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Auteur Putman, N.F.; Abreu-Grobois, F.A.; Broderick, A.C.; Ciofi, C.; Formia, A.; Godley, B.J.; Stroud, S.; Pelembe, T.; Verley, P.; Williams, N.
Titre Numerical dispersal simulations and genetics help explain the origin of hawksbill sea turtles in Ascension Island Type (down) Article scientifique
Année 2014 Publication Revue Abrégée Journal of Experimental Marine Biology and Ecology
Volume 450 Numéro Special Issue Pages 98-108
Mots-Clés dispersal; mtDNA; ocean circulation model; Sea turtle
Résumé Long-distance dispersal and ontogenetic shifts in habitat use are characteristic of numerous marine species and have important ecological, evolutionary, and management implications. These processes, however, are often challenging to study due to the vast areas involved. We used genetic markers and simulations of physical transport within an ocean circulation model to gain understanding into the origin ofjuvenile hawksbill sea turtles (Eretmochelys imbricata) found at Ascension Island, a foraging ground that is thousands of kilometers from known nesting beaches. Regional origin of genetic markers suggests that turtles are from Western Atlantic (86%) and Eastern Atlantic (14%) rookeries. In contrast, numerical simulations of transport by ocean currents suggest that passive dispersal from the western sources would be negligible and instead would primarily be from the East, involving rookeries along Western Africa (i.e., Principe Island) and, potentially, from as far as the Indian Ocean (e.g., Mayotte and the Seychelles). Given that genetic analysis identified the presence of a haplotype endemic to Brazilian hawksbill rookeries at Ascension, we examined the possible role of swimming behavior by juvenile hawksbills from NE Brazil on their current-borne transport to Ascension Island by performing numerical experiments in which swimming behavior was simulated for virtual particles (simulated turtles). We found that oriented swimming substantially influenced the distribution of particles, greatly altering the proportion of particles dispersing into the North Atlantic and South Atlantic. Assigning location-dependent orientation behavior to particles allowed them to reach Ascension Island, remain in favorable temperatures, encounter productive foraging areas, and return to the vicinity of their natal site. The age at first arrival to Ascension (4.5-5.5 years) of these particles corresponded well to estimates of hawksbill age based on their size. Our findings suggest that ocean currents and swimming behavior play an important role in the oceanic ecology of sea turtles and other marine animals.
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ISSN 0022-0981 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 333
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Auteur Narchi, N.E.; Cornier, S.; Canu, D.M.; Aguilar-Rosas, L.E.; Bender, M.G.; Jacquelin, C.; Thiba, M.; Moura, G.G.M.; De Wit, R.
Titre Marine ethnobiology a rather neglected area, which can provide an important contribution to ocean and coastal management Type (down) Article scientifique
Année 2014 Publication Revue Abrégée Ocean & Coastal Management
Volume 89 Numéro Pages 117-126
Mots-Clés
Résumé Abstract

This report describes marine ethnobiology as it has been presented and discussed under the conference session “Ethnothalassic interactions” organized for the 13th International Congress of Ethnobiology. We define marine ethnobiology as a field within ethnobiology that specifically comprises the study of the relationships of present and past human societies to marine biota and ecosystems. The session stimulated discussion on this emerging field and its contribution to coastal and ocean management, by exchanging experiences on a diverse array of studies within this field that include: co-management of marine protected areas, seascape management, demise, re-discovery and re-implementation of traditional knowledge-based management schemes, history of artisanal shellfish-farming and of the management of artisanal fisheries, medicinal knowledge of algae, as well as the outreach of ethnobiological studies for the conservation of the cultural-ecological heritage in the coastal zone. We here offer the conclusions of the conference session in the form of a longue duree perspective on coastal management that highlights a broad array of human adaptations to coastal environments. We suggest that these adaptations have to be researched and understood in detail in order to incorporate them into broader coastal management strategies in the presence of the severe environmental and political-economical pressures that currently threaten fishing stocks, marine habitats, and the livelihoods of the 2.6 billion people that depend on the oceans as their main source of protein.
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ISSN 0964-5691 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1358
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Auteur Torres-Irineo, E.; Gaertner, D.; Chassot, E.; Dreyfus-Leon, M.
