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Auteur Ba, A.; Chaboud, C.; Schmidt, J.; Diouf, M.; Fall, M.; Deme, M.; Brehmer, P.
Titre The potential impact of marine protected areas on the Senegalese sardinella fishery Type Article scientifique
Année 2019 Publication Revue Abrégée Ocean Coastal Manage.
Volume 169 Numéro Pages 239-246
Mots-Clés abundance; Aichi targets; Bioeconomic modeling; Fishery management; Fishing capacity; management; mpa; Sardinella aurita; Sardinella maderensis; small pelagic fish; Small scale fisheries; West Africa; west-africa
Résumé In the early 2000s, Senegal set up several Marine Protected Areas (MPAs) along its coastal zone with the purpose of biodiversity conservation and to support sustainable management of fisheries. However, the impact of MPAs may vary according to the type of fisheries. In Senegal, the sardinella fishery accounts for 70% of total catches. This fishery is of crucial importance for national food security and employment. Given this importance, it is necessary to evaluate the impact of MPAs, often being considered as a tool for fisheries management. An analytical, dynamic and spatial bio-economic model of sardinella fishery, considering fish and fisher migration, has been developed and scenarios over forty years have been analyzed. The results show that the fishery is economically overexploited and that Senegal could lose about 11.6 billion CFA over forty years of exploitation, i.e. 290 million CFA per year. To achieve an optimal level of exploitation, it would be necessary to halve the current fishing capacity. Implementing MPAs for 10, 20 and 30% of the Senegalese exclusive economic zone lead to slight increases in biomass (1%) and rent (5-11%). In addition, spatio-temporal closures can lead to increased exploitation in unclosed areas, due to the absence of enforcement. Achieving target 11 of the Aichi Convention, i.e., 10% of coastal and marine areas protected per country, will have a reserve effect on the resource but also only lead to weak improvements in economic indicators for the Senegalese fishery. Finally, because the sardinella resource is shared among many countries of the Sub-Regional Fisheries Commission (SRFC), a sub-regional cooperation is necessary for a sustainable management.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0964-5691 ISBN Médium
Région Expédition Conférence
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2536
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Auteur Bertrand, S.; Joo, R.; Smet, C.A.; Tremblay, Y.; Barbraud, C.; Weimerskirch, H.
Titre Local depletion by a fishery can affect seabird foraging Type Article scientifique
Année 2012 Publication Revue Abrégée Journal of Applied Ecology
Volume 49 Numéro 5 Pages 1168-1177
Mots-Clés competition for prey; fishery management; guano-producing seabirds; Peruvian anchovy
Résumé Long-term demographic studies show that seabird populations may suffer from competition with fisheries. Understanding this process is critical for the implementation of an ecosystem approach to fisheries management (EAF). Existing studies rely mostly on indirect clues: overlaps between seabird foraging and fishing areas, comparing fish catches by seabirds and vessels. The study is based on a GPS tracking experiment performed in 2007 on one of the main guano-producing seabird species, the Peruvian booby, breeding on an island near the major port for anchovy landings in Peru. The fishery, which is entirely monitored by a Vessel Monitoring System, opened the day we began the tracking experiment, providing a unique opportunity to examine the day-to-day effects of an intense fishing activity on seabird foraging behaviour. We observed a significant increase in the range of the daily trips and distances of the dives by birds from the colony. This increase was significantly related to the concomitant fishing activity. Seabirds progressively became more segregated in space from the vessels. Their increased foraging effort was significantly related to the growing quantity of anchovy removals by the fishery. In addition, daily removals by the fishery were at least 100 times greater than the daily anchovy requirement of the seabird colonies. We conclude that seabirds needed to forage farther to cope with the regional prey depletion created by the intensive fishing behaviour of this open access fishery. Synthesis and applications. We show that the foraging efficiency of breeding seabirds may be significantly affected by not only the global quantity, but also the temporal and spatial patterns of fishery removals. Together with an ecosystem-based definition of the fishery quota, an EAF should limit the risk of local depletion around breeding colonies using, for instance, adaptive marine protected areas.
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Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0021-8901 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 172
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Auteur Blanchard, F.; Chaboud, C.; Thebaud, O.
Titre Back to the future: A retrospective assessment of model-based scenarios for the management of the shrimp fishery in French Guiana facing global change Type Article scientifique
Année Publication Revue Abrégée Nat. Resour. Model.
