References of "Champenois, Willy"
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See detailMassive marine methane emissions from near-shore shallow coastal areas
Borges, Alberto ULg; Champenois, Willy ULg; Gypens, N et al

in Scientific Reports (2016), 6

Methane is the second most important greenhouse gas contributing to climate warming. The open ocean is a minor source of methane to the atmosphere. We report intense methane emissions from the near-shore ... [more ▼]

Methane is the second most important greenhouse gas contributing to climate warming. The open ocean is a minor source of methane to the atmosphere. We report intense methane emissions from the near-shore southern region of the North Sea characterized by the presence of extensive areas with gassy sediments. The average flux intensities (~130 μmol m−2 d−1) are one order of magnitude higher than values characteristic of continental shelves (~30 μmol m−2 d−1) and three orders of magnitude higher than values characteristic of the open ocean (~0.4 μmol m−2 d−1). The high methane concentrations (up to 1,128 nmol L−1) that sustain these fluxes are related to the shallow and well-mixed water column that allows an efficient transfer of methane from the seafloor to surface waters. This differs from deeper and stratified seep areas where there is a large decrease of methane between bottom and surface by microbial oxidation or physical transport. Shallow well-mixed continental shelves represent about 33% of the total continental shelf area, so that marine coastal methane emissions are probably under-estimated. Near-shore and shallow seep areas are hot spots of methane emission, and our data also suggest that emissions could increase in response to warming of surface waters. [less ▲]

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See detailAnnual dynamics of pCO2 within bulk sea ice and related CO2 fluxes at Cape Evans (Antarctica)
Van Der Linden, Fanny ULg; Champenois, Willy ULg; Heinesch, Bernard ULg et al

Poster (2016, February 26)

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice ... [more ▼]

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice-Atmosphere Exchanges), annual dynamics of sea ice pCO2 was compared with CO2 fluxes measured by automated accumulation chambers at Cape Evans (Ross Island, Antarctica). Results confirmed a general trend of brine pCO2 supersaturation with respect to the atmosphere during the late winter (concentration of dissolved inorganic carbon - DIC - in brine and brine expulsion in the brine skim) leading to CO2 degassing, and undersaturation during the spring (carbon-uptake by autotrophs and brine dilution) leading to atmospheric CO2 uptake. Despite high primary production at the bottom of the ice in spring, DIC profiles suggest that sea ice as a whole appears to be net heterotrophic. Still, sea ice absorbs CO2 from the atmosphere, as a result of physical processes. Some variability in the CO2 fluxes (both in magnitude and sign) could not be explained by variability in sea ice pCO2 but rather seemed driven by variability in atmospheric conditions and sea ice surface properties. For instance, in late spring, CO2 fluxes showed a diurnal variability (from CO2 degassing to uptake) related to atmospheric temperature variations. Large and episodic CO2 fluxes were systematically positively correlated with strong wind events, and large CO2 degassing was observed over thin, wet and salty snow cover. [less ▲]

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See detailAnnual dynamics of pCO2 within bulk sea ice and related CO2 fluxes at Cape Evans (Antarctica)
Van Der Linden, Fanny ULg; Champenois, Willy ULg; Heinesch, Bernard ULg et al

Poster (2016, February 12)

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice ... [more ▼]

Sea ice is a biome actively participating in the regional cycling of CO2 as both a source and a sink at different times of the year. In the frame of the YROSIAE project (Year-Round Ocean-Sea-Ice-Atmosphere Exchanges), annual dynamics of sea ice pCO2 was compared with CO2 fluxes measured by automated accumulation chambers at Cape Evans (Ross Island, Antarctica). Results confirmed a general trend of brine pCO2 supersaturation with respect to the atmosphere during the late winter (concentration of dissolved inorganic carbon - DIC - in brine and brine expulsion in the brine skim) leading to CO2 degassing, and undersaturation during the spring (carbon-uptake by autotrophs and brine dilution) leading to atmospheric CO2 uptake. Despite high primary production at the bottom of the ice in spring, DIC profiles suggest that sea ice as a whole appears to be net heterotrophic. Still, sea ice absorbs CO2 from the atmosphere, as a result of physical processes. Some variability in the CO2 fluxes (both in magnitude and sign) could not be explained by variability in sea ice pCO2 but rather seemed driven by variability in atmospheric conditions and sea ice surface properties. For instance, in late spring, CO2 fluxes showed a diurnal variability (from CO2 degassing to uptake) related to atmospheric temperature variations. Large and episodic CO2 fluxes were systematically positively correlated with strong wind events, and large CO2 degassing was observed over thin, wet and salty snow cover. [less ▲]

