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Auteur (up) Rouyer, T.; Sadykov, A.; Ohlberger, J.; Stenseth, N.C.
Titre Does increasing mortality change the response of fish populations to environmental fluctuations? Type Article scientifique
Année 2012 Publication Revue Abrégée Ecology Letters
Volume 15 Numéro 7 Pages 658-665
Mots-Clés Age-structured populations; climate-fishing interaction; demographic change; exploited fish stocks; frequency response; response to the environment
Résumé Ecology Letters (2012) 15: 658–665 Abstract

Fluctuations of fish populations abundances are shaped by the interplay between population dynamics and the stochastic forcing of the environment. Age-structured populations behave as a filter of the environment. This filter is characterised by the species-specific life cycle and life-history traits. An increased mortality of mature individuals alters these characteristics and may therefore induce changes in the variability of populations. The response of a generic age-structured model was analysed to investigate the expected changes in the fluctuations of fish populations in response to decreased adult survival. These expectations were then tested on an extensive dataset. In accordance with theory, the analyses revealed that decreased adult survival and mean age of spawners were linked to an increase in the relative importance of short-term fluctuations. It suggests that intensive exploitation can lead to a change in the variability of fish populations, an issue of central interest from both conservation and management perspectives.
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ISSN 1461-0248 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1666
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Auteur (up) Shannon, L.J.; Coll, M.; Yemane, D.; Jouffre, D.; Neira, S.; Bertrand, A.; Diaz, E.; Shin, Y.J.
Titre Comparing data-based indicators across upwelling and comparable systems for communicating ecosystem states and trends Type Article scientifique
Année 2010 Publication Revue Abrégée ICES J. Mar. Sci.
Volume 67 Numéro 4 Pages 807-832
Mots-Clés adriatic sea; central chile; comparative approach; demersal resources; fishing impacts; food-web; global fisheries; humboldt current system; indicator; nw mediterranean sea; pelagic fish; regime shifts; southern benguela; upwelling
Résumé Shannon, L. J., Coll, M., Yemane, D., Jouffre, D., Neira, S., Bertrand, A., Diaz, E., and Shin, Y-J. 2010. Comparing data-based indicators across upwelling and comparable systems for communicating ecosystem states and trends. – ICES Journal of Marine Science, 67: 807-832.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1054-3139 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 482
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Auteur (up) Shin, Y.-J.; Shannon, L.J.
Titre Using indicators for evaluating, comparing, and communicating the ecological status of exploited marine ecosystems. 1. The IndiSeas project Type Article scientifique
Année 2010 Publication Revue Abrégée Ices Journal of Marine Science
Volume 67 Numéro Pages 686-691
Mots-Clés approach; comparative; ecosystem; Fishing; impacts; indicator; IndiSeas; marine; status
Résumé One of the challenges faced by the scientific community grappling with the ecosystem approach to fisheries is to propose a generic set of synthetic ecological indicators, which would accurately reflect the effects of fisheries on marine ecosystems, and could support sound communication and management practices. The IndiSeas Working Group was established in 2005 under the auspices of the Eur-Oceans Network of Excellence to develop methods to provide indicators-based assessments of the status of exploited marine ecosystems in a comparative framework. Here, we present the two main outputs of the first phase of the project: a suite of papers documenting a combination of indicator-based methods and results comparing the ecological status of the world's exploited marine ecosystems, and a website aiming to communicate these results beyond scientific audiences.
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ISSN 1054-3139 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 106
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Auteur (up) Shin, Y.-J.; Shannon, L.J.; Bundy, A.; Coll, M.; Aydin, K.; Bez, N.; Blanchard, J.L.; Borges, M.D.; Diallo, I.; Diaz, E.; Heymans, J.J.; Hill, L.; Johannesen, E.; Jouffre, D.; Kifani, S.; Labrosse, P.; Link, J.S.; Mackinson, S.; Masski, H.; Mollmann, C.; Neira, S.; Ojaveer, H.; Abdallahi, K.O.M.; Perry, I.; Thiao, D.; Yemane, D.; Cury, P.
Titre Using indicators for evaluating, comparing, and communicating the ecological status of exploited marine ecosystems. 2. Setting the scene Type Article scientifique
Année 2010 Publication Revue Abrégée Ices Journal of Marine Science
Volume 67 Numéro 4 Pages 692-716
Mots-Clés comparative approach; ecological indicators; ecosystem effects of fishing; exploited marine ecosystems; IndiSeas
Résumé Background is provided to the selection of ecological indicators by the IndiSeas Working Group, and the methodology adopted for analysis and comparison of indicators across exploited marine ecosystems is documented. The selected indicators are presented, how they are calculated is explained, and the philosophy behind the comparative approach is given. The combination of selected indicators is intended to reflect different dynamics, tracking processes that display differential responses to fishing, and is meant to provide a complementary means of assessing marine ecosystem trends and states. IndiSeas relied on inputs and insights provided by the local experts from participating ecosystems, helping to understand state and trend indicators and to disentangle the effect of other potential ecosystem drivers, such as climate variability. This project showed that the use of simple and available indicators under an ecosystem approach can achieve a real, wide-reaching evaluation of marine ecosystem status caused by fishing. This is important because the socio-economics of areas where fishing activities develop differs significantly around the globe, and in many countries, insufficient data are available for complex and exhaustive analyses.
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Langue Langue du Résumé Titre Original
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ISSN 1054-3139 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 107
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Auteur (up) Torres-Irineo, E.; Dreyfus-Leon, M.; Gaertner, D.; Salas, S.; Marchal, P.
Titre Adaptive responses of tropical tuna purse-seiners under temporal regulations Type Article scientifique
Année 2017 Publication Revue Abrégée Ambio
Volume 46 Numéro 1 Pages 88-97
Mots-Clés atlantic; behavior; Closed season; eastern pacific-ocean; eastern tropical pacific; Fisher behaviour; Fisheries management; fishing strategies; fleet dynamics; mixed fisheries; model; Purse-seine fishing; state; trawlers; Tropical tuna
Résumé The failure to achieve fisheries management objectives has been broadly discussed in international meetings. Measuring the effects of fishery regulations is difficult due to the lack of detailed information. The yellowfin tuna fishery in the eastern Pacific Ocean offers an opportunity to evaluate the fishers' responses to temporal regulations. We used data from observers on-board Mexican purse-seine fleet, which is the main fleet fishing on dolphin-associated tuna schools. In 2002, the Inter-American Tropical Tuna Commission implemented a closed season to reduce fishing effort for this fishery. For the period 1992-2008, we analysed three fishery indicators using generalized estimating equations to evaluate the fishers' response to the closure. We found that purse-seiners decreased their time spent in port, increased their fishing sets, and maintained their proportion of successful fishing sets. Our results highlight the relevance of accounting for the fisher behaviour to understand fisheries dynamics when establishing management regulations.
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Langue English Langue du Résumé Titre Original
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ISSN 0044-7447 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2072
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