and making information available to the public during the summer season.

The role of the EPA is to collate the results of monitoring which are forwarded to the

European Commission for inclusion in the European-wide compendium report

published annually. The EPA also publishes an annual national bathing water report

which is released prior to the start of the following bathing season (EPA, 2007b).

There are currently 131 designated bathing areas in Ireland comprising both seawater

(122) and freshwater (9) sites. Monitoring commences in mid May and is undertaken

by the competent local authority fortnightly during the bathing season, which extends

from 1st June to the end of August each year. The minimum number of samples to be

taken during the season is therefore seven but more frequent sampling may be carried

out where:

• the results indicate, or an investigation finds, that a deterioration in the water quality

has taken place or

• there appears to be a discharge of substances likely to lower the quality of the

bathing waters.


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Compliance Assessment

While the sampling and analysis criteria for bathing waters is largely similar for both

national and EU legislation there are differences in the way in which compliance with

the results of these parameters is assessed.

The National Regulations stipulate that each sample obtained must be analysed for the

following 8 microbiological and physicochemical parameters:

Total coliforms Surface active substances

Faecal coliforms Phenols

Colour Transparency

Mineral oils Tarry residues, floating materials

Under certain circumstances, in particular where there has been a deterioration of water

quality, both the frequency of monitoring and range of analytes must be increased.

Similarly, where bathing water quality is found to be consistently of a very good

quality, the monitoring frequency may be reduced to a minimum of four times during

the bathing season.

In addition to the eight parameters listed under national compliance, further parameters

may also be assessed if there are grounds for believing, or an investigation shows, that

the water quality has deteriorated in respect of the particular parameter(s). These

additional parameters include faecal streptococci, Salmonella and Enteroviruses. Also,

bathing areas in Ireland are monitored regularly for faecal streptococci, as required

under the Blue Flag Scheme. Local Authorities must report the results of sampling to

the EPA at the end of each bathing season. The Agency interprets compliance with the

Regulations based on all of the parameters that are required to be sampled and analysed.

The parameters required to be sampled and analysed under the directive are the same as

those prescribed under the National Regulations. However, unlike national compliance,

which includes all parameters, EU bathing water compliance is based on a sub-set of

these parameters

The five parameters considered for EU compliance purposes are:


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• Total coliforms

• Faecal coliforms

• Mineral oils

• Surface-active substances

• Phenol

During the bathing season, the water quality at each designated point must be assessed

in accordance with specified standards. Three types of standards have been established

under European and national legislation:

Mandatory Values are values which must be observed if the bathing area is to be

deemed compliant with the directive.

Guide Values are more stringent than the mandatory values and can be regarded

as quality objectives which all bathing sites should endeavour to achieve.

National Limit Values are additional standards set by Ireland for a number of

parameters (dissolved oxygen, total coliforms, faecal coliforms, faecal

streptococci).

Seawater Bathing Water Compliance Results 2004-2006

In general, the standard of water quality at marine bathing areas in Ireland has remained

high. During each year of the review period (2004-2006), over 96 per cent of the sites

monitored complied with the minimum mandatory standards laid down by EU

legislation. The proportion of sites complying with the more stringent EU guideline

standards rose during the review period from 88 per cent in 2004 to 91 per cent in 2006.

These results are an improvement over the previous 2001-03 reporting period where the

maximum proportion of sites complying with the more stringent values was 84 per cent.

In addition to the standards for total and faecal coliforms set out in the EU Bathing

Water Directive, national standards include an additional microbial parameter, namely

faecal streptococci. Average compliance over this three-year reporting cycle with these

national standards was 79.3 per cent compared with 79.6per cent in the previous review

period.


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The number of sites failing the minimum mandatory standards between 2001 and 2006

is shown in Table 6. The location and compliance status of all 131 designated bathing

areas sampled during 2006 are shown in Figure 7 (this figure includes the freshwater

bathing areas). Overall, Ireland’s bathing water compares very favourably with that in

other EU Member States.