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See detailFirst mesocosm experiments to study the impacts of ocean acidification on plankton communities in the NW Mediterranean Sea (MedSeA project)
Gazeau, F; Sallon, A; Maugendre, L et al

in Estuarine Coastal & Shelf Science (2016)

There is a growing international interest in studying the effects of ocean acidification on plankton communities that play a major role in the global carbon cycle and in the consumption of atmospheric CO2 ... [more ▼]

There is a growing international interest in studying the effects of ocean acidification on plankton communities that play a major role in the global carbon cycle and in the consumption of atmospheric CO2 via the so-called biological pump. Recently, several mesocosm experiments reported on the effect of ocean acidification on marine plankton communities, although the majority were performed in eutro- phic conditions or following nutrient addition. The objective of the present study was to perform two mesocosm experiments in the oligo- to meso-trophic Northwestern Mediterranean Sea during two seasons with contrasting environmental conditions: in summer 2012 in the Bay of Calvi (Corsica, France) and in winter 2013 in the Bay of Villefranche (France). This paper describes the objectives of these ex- periments, the study sites, the experimental set-up and the environmental and experimental conditions during the two experiments. The 20-day experiment in the Bay of Calvi was undoubtedly representative of summer conditions in the Northwestern Mediterranean Sea with low nutrient and chlorophyll a concentrations, warm waters and high surface solar irradiance. In contrast, the winter experiment, which was reduced to 12 days because of bad weather conditions, failed to reproduce the mesotrophic con- ditions typical of the wintertime in this area. Indeed, a rapid increase in phytoplankton biomass during the acidification phase led to a strong decrease in nitrate concentrations and an unrealistic N and P co- limitation at this period of the year. An overview of the 11 other papers related to this study and pub- lished in this special issue is provided. [less ▲]

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See detailSTAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts: The STARECAPMED project
Richir, Jonathan ULg; Abadie, Arnaud ULg; Binard, Marc ULg et al

Conference (2015, November 08)

The Marine and Oceanographic Research Station STARESO in the Calvi Bay, Corsica (France), is a unique tool in a preserved natural site that includes all the characteristic ecosystems of the Mediterranean ... [more ▼]

The Marine and Oceanographic Research Station STARESO in the Calvi Bay, Corsica (France), is a unique tool in a preserved natural site that includes all the characteristic ecosystems of the Mediterranean littoral. The station, established in 1970, has archived environmental data for decades. The STARECAPMED project, multidisciplinary, articulates itself around these two main features. Its objective is to understand how human activities can interact with the fundamental processes that govern the functioning of the different coastal ecosystems of a Mediterranean bay. The understanding of these interactions involves: (i) the identification of the anthropogenic pressures; (ii) the quantification of their impacts on the ecosystems; (iii) the prioritization of these impacts. STARECAPMED also aims to confirm the relevance of the use of the Calvi Bay as a reference in the study of local and global pressures and the changes they may cause on the structure and the functioning of Mediterranean coastal ecosytems. [less ▲]

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See detailYear Round Survey of Ocean-Sea Ice-Air Exchanges – the YROSIAE survey
Delille, Bruno ULg; Van Der Linden, Fanny ULg; Fripiat, François et al

Poster (2015, September 08)

YROSIAE survey aimed to carry out a year-round integrated survey of land-fast sea ice focusing on the study of sea ice physics and biogeochemistry in order to a) better understand and budget exchanges of ... [more ▼]

