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Auteur Batsleer, J.; Marchal, P.; Vaz, S.; Vermard, V.; Rijnsdorp, A.D.; Poos, J.J. doi  openurl
  Titre Exploring habitat credits to manage the benthic impact in a mixed fishery Type Article scientifique
  Année 2018 Publication Revue Abrégée Mar. Ecol.-Prog. Ser.  
  Volume (down) 586 Numéro Pages 167-179  
  Mots-Clés growth; sea; reserves; marine protected areas; juvenile; Plaice; Eastern English Channel; Fleet dynamics; vms data; fishing disturbance; central english-channel; Cod; costs; Dynamic state variable modelling; georges bank; Mixed fisheries; tac; Total allowable catch  
  Résumé The performance of a combined catch quota and habitat credit system was explored to manage the sustainable exploitation of a mix of demersal fish species and reduce the benthic impacts of bottom trawl fisheries using a dynamic state variable model approach. The model was parameterised for the Eastern English Channel demersal mixed fishery using otter trawls or dredges. Target species differed in their association with habitat types. Restricting catch quota for plaice and cod had a limited effect on benthic impact, except when reduced to very low values, forcing the vessels to stay in port. Quota management had a minimal influence on fishing behaviour and hence resulted in a minimal reduction of benthic impact. Habitat credits may reduce the benthic impacts of the trawl fisheries at a minimal loss of landings and revenue, as vessels are still able to reallocate their effort to less vulnerable fishing grounds, while allowing the fishery to catch their catch quota and maintain their revenue. Only if they are reduced to extremely low levels can habitat credits potentially constrain fishing activities to levels that prevent the fisheries from using up the catch quota for the target species.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0171-8630 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2283  
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Auteur Albo-Puigserver, M.; Navarro, J.; Coll, M.; Aguzzi, J.; Cardona, L.; Saez-Liante, R. doi  openurl
  Titre Feeding ecology and trophic position of three sympatric demersal chondrichthyans in the northwestern Mediterranean Type Article scientifique
  Année 2015 Publication Revue Abrégée Mar. Ecol.-Prog. Ser.  
  Volume (down) 524 Numéro Pages 255-268  
  Mots-Clés Chimaera monstrosa; chimera-monstrosa; discrimination factors; Etmopterus spinax; etmopterus-spinax linnaeus; Feeding niche; fishing impacts; food-web; Galeus melastomus; galeus-melastomus; interpreting stable-isotopes; Isotope analysis; Mediterranean Sea; portuguese continental-slope; sea; top predators  
  Résumé Understanding how marine predators interact is a scientific challenge. In marine ecosystems, segregation in feeding habits has been largely described as a common mechanism to allow the coexistence of several competing marine predators. However, little is known about the feeding ecology of most species of chondrichthyans, which play a pivotal role in the structure of marine food webs worldwide. In this study, we examined the trophic ecology of 3 relatively abundant chondrichthyans coexisting in the Mediterranean Sea: the blackmouth catshark Galeus melastomus, the velvet belly lanternshark Etmopterus spinax and the rabbit fish Chimaera monstrosa. To examine their trophic ecology and interspecific differences in food habits, we combined the analysis of stomach content and stable isotopes. Our results highlighted a trophic segregation between C. monstrosa and the other 2 species. G. melastomus showed a diet composed mainly of cephalopods, while E. spinax preyed mainly on shrimps and C. monstrosa on crabs. Interspecific differences in the trophic niche were likely due to different feeding capabilities and body size. Each species showed different isotopic niche space and trophic level. Specifically, C. monstrosa showed a higher trophic level than E. spinax and G. melastomus. The high trophic levels of the 3 species highlighted their important role as predators in the marine food web. Our results illustrate the utility of using complementary approaches that provide information about the feeding behaviour at short (stomach content) and long-term scales (stable isotopes), which could allow more efficient monitoring of marine food-web changes in the study area.  
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  ISSN 0171-8630 ISBN Médium  
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Auteur Fu, C.; Travers-Trolet, M.; Velez, L.; Grüss, A.; Bundy, A.; Shannon, L.J.; Fulton, E.A.; Akoglu, E.; Houle, J.E.; Coll, M.; Verley, P.; Heymans, J.J.; John, E.; Shin, Y.-J. url  doi
openurl 
  Titre Risky business: The combined effects of fishing and changes in primary productivity on fish communities Type Article scientifique
  Année 2018 Publication Revue Abrégée Ecological Modelling  
  Volume (down) 368 Numéro Pages 265-276  
  Mots-Clés Combined effect; Fishing; Marine ecosystem; Meta-analysis; Multiple drivers; Synergism  
  Résumé There is an increasing need to understand community-level or whole-ecosystem responses to multiple stressors since the impacts of multiple stressors on marine systems depend not only on species-level responses, but also on species interactions and ecosystem structure. In this study, we used a multi-model ecosystem simulation approach to explore the combined effects of fishing and primary productivity on different components of the food-web across a suite of ecosystems and a range of model types. Simulations were carried out under different levels of primary productivity and various fishing scenarios (targeting different trophic levels). Previous work exploring the effects of multiple stressors often assumed that the combined effects of stressors are additive, synergistic or antagonistic. In this study, we included a fourth category “dampened”, which refers to less negative or to less positive impacts on a given ecosystem component compared to additive effects, and in contrast to previous studies, we explicitly considered the direction of the combined effects (positive or negative). We focused on two specific combined effects (negative synergism and positive dampened) associated with the ecological risk of resultant lower fish biomass than expected under additive effects. Through a meta-analysis of the multi-models’ simulation results, we found that (i) the risk of negative synergism was generally higher for low-trophic-level (LTL) taxa, implying that following an increase of fishing pressure on a given LTL stock, the subsequent decrease of biomass under low primary productivity would be higher than expected when fishing is the sole driver and (ii) the risk of positive dampened effects was generally higher for high-trophic-level (HTL) taxa, implying that given a management measure aimed at reducing the impact of fishing on HTL stocks, the subsequent rebuilding of these stocks would be slower than expected if only fishing were considered. Our approach to categorizing and exploring cumulative risk can be applied to evaluate other community properties and indicators and our findings could provide guidance in fisheries management.  
