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Auteur (up) Foveau, A.; Vaz, S.; Desroy, N.; Kostylev, V.E.
Titre Process-driven and biological characterisation and mapping of seabed habitats sensitive to trawling Type Article scientifique
Année 2017 Publication Revue Abrégée PLoS One
Volume 12 Numéro 10 Pages e0184486
Mots-Clés beam trawl; benthic communities; british-isles; continental-shelf; english-channel; fishing disturbance; impact; north-sea; scotian shelf; taxonomic sufficiency
Résumé The increase of anthropogenic pressures on the marine environment together with the necessity of a sustainable management of marine living resources have underlined the need to map and model coastal environments, particularly for the purposes of spatial planning and for the implementation of integrated ecosystem-based management approach. The present study compares outputs of a process-driven benthic habitat sensitivity (PDS) model to the structure, composition and distribution of benthic invertebrates in the Eastern English Channel and southern part of the North Sea. Trawl disturbance indicators (TDI) computed from species biological traits and benthic community composition were produced from samples collected with a bottom trawl. The TDI was found to be highly correlated to the PDS further validating the latter's purpose to identify natural process-driven pattern of sensitivity. PDS was found to reflect an environmental potential that may no longer be fully observable in the field and difference with in situ biological observations could be partially explained by the spatial distribution of fishery pressure on the seafloor. The management implication of these findings are discussed and we suggest that, used in conjunction with TDI approaches, PDS may help monitor management effort by evaluating the difference between the current state and the presumed optimal environmental status of marine benthic habitats.
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Langue English Langue du Résumé Titre Original
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ISSN 1932-6203 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2202
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Auteur (up) Freon, P.; Avadi, A.; Chavez, R.A.V.; Ahon, F.I.
Titre Life cycle assessment of the Peruvian industrial anchoveta fleet : boundary setting in life cycle inventory analyses of complex and plural means of production Type Article scientifique
Année 2014 Publication Revue Abrégée International Journal of Life Cycle Assessment
Volume 19 Numéro 5 Pages 1068-1086
Mots-Clés Attributional LCA; Complex production system; Environmental impacts; Fishing vessel; Fuel use; Life cycle inventory
Résumé This work has two major objectives: (1) to perform an attributional life cycle assessment (LCA) of a complex mean of production, the main Peruvian fishery targeting anchoveta (anchovy) and (2) to assess common assumptions regarding the exclusion of items from the life cycle inventory (LCI). Data were compiled for 136 vessels of the 661 units in the fleet. The functional unit was 1 t of fresh fish delivered by a steel vessel. Our approach consisted of four steps: (1) a stratified sampling scheme based on a typology of the fleet, (2) a large and very detailed inventory on small representative samples with very limited exclusion based on conventional LCI approaches, (3) an impact assessment on this detailed LCI, followed by a boundary-refining process consisting of retention of items that contributed to the first 95 % of total impacts and (4) increasing the initial sample with a limited number of items, according to the results of (3). The life cycle impact assessment (LCIA) method mostly used was ReCiPe v1.07 associated to the ecoinvent database. Some items that are usually ignored in an LCI's means of production have a significant impact. The use phase is the most important in terms of impacts (66 %), and within that phase, fuel consumption is the leading inventory item contributing to impacts (99 %). Provision of metals (with special attention to electric wiring which is often overlooked) during construction and maintenance, and of nylon for fishing nets, follows. The anchoveta fishery is shown to display the lowest fuel use intensity worldwide. Boundary setting is crucial to avoid underestimation of environmental impacts of complex means of production. The construction, maintenance and EOL stages of the life cycle of fishing vessels have here a substantial environmental impact. Recommendations can be made to decrease the environmental impact of the fleet.
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Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0948-3349 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1148
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Auteur (up) 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.