YROSIAE survey aimed to carry out a year-round integrated survey of land-fast sea ice focusing on the study of sea ice physics and biogeochemistry in order to a) better understand and budget exchanges of energy and matter across the ocean-sea ice-atmosphere interfaces during sea ice growth and decay and b) quantify their potential impact on fluxes of climate gases (CO2, DMS, CH4, N2O) to the atmosphere and on carbon and macro- nutrients and micro-nutrients export to the ocean. We will present the aims, overall approach and integrated sampling strategy of the YROSIAE survey. We will also discuss CO2 and N2O dynamics within sea ice. It appears that sea ice acts as a source of CO2 for the atmosphere in winter, counterbalancing spring sink. In addition, mineralization in spring appears to alleviate spring CO2 uptake. Intense nitrification in sea ice in spring fosters emission of N2O at the air-ice interface. [less ▲]

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See detailSTARECAPMED (STAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts) - Année 2014. Rapport de recherches.
Richir, Jonathan ULg; Abadie, Arnaud ULg; Binard, Marc ULg et al

Report (2015)

La prise de conscience, par le grand public, de l'impact grandissant de l'homme sur l'océan est récente. Elle se traduit par une volonté politique sincère de correction par des mesures de protection, de ... [more ▼]

La prise de conscience, par le grand public, de l'impact grandissant de l'homme sur l'océan est récente. Elle se traduit par une volonté politique sincère de correction par des mesures de protection, de gestion et de développement durable. Ces politiques, et leurs conséquences économiques et sociétales lourdes, ne peuvent être acceptées que si les décisions se fondent sur des connaissances scientifiques incontestables et montrent des résultats scientifiquement prouvés. Par ailleurs, ces décisions doivent prendre en compte des impacts qui s'opèrent à des échelles de temps et d’espace très variables, de quelques heures à plusieurs dizaines d’années et de quelques mètres à plusieurs milliers de km. En termes politiques, l'information scientifique nécessaire à la prise de décision doit pouvoir couvrir les différentes échelles depuis le niveau local et régional, jusqu'à l'échelle nationale, européenne voire globale, et cela sur le plus long terme possible. Enfin, pour être complète, l'information scientifique sur les écosystèmes marins doit pouvoir répondre à trois questions objectives : (i) quel est l'état? (ii) quelle est l'évolution? (iii) quels sont les mécanismes et processus mis en jeux? et à une question plus prospective : (vi) que peux-t-on prévoir et comment agir? Le présent rapport ne peut pas, à lui seul, refléter toute la richesse du programme STARECAPMED. En 3 ans, STARECAPMED a généré plusieurs centaines de milliers de données nouvelles, ré-exploité plusieurs centaines de publications, rapports et autres enregistrements passés et présents. Le programme a aussi généré de nombreux documents, rapports et mémoires. Enfin, des publications internationales et des thèses de doctorat sont en cours de réalisation ou abouties. Afin de rester lisible, nous avons donc choisi de présenter ce rapport 2014 sous la forme de 12 exemples parmi les travaux en cours. Ces exemples sont traités selon un schéma identique en 4 points simples : (i) La présentation du cas d’étude dans le projet global ; (ii),Les approches innovatrices développées ; (iii),La présentation de résultats marquants ; (iv),Les délivrables de STARECAPMED pour les politiques publiques. [less ▲]

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See detailAcoustic monitoring of O2 production of a seagrass meadow
Felisberto, Paulo; Jesus, Sérgio M.; Zabel, Friedrich et al

in Journal of Experimental Marine Biology and Ecology (2015), 464(0), 75-87

Acoustic data were acquired in October 2011 over a Posidonia oceanica meadow in the Bay of la Revellata, Calvi, Corsica. The purpose was to develop an acoustic system for monitoring the oxygen (O2 ... [more ▼]

Acoustic data were acquired in October 2011 over a Posidonia oceanica meadow in the Bay of la Revellata, Calvi, Corsica. The purpose was to develop an acoustic system for monitoring the oxygen (O2) production of an entire seagrass meadow. In a shallow water area (b38 m), densely covered by P. oceanica, a sound source transmitted signals in 3 different bands (400–800 Hz, 1.5–3.5 kHz and 6.5–8.5 kHz) toward three self-recording hydrophones at a distance of 100 m, over the period of oneweek. The data showa high correlation between the diel cycle of the acoustic signals' energy received by the hydrophones and the temporal changes in water column O2 concentration as measured by optodes. The results thus show that a simple acoustic acquisition system can be used to monitor the O2-based productivity of a seagrass meadow at the ecosystem level with high temporal resolution. The finding of a significant production of O2 as bubbles in seagrass ecosystems suggests that net primary production is underestimated by methods that rely on the mass balance of dissolved O2 measurements. [less ▲]

