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Vanina Pasqualini - One of the best experts on this subject based on the ideXlab platform.
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Sea urchin–seagrasses interactions: trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m^−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
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sea urchin seagrasses interactions trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
Catherine Fernandez - One of the best experts on this subject based on the ideXlab platform.
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Sea urchin–seagrasses interactions: trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m^−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
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sea urchin seagrasses interactions trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
Gérard Pergent - One of the best experts on this subject based on the ideXlab platform.
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Sea urchin–seagrasses interactions: trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m^−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
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sea urchin seagrasses interactions trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
Lila Ferrat - One of the best experts on this subject based on the ideXlab platform.
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Sea urchin–seagrasses interactions: trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m^−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
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sea urchin seagrasses interactions trophic links in a Benthic Ecosystem from a coastal lagoon
Hydrobiologia, 2012Co-Authors: Catherine Fernandez, Lila Ferrat, Gérard Pergent, Vanina PasqualiniAbstract:Seagrasses could constitute a major component of lagunal Ecosystems. Generally, in seagrass beds, consumer control is strong. In coastal lagoons, where seagrass beds are particularly extensive, there is only scarce data on seagrass herbivory. In Mediterranean coastal lagoons, Paracentrotus lividus populations are extensive and consume Cymodocea nodosa beds. In this study, we monitored a P. lividus population during 18 months in order to analyse changes in population density and structure. On the basis of results of previous studies (i.e. biomass, density, production and nutrition parameters), we assessed the importance of P. lividus with respect to C. nodosa herbivory in a Mediterranean coastal lagoon. The results show that this sea urchin, when its density is low, is estimated to consume about 0.6–18.9% of the seagrass production. However, active movement of consumers among adjacent habitats influences nutrient fluxes. During sea urchin migration, when densities of 10–98 ind. m−² were observed, the consumption rates in sea urchin feeding fronts temporarily exceeded seagrass production rates. The overgrazing of the C. nodosa results in patches where leaves of this plant are completely consumed, and this phenomenon may explain a part of interannual variations in the distribution pattern of this species.
A D Rijnsdorp - One of the best experts on this subject based on the ideXlab platform.
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Fishing Sea-bed Habitat Risk Assessment (A framework towards the quantitative assessment of trawling impact on the sea-bed and Benthic Ecosystem)
2020Co-Authors: A D Rijnsdorp, Francois Bastardie, Stefan G Bolam, Ole Ritzau Eigaard, Katell G Hamon, Jan G Hiddink, Niels T Hintzen, A Ivanovic, Lene Buhl-mortensen, Andrew KennyAbstract:A framework to assess the impact of mobile fishing gear on the seabed and Benthic Ecosystem is presented. The framework that can be used at regional and local scales considers the physical effects of trawl gears on the seabed, on marine taxa and the functioning of the Benthic Ecosystem. A reductionist approach is applied that breaks down a fishing gear in its components and distinguishes a number of biological traits that are chosen to determine the vulnerability of benthos for the impact of a gear component or to provide a proxy for their ecological role. The approach considers a wide variety of gear elements, such as otter boards, twin trawl clump and ground-rope, and, sweeps that herd the fish. The physical impact of these elements on the seabed, comprising scraping of the seabed, sediment mobilisation and penetration, are a function of the mass, size and speed of the individual component. The impact of the elements on the Benthic community are quantified using a biological-trait approach, that considers the vulnerability of the Benthic community to trawl impact (e.g. sediment position, morphology), the recovery rate (e.g. longevity, maturation age, reproductive characteristics) and the ecological role. The framework is explored to compare the indicators for pressure and ecological impact of bottom trawling in three main seabed habitat types in the North Sea. Preliminary results show that the sublittoral mud habitat is impacted most due to the combined effect of an intensive fishing and high proportions of long-lived taxa.
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Report on technological innovations and management scenario’s to mitigate fishing impacts on the Benthic Ecosystem and their socio-economic consequences in regional seas
2020Co-Authors: Antonello Sala, R Nielsen, Hans Polet, Pascal Laffargue, Chris Smith, Mustafa Zengin, A D RijnsdorpAbstract:This report provides a detailed account of the field and modelling studies carried out in the BENTHIS project in the Baltic Sea, North Sea, Western Waters, Mediterranean and Black Sea on the mitigation of bottom trawling impacts on the seafloor and Benthic Ecosystem. The studies were conducted in close collaboration with fishers and gear manufacterers and focused on the major bottom trawl fisheries in European waters: otter trawl fisheries for demersal fish, otter trawl fisheries for Nephrops, beam trawl fisheries for flatfish, beam trawl fisheries for brown shrimps, beam trawl fisheries for whelks, dredge fisheries for bivalves (mussel, scallops). Both technological innovations and alternative management scenarios were explored. Technological innovations The following technological innovations were studied: (i) Lifting otterboards (semi-pelagic otterboards, jumper boards); (ii) Reducing sweep length in Nephrops otter trawls; (iii) Gear modifications (weight, chain, mesh size); (iv) Pulse trawls replacing mechanical stimulation by electrical stimulation; (v) Use of passive gear (creels and pots). Semi-pelagic otterboards New scaled otterboards designed by Italian SMEs (Small and Medium Size Enterprises) were preliminary tested in a wind tunnel and in a flume tank and finally tested in full-scale at sea. Sea trials showed a reduction in fuel cost and bottom contact, while the catch efficiency was not significantly affected. Jumper otterboards, tested in the French Nephrops fishery, produced considerably lower level of sediment re-suspensioncompared to the conventional otterboards, while catch rates were not statistically different. Reduced sweep length Sea trials with reduced sweep length in the Nephrops fishery in the Kattegat (western Baltic) indicated that it is possible to maintain similar catch rate of Nephrops, flatfish (plaice, sole) and codfish (cod, haddock) with shorter sweeps. Gear modifications (gear weight, application of chains, mesh size)...