Titre Changes in fishing power and fishing strategies driven by newtechnologies : the case of tropical tuna purse seiners in the easternAtlantic Ocean Type (down) Article scientifique
Année 2014 Publication Revue Abrégée Fisheries Research
Volume 155 Numéro Pages 10-19
Mots-Clés
Résumé Technological advancements can influence both the fishing power of a fleet and the fishing strategies itemploys. To investigate these potential linkages, we examined almost three decades of data (1981&8211;2008)from French tropical tuna purse seiners operating in the eastern Atlantic Ocean. Applying a sequence ofstatistical methods at different temporal and spatial scales, we analyzed two indicators of fishing power(sets per boat-day on fish aggregating devices (FADs) and sets per boat-day on free-swimming schools)each of which represent a distinct fishing mode. Our results show that the increasing modernizationof this fleet has led to increases in both fishing power and the available number of fishing strategies tochoose from. A key output of this analysis was the breakdown of fishing power time series (for each fishingmode) into separate periods of continuous years during which catchability was assumed to be constant,thus identifying regime shifts. This partitioning allowed us to identify when key changes occurred inthe fishery. Changes in FAD-associated fishing were mostly driven by the introduction of radio beacons(early 1990s) which lead to an increase in fishing effort and an expansion of fishing grounds (directeffect) and the implementation of time-area management measures which resulted in a fragmentationof the traditional fishing grounds in the 2000s (indirect effect). During the same period, fishing on free-swimming schools also increased despite the biomass of stocks decreasing and fishing grounds remainingunchanged. This suggests these increases were driven by improvements in fish detection technology (e.g.,bird radars, sonar). These identified increases are not entirely unexpected: indeed it is widely recognizedthat fishing power in the purse seine tuna fishery has increased over time. However, these increases donot necessarily occur linearly. Thus, understanding how fishing power is changing over time (such asdetermining when regime shifts occur) is critical to improving the CPUE standardization procedure intropical tuna purse seine fisheries.
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Langue eng Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0165-7836 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 335
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Auteur Travis, J.; Coleman, F.C.; Auster, P.J.; Cury, P.; Estes, J.A.; Orensanz, J.; Peterson, C.H.; Power, M.E.; Steneck, R.S.; Wootton, J.T.
Titre Integrating the invisible fabric of nature into fisheries management Type (down) Article scientifique
Année 2014 Publication Revue Abrégée Proceedings of the National Academy of Sciences of the United States of America
Volume 111 Numéro 2 Pages 581-584
Mots-Clés alternative states; ecosystem flips; fisheries collapse; ocean fisheries
Résumé Overfishing and environmental change have triggered many severe and unexpected consequences. As existing communities have collapsed, new ones have become established, fundamentally transforming ecosystems to those that are often less productive for fisheries, more prone to cycles of booms and busts, and thus less manageable. We contend that the failure of fisheries science and management to anticipate these transformations results from a lack of appreciation for the nature, strength, complexity, and outcome of species interactions. Ecologists have come to understand that networks of interacting species exhibit nonlinear dynamics and feedback loops that can produce sudden and unexpected shifts. We argue that fisheries science and management must follow this lead by developing a sharper focus on species interactions and how disrupting these interactions can push ecosystems in which fisheries are embedded past their tipping points.
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ISSN 0027-8424 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 336
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Auteur Tremblay, Y.; Thiebault, A.; Mullers, R.; Pistorius, P.
Titre Bird-borne video-cameras show that seabird movement patterns relate to previously unrevealed proximate environment, not prey Type (down) Article scientifique
Année 2014 Publication Revue Abrégée Plos One
Volume 9 Numéro 2 Pages
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Résumé The study of ecological and behavioral processes has been revolutionized in the last two decades with the rapid development of biologging-science. Recently, using image-capturing devices, some pilot studies demonstrated the potential of understanding marine vertebrate movement patterns in relation to their proximate, as opposed to remote sensed environmental contexts. Here, using miniaturized video cameras and GPS tracking recorders simultaneously, we show for the first time that information on the immediate visual surroundings of a foraging seabird, the Cape gannet, is fundamental in understanding the origins of its movement patterns. We found that movement patterns were related to specific stimuli which were mostly other predators such as gannets, dolphins or fishing boats. Contrary to a widely accepted idea, our data suggest that foraging seabirds are not directly looking for prey. Instead, they search for indicators of the presence of prey, the latter being targeted at the very last moment and at a very small scale. We demonstrate that movement patterns of foraging seabirds can be heavily driven by processes unobservable with conventional methodology. Except perhaps for large scale processes, local-enhancement seems to be the only ruling mechanism; this has profounds implications for ecosystem-based management of marine areas.
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ISSN 1932-6203 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 337
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