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See detailHow snow affects air-sea ice CO2 fluxes
Delille, Bruno ULg; Kotovitch, Marie ULg; Van Der Linden, Fanny ULg et al

Poster (2014, October)

Sea ice is a significant contributor to the sink of atmospheric CO2 by polar oceans. Physical and biogeochemical sea ice processes affect partial pressure of CO2 within sea ice, that in turn controls the ... [more ▼]

Sea ice is a significant contributor to the sink of atmospheric CO2 by polar oceans. Physical and biogeochemical sea ice processes affect partial pressure of CO2 within sea ice, that in turn controls the way and magnitude of air-sea ice CO2 fluxes. Snow cover appears to affect the magnitude of the fluxes. In order to understand the role of snow, we compared chamber and micrometeorological measurements of air-ice CO2 fluxes over snow covered and uncovered sea ice (land fast and pack ice) in both arctic and antarctic. We observed significant differences between fluxes over uncovered and covered sea ice. In addition chamber and micrometeorological measurement show different patterns that are partially due to snow cover. By gathering these observations, we observed at least three effects of snow on air-ice CO2 fluxes. Snow appears to (i) act as transient CO2 reservoir (ii) affect thermal properties of the ice surface (iii) control gas transfer depending on snow structure (superimposed ice, slush). [less ▲]

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See detailCorrelation between the acoustic noise field measured in a Posidonia oceanica bed and the photosynthetic activity
Felisberto, P; Zabel, F; Rodriguez, O et al

Poster (2014, May 05)

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See detailUsing active and passive acoustics to assess O2 production of a Posidonia oceanica meadow
Felisberto, P; Zabel, F; Rodriguez, O et al

Poster (2014, March 04)

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See detailYear Round survey of Ocean-Sea Ice-Air Exchanges – the YROSIAE survey
Delille, Bruno ULg; Haskell, T.; Champenois, Willy ULg et al

Conference (2014, March)

YROSIAE survey aimed to carry out a year-round survey of land-fast sea ice focusing on the study of sea ice physics and biogeochemistry in order to a) better understand and budget exchanges of energy and ... [more ▼]

YROSIAE survey aimed to carry out a year-round survey of land-fast sea ice focusing on the study of sea ice physics and biogeochemistry in order to a) better understand and budget exchanges of energy and matter across the ocean-sea ice-atmosphere interfaces during sea ice growth and decay and b) quantify their potential impact on fluxes of climate gases (CO2, DMS, CH4, N2O) to the atmosphere and on carbon and macro- nutrients and micro-nutrients export to the ocean. Ice cores, sea water, brines and exported material were collected at regular intervals about 1 km off cape Evans from November 2011 to December 2011 and from September 2012 to December 2012 in trace-metal clean conditions. Samples are processed to characterize both the vertical distribution and temporal changes of climate gases (CO2, DMS, CH4, N2O), CO2-related parameters (dissolved inorganic carbon, total alkalinity and CaCO3 amount), physical parameters (salinity, temperature, texture, 18O), biogeochemical parameters (macro-nutrients, particulate and dissolved organic carbon, δ13C, δ30Si and δ15N, micro-nutrients - including iron) and biological parameters ( chlorophyll a, primary production within sea ice derived from O2:Ar and O2:N ratios, autotrophic species determination, bacterial cell counts a.s.o.). In addition, we deployed a micro-meterological tower and automatic chambers to measure air-ice CO2 fluxes. Continuous measurements of ice temperature and ice accretion or melting, both at the ice-ocean and the ice-atmosphere interfaces were provided by an “Ice-T” ice mass balance buoy. Sediment traps collected particles below the ice between 10 and 70 m, while dust collectors provided a record of a full suite of trace metal and dust at different levels above the ground. We will present the aims, overall approach and sampling strategy of the YROSIAE survey. In addition we will also discuss CO2 dynamics within the ice and present temporal air-ice CO2 fluxes over the year. We will provide a first budget of air-ice CO2 fluxes during ice growth for Antarctica sea ice and discuss the impact of the snow cover on air-ice CO2 fluxes. [less ▲]