Yet, while the quality of water at designated bathing sites is high, the number of sites

remains low in comparison to other European countries. To ensure adequate protection

of those using bathing areas, the current number of 131 designated sites needs to be

increased. The Agency’s Strategic Framework “2020 Vision” recognises the

importance of this issue and has proposed a target to increase the number of designated

bathing sites to 160.

Persistent Failures

Over this reporting period a number of designated sites reported repeated failures with

bathing waters standards. The poorest performers in terms of overall compliance with

the bathing water standards were: Balbriggan and Sutton-Burrow, Co. Dublin; Clifden

and Spiddal, Co. Galway; and Ardmore, Co. Waterford.

Table 6

Number and location of bathing sites failing the minimum mandatory standards

between 2001 and 2006. Number of sites failing each year is given in parenthesis. Year 2001 (3) 2002 (3)

Location Clifden, Co. Galway; Merrion Strand and Sandymount, Co. Dublin

Ardmore, Co. Waterford; Brittas Bay North and Brittas Bay South, Co. Wicklow

Year 2003 (4) 2004 (3)

Location Balbriggan, Co. Dublin; Bray, Co. Wicklow; Keem, Co. Mayo; Spiddal, Main Beach, Co. Galway

Balbriggan and Skerries, Co. Dublin; Dunmore East Main Strand, Co. Waterford

Year 2005 (5) 2006 (4)

Location Merrion Strand and Sutton-Burrow, Co. Dublin; Clifden and na Forbacha, Co. Galway; and Ardmore, Co. Waterford

Balbriggan and Malahide, Co. Dublin; Clifden, Co. Galway; Dunmore East Main Strand, Co. Waterford


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Figure 7. Bathing water quality in 2006.