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Report on results of sea trials in the regional seas
2020Co-Authors: Antonello Sala, A D Rijnsdorp, Hans Polet, Pascal Laffargue, Chris Smith, J. Rasmus Nielsen, Mustafa ZenginAbstract:Each of the regional case studies focus on one or more fisheries that are representative of the region and comprise the full range of fishing gears that are widely used in European waters and are highly relevant in the context of mitigating their impact on Benthic Ecosystems. Case studies identified are the Baltic Sea (Nephrops trawl, Otter trawls for cod, Blue mussel fishery), North Sea (Beam trawl, Shrimp trawl), Western waters (Nephrops trawl, Scallop trawl, Otter trawl on biogenic habitats), Mediterranean Sea (Otter trawl), Black Sea (Rapa whelk fishery with beam trawls and commercial demersal fisheries with bottom trawls). In each of the case studies, a full analysis of a selected fishery including the assessment of the current impact on the Benthic Ecosystem and the assessment of the ecological and economic consequences of technological and management innovations could provide advice, and demonstrate how to mitigate fishery impacts on the Benthic Ecosystem. This report collects all the regional case studies reports related to sea trials carried out to date. Particular attention has been paid to the description of the activities carried out. A preliminary presentation of the results obtained has also been included, even if data collected will be further analysed.
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towards a framework for the quantitative assessment of trawling impact on the seabed and Benthic Ecosystem
Ices Journal of Marine Science, 2016Co-Authors: A D Rijnsdorp, Francois Bastardie, Stefan G Bolam, Lene Buhlmortensen, Ole Ritzau Eigaard, Katell G Hamon, Jan G Hiddink, Niels T Hintzen, A Ivanovic, Andrew KennyAbstract:A framework to assess the impact of mobile fishing gear on the seabed and Benthic Ecosystem is presented. The framework that can be used at regional and local scales provides indicators for both trawling pressure and ecological impact. It builds on high-resolution maps of trawling intensity and considers the physical effects of trawl gears on the seabed, on marine taxa, and on the functioning of the Benthic Ecosystem. Within the framework, a reductionist approach is applied that breaks down a fishing gear into its components, and a number of biological traits are chosen to determine either the vulnerability of the benthos to the impact of that gear component, or to provide a proxy for their ecological role. The approach considers gear elements, such as otter boards, twin trawl clump, and groundrope, and sweeps that herd the fish. The physical impact of these elements on the seabed, comprising scraping of the seabed, sediment mobilization, and penetration, is a function of the mass, size, and speed of the individual component. The impact of the elements on the Benthic community is quantified using a biological-trait approach that considers the vulnerability of the Benthic community to trawl impact (e.g. sediment position, morphology), the recovery rate (e.g. longevity, maturation age, reproductive characteristics, dispersal), and their ecological role. The framework is explored to compare the indicators for pressure and ecological impact of bottom trawling in three main seabed habitat types in the North Sea. Preliminary results show that the Sublittoral mud (EUNIS A5.3) is affected the most due to the combined effect of intensive fishing and large proportions of long-lived taxa
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temporal aggregation of bottom trawling and its implication for the impact on the Benthic Ecosystem
Ices Journal of Marine Science, 2015Co-Authors: Daniel P Van Denderen, Niels T Hintzen, Tobias Van Kooten, A D RijnsdorpAbstract:Understanding trawling impacts on the Benthic Ecosystem depends to a large extent on the ability to estimate trawling activity at the appropriate scale. Several studies have assessed trawling at fine spatial scales yearly, largely ignoring temporal patterns. In this study, we analysed these temporal patterns in beam trawl effort intensity at 90 stations of the Dutch continental shelf of the North Sea for a period of 10 years, at a fine temporal (weekly) and spatial (110 × 70 m) scale using Vessel Monitoring by Satellite (VMS) data. Our results show that trawling is aggregated in time and shows clear seasonality, related to the behavior of the fleet and migration patterns of the target fish species. The temporal patterns affect the overall impact on and the recovery of the Benthic community, as is illustrated with a Benthic population model. Our results imply that trawling impact studies using high-resolution data like VMS should take account of the possibility of temporal aggregation and seasonality in trawling to improve the assessment of the impact of trawling on the population dynamics of benthos.
