Islands are at the forefront of climate change and the challenges it poses for the ocean. While its consequences are being measured all over the oceans and in all coastal areas, it is urgent to work with island territories to strengthen their capacities in terms of resilience and to develop strategies integrating ecological solidarity and preserving the quality of life for their populations. — In the light of effects of climate change that are already visible, such as extreme events, particularly in coastal areas, it is advisable to incorporate strategies for adaptation to these changes into territorial management, and this, right from the conception phase for responses. — The insular coastline is a zone with high stakes where ecological solidarity takes on all its meaning. In fact, maintaining ecological and economic balance depends on contributions of fresh water from the mountains. — Climate change will favour the settlement of new foreign species in the Mediterranean, of which monitoring must be maintained, as is currently the case with the Corsica Alien Species Network, to try to limit both ecological and economic impacts. — Corsica already disposes of a significant network of marine protected areas (MPAs) which has demonstrated its effectiveness in maintaining biodiversity and fishery resources. Extension of this network, envisaged within the context of the Regional Strategic Analysis, could incorporate spaces specifically devoted to the conservation of blue carbon sinks and alleviation of the impacts of climate change. — The extensiveness of natural insular areas and the reduced level of anthropogenic pressure suggest that Corsica could be a region with a positive carbon footprint: an evaluation of this footprint throughout the territory deserves to be undertaken. Climate change and the marine environment in Corsica Sensitivity of benthic habitats to the impacts of climate change. Conducted on 33 biocenoses and associations present from supralittoral to circalittoral zones, this report focuses on potential impacts caused by the rising sea level, the rise in water temperature, acidification and extreme events. Maximum Minimum
Transcript
Islands are at the forefront of climatechange and the challenges it poses for the ocean. While its consequences are beingmeasured all over the oceans and in allcoastal areas, it is urgent to work withisland territories to strengthen theircapacities in terms of resilience and todevelop strategies integrating ecologicalsolidarity and preserving the quality of lifefor their populations.— In the light of effects of climate change that are already
visible, such as extreme events, particularly in coastalareas, it is advisable to incorporate strategies foradaptation to these changes into territorial management,and this, right from the conception phase for responses.
— The insular coastline is a zone with high stakes whereecological solidarity takes on all its meaning. In fact,maintaining ecological and economic balance depends oncontributions of fresh water from the mountains.
— Climate change will favour the settlement of new foreignspecies in the Mediterranean, of which monitoring must bemaintained, as is currently the case with the Corsica AlienSpecies Network, to try to limit both ecological andeconomic impacts.
— Corsica already disposes of a significant network of marineprotected areas (MPAs) which has demonstrated itseffectiveness in maintaining biodiversity and fisheryresources. Extension of this network, envisaged within thecontext of the Regional Strategic Analysis, couldincorporate spaces specifically devoted to the conservationof blue carbon sinks and alleviation of the impacts ofclimate change.
— The extensiveness of natural insular areas and the reducedlevel of anthropogenic pressure suggest that Corsica couldbe a region with a positive carbon footprint: an evaluation ofthis footprint throughout the territory deserves to beundertaken.
Climate change and the marineenvironment in CorsicaSensitivity of benthic habitats to the impactsof climate change. Conducted on 33biocenoses and associations present fromsupralittoral to circalittoral zones, this reportfocuses on potential impacts caused by therising sea level, the rise in watertemperature, acidification and extremeevents.
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Due to its geographical position, Corsica is on the front linefacing challenges posed by climate change. It is, in fact, inone of the sectors where evolution forecasts for both rising airtemperatures and evapotranspiration, as well as declines inprecipitation and moisture in the soil, are the most pronounced(Rhone, Mediterranean and Corsica Water Agency). Theforecasts available indicate a decline i) in annual flow (10 to40 % lower by 2070) and ii) in groundwater recharge fromprecipitation, which will result in increasing scarcity of waterresources, especially in summer.