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Dublin & Northeast Coast

Galway Bay Area

Northwest Donegal

Non-Compliant with EU Mandatory and Guide Values

Compliant with EU Mandatory Values

Compliant with EU Guide ValuesNo. Location

1 Mountshannon

2 Ballyallia

3 Ballycuggeran

4 Spanish Point

5 Kilkee

6 White Strand, Doonbeg

7 Lahinch

8 Bishopsquarter

9 Fanore

10 Cappagh Pier, Kilrush

11 White Strand, Miltown Malbay No. Location No. Location No. Location No. Location No.

12 Coolmaine 32 Portsalon 52 Malahide 72 Banna Strand 92 Dooega, Achill 112

13 Redbarn 33 Rossnowlagh 53 Loughshinny 73 Rossbeigh, White Strand 93 Keem, Achill 113

14 Barley Cove 34 Lisfannon 54 Rush, South Beach 74 Inch 94 Keel, Achill 114

15 Tragumna 35 Marble Hill 55 Portrane 75 Ballyheigue 95 Doogort 115

16 Garryvoe 36 Portnablagh 56 Killiney 76 Ballybunion South 96 Louisburg, Silver Strand 116

17 Garrettstown 37 Drumatinny 57 Seapoint 77 Ventry 97 Carrawmore 117

18 Fountainstown 38 Port Arthur 58 Tra na bhForbacha, Na Forbacha 78 Inny, Waterville 98 Bertra 118

19 Youghal, Main Beach 39 Fintra 59 Tra Chaladh Finis, Carna 79 Maharabeg 99 Mulranny 119

20 Inchdoney 40 Naran, Portnoo 60 Ceibh an Spideil 80 Derrynane 100 The Harbour, Clare Island 120

21 Claycastle 41 Culduff 61 Cill Mhuirbhigh, Inis Mor 81 Fenit 101 Golden Strand, Achill 121

22 Garrylucas, White Strand 42 Stroove 62 Goirtin, Cloch na Ron 82 White Strand, Caherciveen 102 Rinroe, Carratigue 122

23 Warren 43 Carrickfinn 63 Clifden 83 Ballybunion North 103 Mullaghroe 123

24 Owenahincha 44 Sandymount Strand 64 Tra na mBan, An Spideal 84 Castlegregory 104 Elly bay, Belmullet 124

25 Murvagh 45 Dollymount Strand 65 Traught, Kinvara 85 Kells 105 Killala, Ross Strand 125

26 Killahoey 46 Merrion Strand 66 Loughrea Lake 86 Ballinskelligs 106 Louisburg, Old Head Beach 126

27 Ballyhernan 47 Sutton, Burrow Beach 67 Tra an Doilin, An Cheathru Rua 87 keeldra 107 Laytown/Bettystown 127

28 Downings 48 Skerries 68 Portumna 88 Seapoint 108 Mullaghmore 128

29 Rathmullan 49 Balbriggan 69 An Tra Mor, Coill Rua, Indreabhan 89 Clogherhead 109 Enniscrone 129

30 Lady's Bay 50 Donabate 70 Silver Strand 90 Shellig Hill/Templetown 110 Rosses Point 130

31 Bundoran 51 Portmarnock 71 Salthill 91 Port, Lurganboy 111 Bonmahon 131


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New Directive Concerning the Quality of Bathing Water (2006/7/EC)

In the 1970s, the importance of having adequate protection for both bathers and the

environment was highlighted. This resulted in the adoption of the Bathing Waters

Directive (76/160/EEC), which was one of the first pieces of European environmental

legislation. Since then significant advances have been made in terms of both technical

and environmental management of water quality. The European Commission put

forward a proposal in 2002 for a new directive on bathing water quality. The aim of the

proposal was to tighten but simplify the health standards for bathing waters, improve

the management of bathing sites and the provision of public information, and to

streamline water quality monitoring programmes. The new Bathing Water Directive

(2006/7/EC) was adopted in February 2006 and transposed into Irish law (SI No. 79 of

2008) in March 2008.

The overall objective of the new Directive remains the protection of public health. In

addition, it also offers an opportunity to improve management practices at bathing sites

and to standardize the information provided to bathers across Europe. With regard to

monitoring, the new Directive reduces the number of measured parameters from the

previous nineteen to just two microbiological indicators of faecal contamination, E. Coli

and Intestinal Enterococci. This reduction is in recognition of the fact that faecal

material is the primary threat to swimmers. It also sets different standards for inland

and coastal bathing sites. The new Directive provides a classification system for water

quality at bathing sites - with sites being classified as either poor, sufficient, good or

excellent. In addition, classification at each site will be determined on the basis of three

or four years monitoring data instead of a single year’s result as is currently the case.

Thus, this new form of classification will be less susceptible to bad weather or one-off

incidents.

The new Directive also requires that bathing waters should be identified annually. This

should be done for the first time before the start of the 2008 bathing season.

Management plans for each site must be developed to minimize risks to bathers based

on an assessment of the sources of contamination that are likely to affect it. In addition,

the new Directive also aims not only to increase the amount of information available to

the public but also to actively and promptly disseminate this information through the

use of appropriate media, including the internet.


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The Blue Flag Scheme

The Blue Flag Scheme is an international voluntary eco-label to identify high quality

bathing water areas and marinas, administered in Ireland by An Taisce and

internationally by the Foundation for Environmental Education in Europe (FEEE). To

receive a Blue Flag, a designated bathing site, in addition to maintaining a high standard

of water quality, must meet specified objectives with regard to the provision of safety

services and facilities, environmental management of the beach area and environmental

education. The EPA has co-operated with An Taisce to check that all water quality

results obtained by both organisations each bathing season are comparable. The

analysis of bathing water in respect of the Bathing Waters Directive is separate from,

although complementary to, the International Blue Flag Scheme. The EPA also

participates in the National Blue Flag Jury, which assists in the initial assessment of the

Irish applicants for the Blue Flag Award. The award is based on the performance and

standards achieved during the previous bathing season. In 2004, 2005 and 2006,

respectively, 77, 79 and 81 blue flags were awarded to Irish beaches. The 2006 figure

was the highest number of Blue Flags ever achieved by Ireland.