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See detailLand-fast sea ice of McMurdo Sound as a source of bio-essential trace metals for primary productivity in the Ross Sea, Antarctica
Schoemann, V.; de Jong, J.T.M.; Tison, J.L. et al

Conference (2014, March)

Iron (Fe) is an essential micronutrient. Its low abundance limits primary productivity in more than 30% of the oceans, including the Southern Ocean, and has a crucial impact on the biogeochemical cycles ... [more ▼]

Iron (Fe) is an essential micronutrient. Its low abundance limits primary productivity in more than 30% of the oceans, including the Southern Ocean, and has a crucial impact on the biogeochemical cycles of carbon and other elements with ultimate influence on the Earth climate system. Other trace metals, like Mn, Zn, Co and Cu are also required for microorganisms cell metabolism and may be (co-) limiting. Previous data on dissolved and particulate Fe concentration data showed that Fe is 10-100 times more concentrated in the sea ice than in underlying seawater and that sea ice melt can deliver up to 70% of the daily Fe supply to the surface waters. According to budget estimates in East Antarctica and in the Weddell Sea, accumulated Fe would largely derive from the underlying seawater rather than from atmospheric inputs. Most of the available data of trace metals in the sea ice concern pack ice and Fe. Only very scarce data exist on land-fast ice and on other trace metal concentrations. In this presentation, the general objective is to assess the role of land-fast ice as a source of Fe and other bio-essential trace metals (e.g. Mn, Zn, Cu, Mo, Cd), its impact on primary productivity and on the biological pump. Samples of sea ice, brines and seawater as well as dusts samples have been collected during the land-based sampling program YROSIAE at Cape Evans (Scott Base, McMurdo Sound, Ross Sea, Antarctica) from Nov 2011 to Dec 2011 and from Aug 2012 to Dec 2012. Dissolved and particulate trace metals concentrations have been measured by a recently developed method, which combines multiple element isotope dilution with preconcentration using the Nobias Chelate PA1 resin and ICP-MS analysis. Concentrations of trace metals in snow collected during the present study are one to up to five orders of magnitude higher than the concentrations previously observed in snow from East Antarctica, showing a much stronger dust input of these metals in McMurdo Sound. When comparing the concentrations obtained in the under-ice seawater with those obtained in the snow at McMurdo Sound, concentrations of Fe, Al, Mn, Co are much lower, whereas concentrations of Cu, Zn and Pb are similar and the concentrations of Ni, Mo and Cd are higher. Inventories of these trace metals in the land-fast sea ice give insights on its role as a source of bio-essential trace metal for the fuelling of the seasonal Ross Sea bloom. Other sources of these trace metals will be addressed and compared. [less ▲]

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See detailSeagrass production: linking individual, community and ecosystem carbon fluxes
Santos, R; Silva, J; Olivé, I et al

Conference (2013)

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See detailEstablishing research strategies, methodologies and technologies to link genomics and proteomics to seagrass productivity, community metabolism, and ecosystem carbon fluxes
Mazzuca, Silvia; Bjork, M; Beer, S et al

in Frontiers in Plant Science (2013), 4(38), 1-19

A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research.This enables the prediction of change and possibly the ... [more ▼]