These modifications will have repercussions on the state ofthe environment and economic development, but also on thequality of living conditions. It is clear that climate changealready exerts additional pressure on the functioning of theisland's socio-ecosystem, and it is on the basis of thisobservation that the Collectivity of Corsica participates in theConference of the Peripheral Maritime Regions (CPMR),notably via the presidency of the CPMR's Commission onIslands, in which aspects of climate change are regularlyaddressed and incorporated into reflections at European level.The Collectivity of Corsica also undertakes initiatives relatedto this issue. Several programmes can thus be mentioned,already aiming to: — understand the environmental functioning of the west
Mediterranean basin under the pressure of global changein order to predict future evolution (Regional ObservationCentre for the Monitoring of the Climate and theAtmospheric and Oceanographic Environment in theWestern Mediterranean, which works to improvecharacterization and comprehension of the water cycle inthe Mediterranean bassin – HyMeX, and to compile apresent and future assessment of the chemicalatmospheric environment of the Mediterranean basin, andits regional impacts on climate, air quality, and marinebiogeochemistry – ChArMEx);
— follow the evolution of environmental conditions(measurement of seawater temperatures – TMedNet &TCorseNet);
— study the evolution of the coastline (Observation Networkof the Corsican Shoreline), gain a clearer understanding ofthe risks of marine submersion in order to develop acommon strategy and identify solutions to be acted upon(MAREGOT) or propose innovative solutions to adapt tothese inevitable changes (Adapto);
— improve understanding of the functioning of the differentcoastal marine ecosystems that exist in the Mediterraneanand describe the influence of human pressure on them(STARECAPMED);
— encourage monitoring and conservation of key ecosystems(Posidonia Monitoring Network, Padduc-Change project);
— detect as early as possible the arrival and installation ofpotentially dangerous exotic species (Corsica Alien SpeciesNetwork), define strategies (INVALIS) and limit theircirculation (ALIEM);
— incite MPA managers to reinforce their resilience andadaptation to climate change (MPA-Adapt).
In the face of present and future challenges, the territory'sresilience will depend on the introduction of governance,concerted and pooled management, but also sharedknowledge of what is in the process of happening and whatcould happen over the medium term, to allow for betterpreparation and try to provide responses adapted to the risksbeing faced.
The purpose of this Report Card is to offer Corsica's decision-makers and authorities a forward-looking tool to provideinformation on adaptation and resilience by establishing a linkbetween the best scientific information available on climatechange within its territory and priorities in adaptivemanagement. It thus presents a survey of the knowledgeavailable on the impact of climate change in marine andcoastal environments.
On the basis of this knowledge, it identifies the most likelyevolutions, which are given probability ratings. Finally, itsuggests leads aimed at supporting the development,improvement and implementation of adaptation and resiliencestrategies, together with a reflection on the strategic roleplayed by MPAs within this context.
Taking inspiration from work accomplished by the InternationalUnion for Conservation of Nature (IUCN) with support from theFrench Agency for Biodiversity (AFB), this Report Card is aMediterranean offshoot of annual Report Cards produced bythe Marine Climate Change Impacts Partnership (MCCIP). The report is the result of a joint reflection undertaken by agroup of experts concerned by climate change in Corsica,working with experts from the IUCN and its World Commissionon Protected Areas. Focusing on a particular theme, eachteam drafted a document analyzing current information.Experts then met at several workshops to draft the synthesesthat are presented here. For each one, the experts identifiedgaps in knowledge, and offered probability ratings : high forelements which are certain, medium for elements for whichdoubts persist, and low for elements which remain within therealm of hypothesis.
The MCCIPhttp://www.mccip.org.ukThe MCCIP is a partnership of scientists, government agencies and NGOs. Its goal is to develop a long-term, multi-disciplinary approach in order toprovide information on the implications of climate change in British waters.