RADIOACTIVITY MONITORING OF MARINE WATERS

Radioactivity monitoring of the Irish marine environment is undertaken by the

Radiological Protection Institute of Ireland (RPII). The RPII is the national

organisation with regulatory, monitoring and advisory responsibilities in matters

pertaining to ionising radiation in Ireland. Two recent reports on marine monitoring, for

the years 2003-2005 (Ryan, et al., 2007) and 2006 (Smith et al., 2007), cover the

present review period. Samples of fish and shellfish species were collected from

commercial landings at major Irish fishing ports and aquaculture areas. Particular

attention was given to collecting samples from the north-east ports of Carlingford,

Clogherhead and Howth, where the highest concentrations of Sellafield-derived

radionuclides have been found. Seawater, sediment and seaweed were also collected

from coastal sites while seawater and sediment samples were taken at offshore sites in

the western Irish Sea using the Marine Institute’s research vessel Celtic Voyager.

The dominant radionuclide being discharged from Sellafied continues to be Caesium-

137, accounting for approximately 60-70 per cent of the total radiation dose from


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Sellafield to the Irish population. The dose due to this radionuclide has declined

significantly over the last two decades corresponding to the reduction in discharges

from Sellafield.

The consumption of fish and shellfish from the Irish Sea continued to be the dominant

pathway by which anthropogenic radioactive contamination of the marine environment

resulted in radiation exposure of the Irish population. In the period covered by this

report (2004-2006) the mean annual committed effective dose to a heavy consumer of

seafood from the Irish Sea was 0.86 micro sieverts (µSv), which was similar to that

received over the 2001 – 2003 period.

The doses incurred by the Irish public as a result of anthropogenic radioactivity in the

environment are small by comparison with the doses received as a result of background

radiation. The doses from the consumption of fish and shellfish, for example, were

small compared with the estimated annual dose of 148 µSv received by the same

consumer due to the presence of the naturally occurring radionuclide polonium- 210 in

seafood and with the average annual dose to a person in Ireland from all sources of

radioactivity of 3620 µSv. In general, levels of radioactivity in the Irish environment

remained fairly constant over this reporting period and were broadly consistent with

levels reported during the previous period. Specifically regarding discharges from

Sellafield, the data reported here are consistent with the pattern of slow decline in

environmental concentrations that has been observed over a number of decades. The

RPII continue to emphasise that the levels of radioactive contamination present in the

marine environment, do not warrant any modification of the habits of people in Ireland,

either in respect of consumption of seafood or any other use of the amenities of the

marine environment.

Radiation doses to the Irish population resulting from discharges at Sellafield, on the

north-west English coast, are now very low and on the basis of current scientific

knowledge do not pose a significant health risk. Further reductions in these doses are

being pursued through the implementation of the OSPAR Strategy with regard to

Radioactive Substances. All signatories to the Strategy are committed to progressive

and substantial reductions in radioactive discharges from their facilities (Ryan et al.,

2007).


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In summary, the results of the RPII monitoring programmes between 2003 and 2005

show that, while the levels of anthropogenic radioactivity in the Irish environment

remain detectable, they are low and, on the basis of current scientific knowledge, do not

pose a significant risk to human health (Smith et al., 2007).

OIL POLLUTION INCIDENTS

Responsibility for the investigation of oil pollution incidents at sea rests with the Irish

Coast Guard (IRCG), a division now within the Department of Transport (DoT), as part

of its role in developing and co-coordinating an effective regime for marine pollution

response. Its functions in this respect are mandated through Government policy and

various pieces of national legislation, EU Directives and International Conventions.

The IRCG is responsible for incidents within the Irish Exclusive Economic Zone (EEZ),

formerly known as the Irish Pollution Responsibility Zone, an area (approx. 200,000

km2) stretching to 200 miles off the west coast and to the median line between Ireland

and the UK in Irish and Celtic Seas. The EEZ is an ecologically sensitive area with a

wide variety of fauna and flora and supports an active leisure industry, with a large

number of blue flag beaches, as well as commerce, including fisheries marine transport

and natural resources. Oil pollution of seawater arises chiefly from ballast water (mainly

from oil tankers); cargo tank washings (resulting from tank cleaning directly into the

sea); fuel oil sludge; engine room effluent discharges and in bilge-water (E. Clonan,

pers. comm.).