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 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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Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0304-3800 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2235
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Auteur (up) Fu, C.; Xu, Y.; Bundy, A.; Grüss, A.; Coll, M.; Heymans, J.J.; Fulton, E.A.; Shannon, L.; Halouani, G.; Velez, L.; Akoğlu, E.; Lynam, C.P.; Shin, Y.-J.
Titre Making ecological indicators management ready: Assessing the specificity, sensitivity, and threshold response of ecological indicators Type Article scientifique
Année 2019 Publication Revue Abrégée Ecological Indicators
Volume 105 Numéro Pages 16-28
Mots-Clés Ecological modelling; Fishing pressure; Gradient forest method; Indictor performance; Marine ecosystem; Primary productivity
Résumé Moving toward ecosystem-based fisheries management (EBFM) necessitates a suite of ecological indicators that are responsive to fishing pressure, capable of tracking changes in the state of marine ecosystems, and related to management objectives. In this study, we employed the gradient forest method to assess the performance of 14 key ecological indicators in terms of specificity, sensitivity and the detection of thresholds for EBFM across ten marine ecosystems using four modelling frameworks (Ecopath with Ecosim, OSMOSE, Atlantis, and a multi-species size-spectrum model). Across seven of the ten ecosystems, high specificity to fishing pressure was found for most of the 14 indicators. The indicators biomass to fisheries catch ratio (B/C), mean lifespan and trophic level of fish community were found to have wide utility for evaluating fishing impacts. The biomass indicators, which have been identified as Essential Ocean Variables by the Global Ocean Observing System (GOOS), had lower performance for evaluating fishing impacts, yet they were most sensitive to changes in primary productivity. The indicator B/C was most sensitive to low levels of fishing pressure with a generally consistent threshold response around 0.4*FMSY (fishing mortality rate at maximum sustainable yield) across nine of the ten ecosystems. Over 50% of the 14 indicators had threshold responses at, or below ∼0.6* FMSY for most ecosystems, indicating that these ecosystems would have already crossed a threshold for most indicators when fished at FMSY. This research provides useful insights on the performance of indicators, which contribute to facilitating the worldwide move toward EBFM.
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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 1470-160x ISBN Médium
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Notes WOS:000490574200003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2579
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Auteur (up) Gaertner, D.
Titre Estimates of historic changes in total mortality and selectivity for Eastern Atlantic skipjack (Katsuwonus pelamis) from length composition data Type Article scientifique
Année 2010 Publication Revue Abrégée Aquatic Living Resources
Volume 23 Numéro Pages 3-11
Mots-Clés analysis; Bayesian; change-point; Fad; Fishing; Mortality; rate; Skipjack; strategies; tuna
Résumé Catch-at-size data of the eastern Atlantic skipjack were used to estimate changes in total mortality from 1969 to 2007. We used a transitional model of mean length that generalized the Beverton-Holt mortality estimator to allow change in mortality rate under nonequilibrium conditions. Then, from homogeneous periods of time, length-converted catch curves were used to access qualitative changes in selectivity patterns for two surface fisheries (the baitboat fishery operating from Dakar, Senegal, and the European and associated purse seine fisheries). To explore the impact of catch on the mortality rate, a Bayesian change-point analysis was conducted on the catch time series to detect concomitant variation between mortality rates and catch. Finally, potential causes of these changes are discussed in relation to the implementation of new fishing technology, such fish aggregating devices (FAD). The general pattern depicted by total mortality is in agreement with previous knowledge on this fishery: a state of complete or practically complete exploitation during the nineties followed by the decrease in nominal purse seine fishing effort in the last decade, combined with the effect of a seasonal moratorium on FAD fishing operations. There was no evidence of a change in selectivity between the two contrasted periods of time considered: 1969-1979 and 1986-1999; the second period being characterized by the introduction of new technology onboard vessels. In contrast, the covariation over time between total catch and mortality rate three years later highlights the effect of the fishing pressure on the stock of eastern Atlantic skipjack.
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Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
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ISSN 0990-7440 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 74
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