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CONTENTSClimate change and the physical environment p. 3Climate change and the living environment p. 6Climate change and human activities p. 13Marine protected areas p. 15Conclusion p.16
The backing papers of this work are available on the website of thecoastal ecosystems team (Equipe Ecosystèmes Littoraux)https://eqel.universita.corsica
3 The average annual air temperature in Corsica hasrisen since 1970 by about 1 °C on the coast, and byover 2 °C at altitudes above 500 meters.
3 There is no clear overall trend in the evolution of annualprecipitation linked to climate change, though thefrequency of dry years since the 1990s has risen fromone year in five to one year in two.
3 There is an increase in extreme precipitation withrainfall attaining over 200 mm in 24 hours in autumn. 38extreme events were recorded from 1958 to 2017,versus 4 in the previous 120 years.
3 Evapotranspiration is the quantity of water whichevaporates through the soil, sheets of water and planttranspiration.In Corsica, its annual level is rising: previously lowerthan 1,000 mm, it has exceeded this level over the past10 years. The gap between precipitation andevapotranspiration is thus widening, accentuating thedeficit.
3 In Ajaccio, average annual rainfall has declined : 600mm per year over the past 30 years, 440 mm per yearover the past 3 years.In Bastia, average rainfall was 800 mm per year in theperiod from 1981 to 2010, whereas it is now 690 mmper year (ie. a decline of 13.5 %).
3
According to studies by the Intergovernmental Panel onClimate Change (IPCC 16), a substantial rise intemperatures is to be foreseen: around 2 °C dependingon seasons and scenarios from now until 2050, 2 to 6 °C by 2100. In all events, the rise in temperatures in theMediterranean will be higher than the rise oftemperatures worldwide.
3
The rise in temperature in mountainous regions ofCorsica will be even more substantial.In 2050, the coastal zone of Corsica will experience thecurrent climate of Tunis.
3 There is no clear trend in the evolution of extremeprecipitation based on the modelling.
3
Models show that there is an on-going trend towardsincreased dryness, especially on the west side ofCorsica, due to the change in the direction of prevailingwinds combined with modifications of the ocean-atmosphere regime of the North Atlantic (North AtlanticOscillation).
3
The coastal area will be increasingly dependent onenvironmental conditions in the mountain ranges.
GAPS IN KNOWLEDGE:More meteorological data needs to be acquired on theisland's interior.
STRATEGY :Introduce an integrated management policy betweenwatersheds and the coastal area.
Agnello Tower, Cap Corse. Photo : Christine Pergent-Martini.
A1-Température et précipitationsA. Orsini, C. Mori & P. RébilloutTEMPERATURE AND PRECIPITATION
3 Since the 80s, even though measurements show hotterperiods followed by colder periods, the averagetemperature of surface water is rising.
3
Over the past five years, the temperature of surfacewater rose by 2 °C during winter periods, and 0.5 °C insummer periods.
3
The warming of the water favours deeper thermoclines.These past five years, the depth of the thermocline hastended to drop by over 40 m.
3
The trend towards a rise in the temperature of surfacewaters (0 – 100 m) will continue, specifically in thewinter period.
3
The wind will affect the formation and disappearancedynamics of thermoclines.
3 Evolution in sea water temperature will affect marinehabitats and encourage the naturalization of exoticspecies.
SEA TEMPERATURE
STRATEGY:Share data and increase the number of measuringstations to cover Corsica's entire coastal area (networks,protocols) in order to dispose of statistically validatedtime series.
Rise in surface water temperature : anomalies observed in 2017/18 as compa-red to averages in the months of September and February, 1986-2009.
3 The overall rise in the sea level is estimated at 3 mmper year.
3 Values calculated in Ajaccio : on average 4 mm per yearbetween 2004 and 2017.
3 Le niveau de la mer élevé, allié à des événementsclimatiques (vent, pression), conduit à des phénomènesextrêmes (submersions marines et inondations).
3 Over the next 20 to 30 years, the sea level will continueto rise, though its amplitude over the longer term isdifficult to estimate.