The major maritime incidents causing, or with a potential to cause, oil pollution that

occurred in 2004-2006 are summarised in Table 7. The largest marine pollution incident

in 2004 occurred in Cashla Bay, Galway where approximately eight tonnes of heavy

fuel oil leaked from an industrial estate along 1.6km of the shoreline.

IRCG received 59 pollution reports during 2004, 46 in 2005 and 44∗ in 2006, all of

which were investigated. An analysis of the incidents for the period showed that 20

∗ A total of 52 incidents were reported; however, in eight cases either no pollution was found or the threat of pollution was averted.


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percent of those in 2004, 28per cent in 2005 and 13 per cent in 2006 were likely to have

been caused by discharges from fishing vessels in the EEZ; in the majority of cases the

identity of the vessels could not be established. There were no prosecutions for illegal

discharges during the period 2004-2006. There were two incidents during 2006 where

prosecution was being considered depending on the evidence to be presented. Gathering

evidence of illegal discharges is often difficult. Provision of aerial surveillance

capability to detect illegal discharges and also assist in combating oil spillages would

greatly enhance the Coast Guard’s ability to prosecute offenders and monitor marine

pollution in the EEZ (E. Clonan, pers. comm.).

Table 7

Summary reports of larger maritime incidents involving the Irish Coast Guard

(IRCG) during 2004-2006 in chronological order (Source: E. Clonan, IRCG)

Location Date Vessel Incident

Outcome

Aughinish Alumina Jetty

10 December 2006

MT Cobalt Water

During the unberthing, it struck the pier and developed a 3-inch gash to the bunker tank resulting in the escape of approx 5 tonnes of heavy fuel oil.

Shannon Foynes Port Company was on site at the time and responded immediately. The Harbour Master instructed the Master of the vessel to transfer fuel from the bunker tank to bilge tanks. Harbour Master Shannon commenced deployment of booms and plug gash in the hull to stem the flow of oil. IRCG monitored closely and advised Harbour Master

Arklow Bank

21 July 2006

MV Ploudiv A Cargo Container (12,000 tonnes) ran aground.

No evidence of pollution. IRCG expert on board to monitor and advise. Vessel was refloated after 7 hours.

100 miles off west coast

February 2004

F/V Frank Bonefaas

IRCG Command System was activated.

Off Aranmore, Co. Donegal

October 2004

HMCS Chicoutimi

Suffered fire damage IRCG Command System was activated. No pollution resulted from this incident.

Kinsale Harbour

October 2004

M/V Seabrise

Driven on to rocks during gale force winds.

IRCG Command System was activated. Small diesel spill.


4-42

Mineral oils accounted for 95, 71 and 86 per cent respectively of the polluting material

observed in 2004, 2005 and 2006 and of these diesel and gas oils were the most

frequently identified. The overall geographical pattern for oil discharges indicated that

the majority of discharges occurred in smaller harbours and surrounding areas. Clusters

of slicks were identified in bays and near shore waters with 15 to 22 per cent of

pollution reported in the open sea in these three years. The percentage of slicks reported

in open sea should be treated cautiously as the Irish Coast Guard depends on reports

from shipping and commercial air traffic. There was an increase of oil spills from

offshore installations in 2006 due to an increase in offshore activity.

Work is being carried out to draft the national oil spill contingency plan (NCP) and 9 of

the 19 port contingency plans have been submitted to the IRCG for approval in

accordance with the Sea Pollution (Amendment) Act, 1999. The IRCG had issued oil

spill contingency plan guidelines to all maritime county councils who were instructed to

draw up contingency plans for the prevention and minimisation of damage arising out of

oil and other spillages on the coast. The Coast Guard also reviews and approves oil spill

contingency plans for mobile offshore drilling platforms intending to carry out drilling

work within the EEZ. Review and approval of these plans is ongoing.


4-43

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