A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research.This enables the prediction of change and possibly the mitigation of the consequences of anthropogenic impacts. One major aim of the European Cooperation in Science and Technology (COST) Action ES0609 “Seagrasses productivity. From genes to ecosystem management,” is the calibration and synthesis of various methods and the development of innovative techniques and protocols for studying seagrass ecosystems. During 10 days, 20 researchers representing a range of disciplines (molecular biology, physiology, botany, ecology, oceanography, and underwa- ter acoustics) gathered at The Station de Recherches Sous-marines et Océanographiques (STARESO, Corsica) to study together the nearby Posidonia oceanica meadow. STARESO is located in an oligotrophic area classified as “pristine site” where environmental distur- bances caused by anthropogenic pressure are exceptionally low. The healthy P. oceanica meadow, which grows in front of the research station, colonizes the sea bottom from the surface to 37 m depth. During the study, genomic and proteomic approaches were integrated with ecophysiological and physical approaches with the aim of understanding changes in seagrass productivity and metabolism at different depths and along daily cycles. In this paper we report details on the approaches utilized and we forecast the potential of the data that will come from this synergistic approach not only for P. oceanica but for seagrasses in general. [less ▲]

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See detailStare-Capmed : Présentation générale du projet et exemple d'une action : "Impact de l'ancrage sur la dynamique des herbiers de posidonies".
Michel, Loïc ULg; Champenois, Willy ULg; Borges, Alberto ULg et al

Conference (2012, May 16)

STARE-CAPMED (STAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts) est un projet de recherche mis en place par Stareso S.A.S. depuis ... [more ▼]

STARE-CAPMED (STAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts) est un projet de recherche mis en place par Stareso S.A.S. depuis janvier 2012. Il a pour objectif d’établir un site de référence à long terme pour la compréhension, par la recherche fondamentale, des processus de l’évolution des écosystèmes méditerranéens côtiers et océaniques en réponse aux changements actuels globaux et locaux des pressions anthropiques. Centré sur la Baie de Calvi et le proche large, il vise à fournir un référentiel basé sur des mesures à haute fréquence qui doivent pouvoir complémenter les réseaux de surveillance basse fréquence et de recherches existants et ainsi faire progresser la compréhension des processus. En outre, le projet doit fournir aux utilisateurs finaux (collectivités locales et régionales, administrations nationales, ...) des orientations de gestion basées sur l’analyse étayée des processus en jeux. Financé par l’Agence de l’eau RMC et la Collectivité Territoriale de Corse, le projet, multidisciplinaire, se décline actuellement selon 10 axes de travail : • Suivi du cadre hydrographique et physico-chimique • Suivi et quantification des pressions anthropiques • Ecosystème planctonique • Benthos de substrat meuble • Benthos de substrat dur et faune vagile • Phanérogames marines et écosystèmes associés • Mouillages et processus d’altération des herbiers de posidonies • Ecotoxicologie et polluants émergents • Bilan CO2 et métabolisme des écosystèmes • Zones protégées, espèces nouvelles, recrutement Pour chacun de ces axes, la stratégie d’échantillonnage est basée sur la comparaison de données obtenues durant des périodes où l’impact anthropique est faible (octobre-avril) avec celles obtenues durant des périodes de pression intense (mai-septembre), et sur la comparaison de données issues de sites de référence peu impactés avec celles provenant de sites où l’impact anthropique est reconnu. A titre d’exemple, le but de l’action "Mouillages et processus d’altération des herbiers de posidonies" est de mettre en évidence les conséquences des altérations liées à l’arrachage de faisceaux de posidonies sur la vitalité de l’herbier. Des zones où la pression de mouillage est reconnue seront définies sur base des travaux de cartographie de l’herbier, également réalisés dans le cadre du projet STARE-CAPMED. Elles seront comparées avec des zones d’herbiers sains témoins par la caractérisation du sédiment (mesures de compacité in situ, mesures des concentrations en O2 et nutriments et du pH de l’eau interstitielle, granulométrie et teneur en matière organique du sédiment, proportions de rhizomes et morts) ainsi que par la définition de l’état physiologique des faisceaux de posidonies (mesures biométriques classiques, analyses des contenus élémentaires en carbone, azote et phosphore) et par l’application d’indices écologiques définis par la DCE (PREI, BIPO, …). Les résultats obtenus permettront d’avoir une vue d’ensemble des processus par lesquels l’impact physique des mouillages de bateaux de plaisance occasionne des dégâts aux herbiers de posidonies. Ils pourront ainsi fournir une base de connaissances solide aux gestionnaires soucieux de limiter cet impact. [less ▲]

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