RISING SEA LEVEL
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Climate changes being witnessed (winds : force anddirection) are already significant enough to modify thegeneral structure of the water column:— Diminished intensity of winds in winter significantly
reduces wintertime ventilation and the upwelling ofnutrients associated with it. This leads to aconsiderable reduction in phytoplanktonic bloomsand modification of the trophic succession whichdepends on it (zooplankton, larvae of crustaceans,molluscs and fish).
— The higher number of wind-related events in summerfavours mixing to such an extent that it results inperturbation of the thermocline (presence, depth).
3 There is no regular measurement of evolution in wateracidification due to CO2 emissions.
3
Any rise in the temperature of surface water in winterwill encourage further stratification of the water column,leading to reduced mixing and lower inputs of nutrients.
3
Higher wind intensity in summer which destroys, eitherpartly or fully, the stratification of water masses willmodify the oligotrophic character (low levels ofnutrients) that is naturally found in summer, andencourage the development of non-native, or eveninvasive and/or toxic planktonic species.
3
Reduced availability of nutrients in winter will restrictphytoplanktonic production and could lead tomodifications of the populations comprising this firstlevel in the food chain. Such changes in the quantityand quality of nourishment will have repercussions onall marine organisms living on the seabed and in thewater column.
3
Wind will affect thermocline dynamics (formation anddisappearance), while acidification of the water will havean impact on calcification.
CURRENTS AND WINDS
GAPS IN KNOWLEDGE:The lack of historic data on Corsica does not allow forprecise forecasts.STRATEGY:Extend and sustain the network of tide gauges aroundCorsica.Take forecasts of a rising sea level into account in coastaldevelopment (cf coastal erosion).
GAPS IN KNOWLEDGE:More knowledge is required about currents, mainly atcoastal level, and extreme events affecting the shorelinearea.STRATEGY:Optimize good management of anthropogenic inputs tolimit imbalances and cumulative effects.
A3-Courants et ventsP. Lejeune & S. Gobert
A4-Élévation du niveau de la mer JC. Romano, S. Gobert & P. Lejeune
3 Due to the cumulated effects of rising temperatures,reduced precipitation in summer and the increasingscarcity of snow in winter, the flow of stream water hasdropped by 20 to 30% since the mid 1980s.
3 During a hydrological cycle, extreme events (high andlow water levels) are more frequent and morewidespread.
3 The distribution area of Corsica's endemic aquaticspecies is becoming smaller as they move upstream inresponse to rising water temperatures.
3 The biodiversity of fresh water ecosystems isthreatened by climate change and the proliferation ofnon-native species.
3 Human health is threatened by emerging or re-emerging infectious and vector-borne diseases(malaria, chikungunya, dengue, zika, etc.) fostered byhigher temperatures.
3 The increased proliferation of toxic cyanobacteria inreservoirs constitutes a danger for users of this waterresource.
3 There is an impact on the energy sector when waterlevels in reservoirs are low, which undermines multi-annual energy programming.
3 The impact on water resources will be greater, mainlydue to rising temperatures and evapotranspiration.
3
Rising temperatures in fresh water ecosystems willresult in a higher risk of extinction of endemic species.
3
There will be a higher risk of the development ofinfectious and vector-borne diseases having an impacton human health.
3 More frequent proliferation of cyanobacteria inreservoirs will constitute additional risks for users ofwater not only for recreational activities but also fordomestic consumption (drinking water) or agriculturaluse (irrigation, watering of livestock).
3
Rarity of water resources will lead to price increaseswith economic consequences and an impact on touristactivity.
WATERSHEDS AND RIVERS
Valley of La Restonica.Photo : Antoine Orsini.
B1-Bassins versants et rivièresC. Mori & A. Orsini
Lagoon of Urbino,Photo : Bilan PDRC 2007/2013 sur les bassins versants des quatre principales lagunes de Corse OEC – janvier 2016.