Volume Numéro Pages e12232
Mots-Clés bio-economic model; climate change; numerical simulation; retrospective analysis; seafood market; tropical shrimp fishery; uncertainty
Résumé While the number of models dedicated to predicting the consequences of alternative resource management strategies has increased, instances in which authors look back at past predictions to learn from discrepancies between these and observed developments are scarce. In the past decades, the French Guiana shrimp fishery has experienced shrimp market globalization and decreasing levels of shrimp recruitment due to environmental changes. In 2006, a bio-economic model of this fishery was developed to simulate its possible responses to economic and environmental scenarios up to 2016. Here, we compare here these predictions to the observed trajectories. While the number of active vessels corresponds to that which was predicted, the estimated shrimp stock does not. Important driving factors had not been anticipated, including a general strike, natural disasters, and the end of the global financial crisis. These results show the importance of participative approaches involving stakeholders in the co-construction and shared representation of scenarios. Recommendations for resource managers Effective fisheries resources management and a fortiori, the capacity of the fisheries to adapt to global change, requires understanding of both ecological and economics dynamics. The temporal trajectory of the trawling shrimp fisheries has been well monitored, and the decline of both stock and fleet is understood regarding ecological and economic changes: Changes in the environmental conditions of shrimp recruitment, and oil price increase and selling price decrease. However, our bio-economic modeling work showed that, even with a good understanding of the dynamics explaining past trajectories, unpredictable events (strike, natural disasters horizontal ellipsis ) have acted as other key driving factors altering the capacity of the model to represent possible futures. These results led us to recommend a better integration of the expertise of social and political scientists in developing models of bio-economic systems to increase the quality of scenario predictions, and to argue for more participative approaches involving the stakeholders.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0890-8575 ISBN Médium
Région Expédition Conférence
Notes WOS:000476048000001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2618
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Auteur Bourjea, J.; Clermont, S.; Delgado, A.; Murua, H.; Ruiz, J.; Ciccione, S.; Chavance, P.
Titre Marine turtle interaction with purse-seine fishery in the Atlantic and Indian oceans: Lessons for management Type Article scientifique
Année 2014 Publication Revue Abrégée Biological Conservation
Volume 178 Numéro Pages 74-87
Mots-Clés Atlantic Ocean; Bycatch; Fishery impacts; fishery management; Indian Ocean; Marine turtle
Résumé Bycatch of endangered marine turtles is a growing issue for the management of all fisheries, including the oceanic purse-seine fishery. The aim of this study was to assess the spatial and temporal variation in bycatch rates of these species in the entire European purse-seine fishery operating in the Atlantic and Indian oceans. The study was based on data collected through observer programs from 1995 to 2011. During that period, a total of 15 913 fishing sets were observed, including 6 515 on Drifting Fish Aggregating Devices (DFADs) and 9 398 on free swimming schools, representing a global coverage of 10.3% and 5.1% of the total fishing activity in the Atlantic and Indian Ocean, respectively. Moreover, from 2003 to 2011, 14 124 specific observations were carried out on DFADs to check turtle entanglement in the net covering DFADs. We found that the purse-seine fishery has a very low impact on marine turtles. We estimated that the annual number of individuals incidentally captured was 218 (SD = 150) and 250 (SD = 157) in the Atlantic and Indian Ocean, respectively, with more than 75% being released alive. The present study also investigated the impact of DFADs; which is considered a key conservation issue for this fishery. Drifting objects may play a key role in aggregating juveniles of marine turtles, implying the need for improving their construction to avoid entanglement (e.g. avoiding nets in the structure); however, based on our study it is not the main source of incidental captures of marine turtles in this fishery.
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Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0006-3207 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 349
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Auteur Coelho, R.; Mejuto, J.; Domingo, A.; Yokawa, K.; Liu, K.-M.; Cortes, E.; Romanov, E.V.; da Silva, C.; Hazin, F.; Arocha, F.; Mwilima, A.M.; Bach, P.; Ortiz de Zarate, V.; Roche, W.; Lino, P.G.; Garcia-Cortes, B.; Ramos-Cartelle, A.M.; Forselledo, R.; Mas, F.; Ohshimo, S.; Courtney, D.; Sabarros, P.S.; Perez, B.; Wogerbauer, C.; Tsai, W.-P.; Carvalho, F.; Santos, M.N.
Titre Distribution patterns and population structure of the blue shark (Prionace glauca) in the Atlantic and Indian Oceans Type Article scientifique
Année 2018 Publication Revue Abrégée Fish. Fish.
Volume 19 Numéro 1 Pages 90-106
Mots-Clés Atlantic Ocean; Indian Ocean; size distribution; spatial distribution; relative abundance; north-atlantic; caribbean sea; elasmobranchs caught; fishery observer programmes; pelagic fisheries; pelagic sharks
Résumé The blue shark (Prionace glauca) is the most frequently captured shark in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. As part of cooperative scientific efforts for fisheries and biological data collection, information from fishery observers, scientific projects and surveys, and from recreational fisheries from several nations in the Atlantic and Indian Oceans was compiled. Data sets included information on location, size and sex, in a total of 478,220 blue shark records collected between 1966 and 2014. Sizes ranged from 36 to 394cm fork length. Considerable variability was observed in the size distribution by region and season in both oceans. Larger blue sharks tend to occur in equatorial and tropical regions, and smaller specimens in higher latitudes in temperate waters. Differences in sex ratios were also detected spatially and seasonally. Nursery areas in the Atlantic seem to occur in the temperate south-east off South Africa and Namibia, in the south-west off southern Brazil and Uruguay, and in the north-east off the Iberian Peninsula and the Azores. Parturition may occur in the tropical north-east off West Africa. In the Indian Ocean, nursery areas also seem to occur in temperate waters, especially in the south-west Indian Ocean off South Africa, and in the south-east off south-western Australia. The distributional patterns presented in this study provide a better understanding of how blue sharks segregate by size and sex, spatially and temporally, and improve the scientific advice to help adopt more informed and efficient management and conservation measures for this cosmopolitan species.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1467-2960 ISBN Médium
Région Expédition Conférence
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Numéro d'Appel MARBEC @ alain.herve @ collection 2253
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