Suchergebnisse

The French government has set a target of 23% of energetic consumption derived from renewable energy sources including Marine Renewable Energy for 2020. Eight offshore wind farms (OWF) are planned along the Atlantic-English Channel French coasts and among them Dieppe-Le Tréport site in the eastern part of the English Channel. In order to gain further knowledge on the ecosystem structure and functioning before the OWF installation, my PhD thesis is focused on the construction of an Ecopath Model on the wind farm site in comparison with similar benthic habitats from the English Channel. The collection of new data on biological compartments (zooplankton, suprabenthos, meiofauna, benthos and demersal fishes) are essential. Four cruises (summers 2014 /2015 and winters 2015 /2016) allowed toestimate the contribution of each zoological group in two main benthic habitats: i.e. sandy gravels and medium clean sands, founded on the site (about 30 km²), corresponding to two microbenthic communities well represented in the English Channel. Macrofauna was sampled with a Van Veen grab,suprabenthos with a modified Macer-Giroq sledge in one station from each benthic habitat (day and night sampling) and fish with a beam trawl in ten stations. A total of 1,584 demersal fishes has been collected and their stomach contents has been examined. The results show the importance of large bivalves in the benthic biomass whereas the crustaceans are preferential preys of fishes. This link is discussed within the trophic network between consumed and non-consumed species of benthic communities, and the concept trophic 'cul de sac'. ; Le gouvernement français a fixé pour objectif que 23% de la consommation énergétique proviendrait des énergies renouvelables, y compris les énergies renouvelables marines pour 2020. Huit parcs éoliens en mer sont prévus le long des côtes françaises Atlantique-Manche, parmi lesquels le site de Dieppe-LeTréport dans la partie orientale de la Manche. Afin de mieux connaître la structure et le fonctionnement de cet ...

The French government has set a target of 23% of energetic consumption derived from renewable energy sources including Marine Renewable Energy for 2020. Eight offshore wind farms (OWF) are planned along the Atlantic-English Channel French coasts and among them Dieppe-Le Tréport site in the eastern part of the English Channel. In order to gain further knowledge on the ecosystem structure and functioning before the OWF installation, my PhD thesis is focused on the construction of an Ecopath Model on the wind farm site in comparison with similar benthic habitats from the English Channel. The collection of new data on biological compartments (zooplankton, suprabenthos, meiofauna, benthos and demersal fishes) are essential. Four cruises (summers 2014 /2015 and winters 2015 /2016) allowed toestimate the contribution of each zoological group in two main benthic habitats: i.e. sandy gravels and medium clean sands, founded on the site (about 30 km²), corresponding to two microbenthic communities well represented in the English Channel. Macrofauna was sampled with a Van Veen grab,suprabenthos with a modified Macer-Giroq sledge in one station from each benthic habitat (day and night sampling) and fish with a beam trawl in ten stations. A total of 1,584 demersal fishes has been collected and their stomach contents has been examined. The results show the importance of large bivalves in the benthic biomass whereas the crustaceans are preferential preys of fishes. This link is discussed within the trophic network between consumed and non-consumed species of benthic communities, and the concept trophic 'cul de sac'. ; Le gouvernement français a fixé pour objectif que 23% de la consommation énergétique proviendrait des énergies renouvelables, y compris les énergies renouvelables marines pour 2020. Huit parcs éoliens en mer sont prévus le long des côtes françaises Atlantique-Manche, parmi lesquels le site de Dieppe-LeTréport dans la partie orientale de la Manche. Afin de mieux connaître la structure et le fonctionnement de cet écosystème avant l'installation du parc éolien, ma thèse est axée sur la construction de modèles de réseau trophique à l'aide du logiciel Ecopath sur ce site d'implantation en comparaison avec des habitats benthiques similaires en Manche. La collecte de nouvelles données sur les compartiments biologiques (zooplancton, suprabenthos, méiofaune, benthos et poissons démersaux) est essentielle.Ainsi, quatre campagnes (étés 2014/2015, hivers 2015/2016) ont permis d'estimer la contribution de chaque groupe zoologique dans deux habitats benthiques principaux : les graviers ensablés/sables graveleux et les sables moyens sur le site (environ 30 km²) correspondant à deux communautés benthiques largement répandues en Manche. La macrofaune a été échantillonnée avec une benne Van Veen, le suprabenthos avec un traîneau Macer-Giroq modifié avec une station dans chaque habitat benthique (échantillonnage jour et nuit) et les poissons avec un chalut à perche. Au total, 1 584 poissons démersaux ont été recueillis et leurs contenus stomacaux ont été examinés. Les résultats montrent que le site se distingue par la forte contribution des bivalves en termes de biomasses et que les crustacés sont des proies préférentielles des poissons. Ce lien est discuté à travers l'analyse du réseau trophique avec un focus sur les espèces consommées et non consommées de communautés benthiques, et la notion de cul de sac trophique.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; Since the beginning of the 2000', the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