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  ISSN 0304-3800 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2235  
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Auteur Grüss, A.; Harford, W.J.; Schirripa, M.J.; Velez, L.; Sagarese, S.R.; Shin, Y.-J.; Verley, P. url  doi
openurl 
  Titre Management strategy evaluation using the individual-based, multispecies modeling approach OSMOSE Type Article scientifique
  Année 2016 Publication Revue Abrégée Ecological Modelling  
  Volume (down) 340 Numéro Pages 86-105  
  Mots-Clés Ecosystem modeling; end-to-end model; Gulf of Mexico; Management strategy evaluation; Risk of overfishing; Total acceptable catch  
  Résumé End-to-end ecosystem modeling platforms, including OSMOSE, are key tools for informing ecosystem-based fisheries management (EBFM). End-to-end models ideally implement two-way interactions between model components, yet two-way interactions between high trophic level (HTL) functional groups and humans (fisheries managers and fishers) are currently missing in OSMOSE. We developed a management strategy evaluation (MSE) framework for OSMOSE, which allows for feedback between HTL functional groups and fisheries managers. This framework couples OSMOSE to a management procedure integrating decision rules and accounting for scientific uncertainty and the acceptable risk of overfishing. We applied the MSE framework to the OSMOSE model of the West Florida Shelf, so as to conduct an evaluation of total allowable catch (TAC) strategies for red grouper (Epinephelus morio) in a context of episodic events of natural mortality. Our simulations indicate that TAC strategies that assume higher scientific uncertainty and/or lower acceptable risk of overfishing result in higher biomass-related metrics for red grouper. However, the levels of scientific uncertainty and acceptable risk of overfishing impose a trade-off between biomass-related and catch-related metrics for red grouper. Our simulations also indicate that updating red grouper TAC more frequently in a context of episodic events of natural mortality does not have a large impact on biomass-related and catch-related metrics for red grouper and other functional groups. The MSE we conducted for red grouper is strategic, and its outcomes, which were obtained under a specific set of assumptions, must be considered preliminary. We discuss how future research could help enhance understanding of the possible impacts of TAC strategies for red grouper. The MSE framework designed for OSMOSE links the dynamics of HTL functional groups to that of fisheries managers, thereby allowing OSMOSE to be better suited for informing EBFM. This framework is an invaluable asset in assessing the performance of fisheries management strategies, but could also be used for other purposes, such as the evaluation of research monitoring programs.  
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  Éditeur de collection Titre de collection Titre de collection Abrégé  
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  ISSN 0304-3800 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1615  
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Auteur Coll, M.; Steenbeek, J.; Sole, J.; Palomera, I.; Christensen, V. doi  openurl
  Titre Modelling the cumulative spatial-temporal effects of environmental drivers and fishing in a NW Mediterranean marine ecosystem Type Article scientifique
  Année 2016 Publication Revue Abrégée Ecol. Model.  
  Volume (down) 331 Numéro Pages 100-114  
  Mots-Clés acoustic estimation; anchovy engraulis-encrasicolus; climate-change; Cumulative effects; Ecopath with Ecosim; environment; european hake; exploited ecosystems; fishing; food-web model; food webs; hake merluccius-merluccius; protected areas; south catalan sea; trawling disturbance  
  Résumé To realistically predict spatial-temporal dynamics of species in marine ecosystems it is essential to consider environmental conditions in conjunction with human activities and food web dynamics. In this study, we used Ecospace, the spatial-temporal dynamic module of Ecopath with Ecosim (EwE) food web model, to drive a spatially explicit marine food web model representing the Southern Catalan Sea (NW Mediterranean) with various environmental drivers and with fishing. We then evaluated the individual and joint effects of environmental conditions and fishing in various compartments of the food web. First we used a previously developed EwE model fitted to time series of data from 1978 to 2010 as a baseline configuration. The model included 40 functional groups and four fishing fleets. We first ran the original Ecospace spatial-temporal dynamic model using the original habitat configuration, in addition to fishing, and we predicted species distributions and abundances. Afterwards, we ran the new habitat foraging capacity model using the most important environmental drivers linked with the Ebro River delta dynamics (salinity, temperature, and primary production), in addition to depth, substrate and fishing, and we compared results with those from the original implementation of Ecospace. Three commercial species, European hake (Merluccius merluccius), anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus), were used to analyse results. Species distributions more closely matched the empirical information available from the study area when using the new habitat capacity model. Results suggested that the historical impacts of fishing and environmental conditions on the biomass and distributions of hake, anchovy and sardine were not additive, but mainly cumulative with a synergistic or antagonistic effect. Fishing had the highest impact on spatial modelling results while the spatial distribution of primary producers and depth followed in importance. This study contributes to the development of more reliable predictions of regional change in marine ecosystems of the Mediterranean Sea. (C) 2016 Elsevier B.V. All rights reserved.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
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  ISSN 0304-3800 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1643  
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