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3 These systems are particularly vulnerable to climatechanges, especially with the increase in extremeweather phenomena such as torrential rain.
3
Rising water temperatures and the intensity of freshwater inputs lead to the emergence of potentially toxicspecies of phytoplankton. This reaction varies from onezone to another because of their different situations.
3 Over the past 30 years, the intensity and frequency ofproliferations of phytoplankton, including its harmfulspecies, have increased in humid coastal areas.
3 There are about a dozen toxic phytoplanktonic speciesthat are known to appear and proliferate in theseenvironments. These proliferations have repercussionson the food chain, associated fisheries and shellfishaquaculture.
3 Humid coastal areas will experience greater variationsin both frequency and intensity (temperature, waterlevels and precipitations).
3
Proliferations of phytoplankton and algae will continueand intensify, which will perturb the food chain andshellfish aquaculture, and could affect seaside activitieson the adjacent coast.
COASTAL LAGOONS
STRATEGY:Maintain, and even better, reinforce existing observationnetworks.Manage ecological continuum (marine environment andwatersheds) and improve the quality of water in liaisonwith watershed management entities.
Lagoon of Biguglia
Lagoons of Terrenzana and DianaLagoon of UrbinoLagoon of Palo
3 Coastal marine habitats which are iconic of Corsica(seagrass, coralligenous beds) are beginning to beaffected by climate change.
3 While Posidonia is regressing in many areas in theMediterranean, it is here relatively stable, even thoughthe rising sea level is causing seagrass at deep levelsto die.
3
Abnormal rises in the sea water temperature (heatstress) explain massive mortality, especially in speciescharacteristic of coralligenous populations (gorgonians,sponges).
3 The regular rise in the sea level is causing lower vitalityin the Lithophyllum pavement, but also a reduction inthe amount of light, which has an impact on deepPosidonia meadows.
3
Simplification of ecosystems and modifications of foodchains caused by climate change will have an effect onecosystem services (eg. fisheries resources, protectionagainst erosion).
3
Increasing heat anomalies will lead to more frequentphenomena of massive mortalities.
3
Acidification of the water will lead to regression ofbioconstruction formations.
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The consequences of climate change will result in thedisappearance of Corsica's main "natural landmarks"(Posidonia platform reef, Lithophyllum pavement,coralligenous atolls).
COASTAL HABITATS
GAPS IN KNOWLEDGE:Evaluation of modifications engendered by acidificationin organisms and habitats.
STRATEGY:Enable better conservation of the natural landmarks andhabitats that are most sensitive to climate change byincorporating them into efficient, representative MarineProtected Areas (cf. AMP).Ensure maintenance of ecosystem services for habitatsthat are the most sensitive to climate change(conservation, restauration).
Lithophyllum pavement, La Scandola.Photo : Gérard Pergent.
Anomalies observed in the composition and dynamicsof zooplankton result from variations in phytoplanktonrelated to climate change.
3 Wider proliferations of jellyfish are being seen in coastalwaters, though no direct connection with climate changehas yet been proven.
3 Since the 1970s, on the west coast, a decline in theproduction of phytoplankton has been regularlyrecorded and linked to climatic variations.
3
On the east coast, since 2009, changes in speciescomprising phytoplankton have been brought to light,linked to climate changes, but also human activitiesaround the lagoons.
3 As Corsica's coastal plankton ecosystem depends onnatural climate forcings (seasons), all modifications inthe climate will lead to changes in the dynamics ofcoastal water masses and thus the plankton ecosystem.
3
Persistent modifications in the climate in winter willreduce the abundance of phytoplankton, with directconsequences on all coastal ecosystems.
3
Modifications in the quality and quantity of plankton willlead to replacement of key species, with possibleecological and economic consequences (notably onfishing).
PLANKTON
GAPS IN KNOWLEDGE:Lack of knowledge about the origins of phtyplanktonproliferations in Corsica's lagoons.