International audience ; As part of the energy transition, the French government is planning Offshore Wind Farm (OWF) constructions in the next decades. An integrated ecosystem approach of two future OWF sites of the Eastern English Channel (Courseulles-sur-mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before the OWF implementation. Such ecosystem models allow simulating the possible reef and reserve effects associated to the presence of the farm, and to character the overall changes in the food-web functioning. This holistic view of OWF effects could be replicated on other sites and form the basis of an ecosystem based management of marine renewable energies. However, to use these models for management purpose, they need to be validated. In order to do so, stable isotope ratios of nitrogen were used for determining the accuracy of the effective trophic levels computed in these two models. Results showed that trophic levels estimated by the two models were consistent with the trophic levels estimated by the independent isotopic data. In the context of OWF development and cumulative impacts analysis, this step of validation of the models is essential for developing their use by management actors and policy makers. © 2020 Elsevier Ltd

International audience ; As part of the energy transition, the French government is planning Offshore Wind Farm (OWF) constructions in the next decades. An integrated ecosystem approach of two future OWF sites of the Eastern English Channel (Courseulles-sur-mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before the OWF implementation. Such ecosystem models allow simulating the possible reef and reserve effects associated to the presence of the farm, and to character the overall changes in the food-web functioning. This holistic view of OWF effects could be replicated on other sites and form the basis of an ecosystem based management of marine renewable energies. However, to use these models for management purpose, they need to be validated. In order to do so, stable isotope ratios of nitrogen were used for determining the accuracy of the effective trophic levels computed in these two models. Results showed that trophic levels estimated by the two models were consistent with the trophic levels estimated by the independent isotopic data. In the context of OWF development and cumulative impacts analysis, this step of validation of the models is essential for developing their use by management actors and policy makers. © 2020 Elsevier Ltd

International audience ; As part of the energy transition, the French government is planning Offshore Wind Farm (OWF) constructions in the next decades. An integrated ecosystem approach of two future OWF sites of the Eastern English Channel (Courseulles-sur-mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before the OWF implementation. Such ecosystem models allow simulating the possible reef and reserve effects associated to the presence of the farm, and to character the overall changes in the food-web functioning. This holistic view of OWF effects could be replicated on other sites and form the basis of an ecosystem based management of marine renewable energies. However, to use these models for management purpose, they need to be validated. In order to do so, stable isotope ratios of nitrogen were used for determining the accuracy of the effective trophic levels computed in these two models. Results showed that trophic levels estimated by the two models were consistent with the trophic levels estimated by the independent isotopic data. In the context of OWF development and cumulative impacts analysis, this step of validation of the models is essential for developing their use by management actors and policy makers. © 2020 Elsevier Ltd

International audience ; As part of the energy transition, the French government is planning Offshore Wind Farm (OWF) constructions in the next decades. An integrated ecosystem approach of two future OWF sites of the Eastern English Channel (Courseulles-sur-mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before the OWF implementation. Such ecosystem models allow simulating the possible reef and reserve effects associated to the presence of the farm, and to character the overall changes in the food-web functioning. This holistic view of OWF effects could be replicated on other sites and form the basis of an ecosystem based management of marine renewable energies. However, to use these models for management purpose, they need to be validated. In order to do so, stable isotope ratios of nitrogen were used for determining the accuracy of the effective trophic levels computed in these two models. Results showed that trophic levels estimated by the two models were consistent with the trophic levels estimated by the independent isotopic data. In the context of OWF development and cumulative impacts analysis, this step of validation of the models is essential for developing their use by management actors and policy makers. © 2020 Elsevier Ltd

International audience ; As part of the energy transition, the French government is planning Offshore Wind Farm (OWF) constructions in the next decades. An integrated ecosystem approach of two future OWF sites of the Eastern English Channel (Courseulles-sur-mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before the OWF implementation. Such ecosystem models allow simulating the possible reef and reserve effects associated to the presence of the farm, and to character the overall changes in the food-web functioning. This holistic view of OWF effects could be replicated on other sites and form the basis of an ecosystem based management of marine renewable energies. However, to use these models for management purpose, they need to be validated. In order to do so, stable isotope ratios of nitrogen were used for determining the accuracy of the effective trophic levels computed in these two models. Results showed that trophic levels estimated by the two models were consistent with the trophic levels estimated by the independent isotopic data. In the context of OWF development and cumulative impacts analysis, this step of validation of the models is essential for developing their use by management actors and policy makers. © 2020 Elsevier Ltd