Phyto- and zooplankton.Photos : G. T. Taylor, Marie Garrido.
3 Climate change is a very serious additional threat facingfish populations, already weakened by human activities(coastal development, pollution, recreational fishing,etc.).
3 Increasingly frequent observations are being made ofspecies benefiting from climate change, such aspipefish, white grouper, barracuda, Mediterraneanparrotfish.
3 Several thermophile species (eg. barracuda, peacockwrasse) now reproduce in Corsica.
3
Several species with an affinity for cold water have beenobserved less and less frequently over the past fewdecades, such as the angel shark, brown scorpionfishand cuckoo wrasse.
3
Climate change will exacerbate the decline of marinefish populations already affected by the exploitation ofliving resources and degradation of the environment.
3
Species of fish already favoured by climate change willcontinue to extend their distribution areas and theirabundance.
FISH
STRATEGY:Take the evolution of fish populations into considerationin fisheries management (cf fishing).Conduct more observation of thermophile andthermophobic species in order to follow more closely theconsequences of climate change in this compartment (cf.temperature measurement).
B5-PoissonsJM. Culioli
Above : shoal of barracudas, Lavezzi. Right page : loggerhead sea turtle, striped dolphins, and aythya diving ducks. Photos : Gérard Pergent, Artescienza, Andreas Trepte/www.photo-natur.net.
3 The ten or so species of cetaceans found in the watersaround Corsica suffer no impact from climate change.
3
The loggerhead sea turtle, the main species in Corsica,is not directly affected by climate change.
3
Modifications in the food chain linked to climate changemay have indirect consequences on the distribution ofsome cetacean species.
3
In the case of sea turtles, rising temperatures will havean impact on food resources, favour nesting and modifythe sex-ratio of newborn turtles.
3
The rising sea level will have an effect on potential egg-laying sites.
MARINE MAMMALS AND SEA TURTLES
GAPS IN KNOWLEDGE:Data is lacking on migrations and the diet of sea turtlesand cetaceans.STRATEGY:Ensure conservation of egg-laying sites and conductsurveys of sea turtles' nests.
3
Certain seabirds such as puffins return earlier andearlier in the year.
3 Wintering of pink flamingos in Corsica, as well as that ofother large waders such as herons, is encouraged bymilder winters in the Mediterranean and reducedavailability of water in North Africa.
3
The number of seabirds and aythya ducks that come tohibernate in Corsica is falling due to milder winters.
3
Cumulative effects of climate change and humanactivities will exacerbate threats faced by birds.
3
The rising sea level will lead to alteration of coastalareas and the small islands thus formed will encouragenesting among certain species of colonial birds.
BIRDS
GAPS IN KNOWLEDGE:Lack of regular observation of sea and coastal birds inCorsica.STRATEGY:Adapt opening and closing dates of the hunting season topreserve migratory and breeding birds as much aspossible.
3 Coastal vegetation plays a major role in attenuatingclimate change (carbon fixation and sequestration) ;Posidinia, the most effective species in this respect,covers over 60 % of the sea at depths between 0 and40 m in Corsica.
3 There are other habitats around the island likely to playa part in carbon fixation and sequestration (eg. maerl,coralligenous, seagrass).
3 The rising sea level will accentuate regression of deepseagrass meadowss (lower limits) due to less light onthe seabed.
3 Regression of Posidonia seagrass will reduce itscapacity for carbon sequestration as well as otherecosystem services it provides.
3
Deterioration of the Posidonia bed caused by humanactivities (anchoring, trawling) will release part of thesequestered carbon and worsen the effects of climatechange.
3
The rise in water temperature will affect the carbonfootprint of coastal vegetation and give rise to higheremissions of carbon dioxide.
SEAGRASS AND CARBON CAPTURE
STRATEGY:Preserve the carbon sink by taking appropriate measures(eg. anchorage management, reinforcement of bans ontrawling).Create Marine Protected Areas dedicated to theconservation of carbon sinks.
B8-Herbiers et capture du carboneG. Pergent, C. Pergent-Martini & B. Monnier
3 Complex natural mechanisms causing coastal erosionare affected by anthropogenic pressures (eg. dredging,sand replenishment, urban development of the coast),but also by climate change (eg. rising sea level,extreme events).
3 The average annual speed of the rise in the sea levelhas increased over the past decades.
3 The impact of climate change on coastal areas is notestablished from a statistical viewpoint, despite thepresence of habitats that are vulnerable to erosion (eg.sandy beaches, low-lying land).
3 Forecasts for rising sea levels (last IPCC report) showthat by the year 2100 the rise will be from 0.3 to 0.5 m inthe Mediterranean.
3
The rising sea level will increase coastal risks (erosionand flooding) with marked disparities at local level.
3
Increasing frequency and intensity of storms (extremeevents) will have an impact on coastal erosion.
COASTAL EROSION
STRATEGY:Shoreline management must anticipate and addressincreasing risks of marine submersions and coastalerosion.
Above : cliffs of Bonifacio.
Left page : Posidonia seagrass meadow and Pinna nobilis (noble pen shell).
Photos : Gérard Pergent.
C1-Érosion côtièreT. Pelte, A. Honorez, N. Frissant & J. Mugica
3 Climate change is encouraging the arrival of new non-native thermophile species and the naturalization of acertain number of them (eg. natives of the Red Sea orSouth Atlantic).
3 Several of these species (eg. caulerpa, ostreopsismicro-algae, comb-jelly Mnemiopsis or "Americanjellyfish") have an invasive character and poseproblems for certain socio-economic activities (eg.fishing, tourism).
3 The arrival of new species and their possiblenaturalization will continue with unforeseeableconsequences in ecological, economic and publichealth terms.
3
Naturalization of species already observed within the"Alien Corse" network (trumpet fish and rabbitfish) andthe arrival of species which already pose problems inother Mediterreanean regions (balloon fish, lionfish,stonefish) will thus have an impact on the functioning ofecosystems and economic activities, fishing inparticular.
NON-NATIVE SPECIES
STRATÉGIE :Fédérer les actions concernant le recensement et le suivides espèces non-indigènes en collaboration avecl’ensemble des acteurs.Anticiper et intégrer les modifications induites parl’arrivée des espèces non indigènes dans la gestion desactivités économiques comme la pêche ou le tourisme.
3
Certain species of commercial importance (spider crab,edible sea-urchin) are showing changes in behaviour(modification of the reproduction period).
3 Effects of climate change on species allow newresources for fisheries to be exploited (eg. whitegrouper, barracuda).
3 The future of fisheries is uncertain in the context ofeffects of climate change.
3
The arrival of new thermophile species may not onlyconstitute new fisheries resources, but also give rise toecological imbalances and economic impacts.
FISHING
GAPS IN KNOWLEDGE:Long-term data on the species exploited should be linkedto data on climate change.
STRATEGY:Take the effects of climate change on fisheriesmanagement into consideration.
Caulerpa. Photo : Gérard Pergent.
C2-Espèces non indigènesP. Francour, V. Raybaud, C. Pergent-Martini & Joseph Donini
Marine protected areasMarine Protected Areas (MPAs) are watchdogs andlaboratories. They make it possible for alerts to be raised onchanges observed in the marine environment, and tounderstand phenomena arising within it. Corsica benefits fromrecognized experience in terms of management of the marineenvironment thanks to the creation of fishing reserves in the1960s, then Corsica's Regional Nature Park in the 1970s and,since 1975, nature reserves which now cover almost 7.5% ofCorsica's territorial waters. Corsica's MPAs comprise a realwatchdog network capable of identifying the impacts ofclimate change.
Scientific data acquired over several decades in the NatureReserves of Les Bouches de Bonifacio (RNBB) and Scandolanow provide extensive and reliable data for the study ofclimate change, particularly within the Mediterranean networkof MPAs. In 2007, climate change was identified as having aninfluence on the overall functioning of the RNBB. Examples ofits impact there are numerous : erosion due to the highfrequency of exceptional storms, storms from the east givingrise to deposits of Posidonia foliage, more frequentappearance of velella, massive mortality among Gorgonians inperiods of scorching heat. Likewise, extensive mortality in redcoral has been recorded in Scandola. In all the MPAs, multiple impacts on fish have been observed:mortality of groupers caused by nodaviruses accentuated byhigh temperatures, more extensive presence of non-nativespecies, some invasive, and thermophile species in fishingnets or divers' observations.
In addition to their watchdog role, MPAs provide real sites forexperimentation to define management practices with all thesocio-economic players needing to take climate change intoaccount. They contribute to communication on climate changeissues, their understanding by decision-makers and citizens,and thus to the definition of adaptation strategies, thanks inparticular to pilot projects. MPA managers thus need to bepro-active in incorporating problems related to climate changeinto the management of their areas. Management measuresshould not only make it possible to identify anthropogenicpressures accentuated by the effects of climate change as, forexample, the prolongation of tourist seasons which heightenspressure caused by tourist activities (disturbance of avifauna,degradation of remarkable natural landmarks, anarchicanchoring which destroys coralligenous assemblages andPosidonia meadows), but also to guarantee the practical roleof MPAs in attenuating climate change (carbon sinks) andreinforcing the resilience of protected ecosystems.
They must:— limit accidents related to drought, such as fires on the
islands, and the impact of activities involving impairment ofthreatened species or habitats;
— encourage good practices by making information availableto the general public, promoting new species on the localmarket, enabling adaptation on the part of small coastalfisheries, and speeding up management activities fornautical tourism;
— communicate on the role of the reserve effect whichimproves the ability of ecosystems to adapt to changeswithout provoking major alterations.
In conclusion, preservation of the capital of Corsica's coastaland marine biodiversity is seen as an example in theMediterranean basin, though climate change now threatensthese progressive policies associating the protection of marinebiodiversity with sustainable development of the shoreline andthe sea. Even with their long experience of management,Corsica's marine protected areas will have to adapt to allowfor optimal conservation of this biodiversity. To this end, theydispose of series of long-term scientific data, awardedcredibility through scientific consultation, which can serve as abase for planned management action, attenuating the effectsof climate change and encouraging adaptation on the part ofMPA managers and users. Today, scientific activity must befirmly focused on understanding phenomena linked to climatechange, and must offer simple, coordinated scientific follow-upwithin MPAs placing all the scientific data and theirmanagement experience at the disposal and service ofambitious, global projets for the Mediterranean.
While the coast is currently a driver behind economicdevelopment in Corsica, it seems to be particularlyvulnerable to modifications induced, directly or indirectly,by climate change. Its ability to respond to the pressuresbeing applied, especially in terms of water resources, willlargely depend on the smooth functioning of itswatersheds. The marine environment will also beparticularly affected, whether in terms of the quality ofsea water or conservation of ecosystems and the speciesthey accommodate. Taking probable and foreseeableconsequences of climate change into account indevelopment strategies for Corsica's coastal areas(erosion, submersion, management of living resources,tourism) thus seems indispensable.
In this context, any approach to land developmentprojects, for which coastal and marine protected areasare privileged tools, should be based on a shared,dynamic and functional vision of natural and culturalheritage. Consideration of upsteam-downstreamrelationships and the complementary nature of differentareas (mountain/shoreline/sea), as well as their "commondestiny", is a guarantee of success in the process ofadapting to consequences of climate disturbance, makingus reflect on taking climate change into account in termsof ecological solidarity.
ConclusionThis study was undertaken by Dan Laffoley, John Baxter,Christine Pergent-Martini, Gérard Pergent, Maria del MarOtero and François Simard, with the participation of:
