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Auteur (up) Cox, S.L.; Embling, C.B.; Hosegood, P.J.; Votier, S.C.; Ingram, S.N.
Titre Oceanographic drivers of marine mammal and seabird habitat-use across shelf-seas: A guide to key features and recommendations for future research and conservation management Type Article scientifique
Année 2018 Publication Revue Abrégée Estuar. Coast. Shelf Sci.
Volume 212 Numéro Pages 294-310
Mots-Clés Bio-physical coupling; bottle-nosed dolphins; california current system; coastal upwelling system; Conservation management; ecosystem-based management; Foraging ecology; Habitat selection; Marine mammals; Oceanography; porpoise phocoena-phocoena; predator-prey interactions; Seabirds; southeastern bering-sea; st-george island; thin zooplankton layers; tidal-stream environments
Résumé Mid-latitude (similar to 30-60 degrees) seasonally stratifying shelf-seas support a high abundance and diversity of marine predators such as marine mammals and seabirds. However, anthropogenic activities and climate change impacts are driving changes in the distributions and population dynamics of these animals, with negative consequences for ecosystem functioning. Across mid-latitude shelf-seas marine mammals and seabirds are known to forage across a number of oceanographic habitats that structure the spatio-temporal distributions of prey fields. Knowledge of these and the bio-physical mechanisms driving such associations are needed to improve marine management and policy. Here, we provide a concise and easily accessible guide for both researchers and managers of marine systems on the predominant oceanographic habitats that are favoured for foraging by marine mammals and seabirds across mid-latitude shelf-seas. We (1) identify and describe key discrete physical features present across the continental shelf, working inshore from the shelf-edge to the shore line, (2) provide an overview of findings relating to associations between these habitats and marine mammals and seabirds, (3) identify areas for future research and (4) discuss the relevance of such information to conservation management. We show that oceanographic features preferentially foraged at by marine mammals and seabirds include shelf edge fronts, upwelling and tidal-mixing fronts, offshore banks and internal waves, regions of stratification, and topographically complex coastal areas subject to strong tidal flow. Whilst associations were variable across taxa and through space and time, in the majority of cases interactions between bathymetry and tidal currents appear to play a dominant role, alongside patterns in seasonal stratification and shelf-edge upwelling. We suggest that the ecological significance of these bio-physical structures stems from a capacity to alter the densities, distributions (both horizontally and vertically) and/or behaviours of prey in a persistent and/or predictable manner that increases accessibility for predators, and likely enhances foraging efficiency. Future conservation management should aim to preserve and protect these habitats. This will require adaptive and holistic strategies that are specifically tailored to the characteristics of an oceanographic feature, and where necessary, evolve through space and time in response to spatio-temporal variability. Improved monitoring of animal movements and biophysical conditions across shelf-seas would aid in this. Areas for future research include multi-disciplinary/ trophic studies of the mechanisms linking bio-physical processes, prey and marine mammals and seabirds (which may elucidate the importance of lesser studied features such as bottom fronts and Langmuir circulation cells), alongside a better understanding of how predators perceive their environment and develop foraging strategies during immature/juvenile stages. Estimates of the importance of oceanographic habitat features at a population level should also be obtained. Such information is vital to ensuring the future health of these complex ecosystems, and can be used to assess how anthropogenic activities and future environmental changes will impact the functioning and spatio-temporal dynamics of these bio-physical features and their use by marine predators.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0272-7714 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2428
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Auteur (up) Dupuy, C.; Pagano, M.; Got, P.; Domaizon, I.; Chappuis, A.; Marchessaux, G.; Bouvy, M.
Titre Trophic relationships between metazooplankton communities and their plankton food sources in the Iles Eparses (Western Indian Ocean) Type Article scientifique
Année 2016 Publication Revue Abrégée Marine Environmental Research
Volume 116 Numéro Pages 18-31
Mots-Clés feeding ecology; grazing effect; Iles Eparses; Mayotte; Metazooplankton; spatial distribution
Résumé Coral reef and atoll lagoons are among the most diversified marine ecosystems but also the most affected by the combined effects of climate change and human activities. The Iles Eparses (Scattered Islands) in the Western Indian Ocean have been little affected by human pressure and can be considered to be “pristine” ecosystems. Metazooplankton plays a major role in the functioning and productivity of aquatic ecosystems, and this study was undertaken: (i) to determine the spatial abundance, distribution and species composition of metazooplankton, (ii) to assess the effect of metazooplankton grazing on pico- and nanophytoplankton and (iii) to analyze the trophic positions of metazooplankton by using the stable isotope signatures of a wide variety of taxa and particulate organic matter from the Iles Eparses and Mayotte. Tromelin Island (which is not located in the Mozambique Channel) had the lowest metazooplankton abundance with no cyanobacteria Trichodesmium spp. or mollusks (pteropods) presence, and with δ15N signatures of organisms that were higher than for the islands in the Mozambique Channel. Trichodesmium spp. was found in the Mozambique Channel and the plankton food web was probably based preferentially on these cyanobacteria with lower δ15N signatures indicating direct or indirect trophic transfer of diazotrophic nitrogen to metazooplankton. Three of the islands were distinct: Europa had the highest proportion of copepods, with oithonids being dominant, which is typical of rich mangrove systems, while Juan de Nova and Mayotte seemed to be the sites most affected by human activity with a high abundance of appendicularians and distinct particulate organic matter ∂13C signatures. Grazing experiments showed that food could be a limiting factor for metazooplankton in the Iles Eparses. However, the effect of metazooplankton grazing on phytoplankton appeared to be very low (0.01–2.32% of the total phytoplankton per day).
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ISSN 0141-1136 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1496
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Auteur (up) Gueroun, S.K.M.; Molinero, J.C.; Piraino, S.; Daly Yahia, M.N.
Titre Population dynamics and predatory impact of the alien jellyfish Aurelia solida (Cnidaria, Scyphozoa) in the Bizerte Lagoon (southwestern Mediterranean Sea) Type Article scientifique
Année 2020 Publication Revue Abrégée Mediterr. Mar. Sci.
Volume 21 Numéro 1 Pages 22-35
Mots-Clés abundance; asexual reproduction rates; aurita cnidaria; common jellyfish; cyanea-capillata; gullmar fjord; mesozooplankton; moon jellyfish; predation; prey selection; prince-william-sound; Scyphomedusae; SW Mediterranean; tokyo bay; zooplankton
Résumé Understanding the life cycle strategies and predatory impact of alien jellyfish species is critical to mitigate the impact that these organisms may have on local populations, biodiversity, and ultimately on the functioning of food webs. In the Mediterranean Sea, little is known about the dynamics of alien jellyfish, despite this biodiversity hotspot being one of the most threatened areas by increasing numbers of alien jellyfish. Here, we investigated the population dynamics and predatory impact of a non-indigenous scyphomedusa, Aurelia solida Browne 1905, in the Bizerte Lagoon, Tunisia. The study was based on bimonthly surveys performed over two consecutive years, from November 2012 to August 2014. Field observations showed that the planktonic phase of A. solida occurs from winter to early summer. Prey composition was investigated by means of gut content and field zooplankton analyses. Calanoid copepods, mollusc larvae, and larvaceans represented the main food items of A. solida. To determine the jellyfish feeding rate and their predatory impact on zooplankton populations, the digestion time for zooplankton prey was assessed at three different temperatures: 13, 18, and 23 degrees C in laboratory conditions, corresponding to the average range of temperatures encountered by A. solida in the Bizerte Lagoon. We found that A. solida consumed 0.5-22.5% and 0.02-37.3% of the daily zooplankton standing stock in 2013 and 2014, respectively. These results indicate a non-negligible but restricted seasonal grazing impact on some mesozooplankton groups, explained by the relatively short lifespan of the medusa stage (5-6 months).
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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 1108-393x ISBN Médium
Région Expédition Conférence
Notes WOS:000524248700003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2773
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Auteur (up) Jaspers, C.; Huwer, B.; Antajan, E.; Hosia, A.; Hinrichsen, H.-H.; Biastoch, A.; Angel, D.; Asmus, R.; Augustin, C.; Bagheri, S.; Beggs, S.E.; Balsby, T.J.S.; Boersma, M.; Bonnet, D.; Christensen, J.T.; Daenhardt, A.; Delpy, F.; Falkenhaug, T.; Finenko, G.; Fleming, N.E.C.; Fuentes, V.; Galil, B.; Gittenberger, A.; Griffin, D.C.; Haslob, H.; Javidpour, J.; Kamburska, L.; Kube, S.; Langenberg, V.T.; Lehtiniemi, M.; Lombard, F.; Malzahn, A.; Marambio, M.; Mihneva, V.; Moller, L.F.; Niermann, U.; Okyar, M.I.; Ozdemir, Z.B.; Pitois, S.; Reusch, T.B.H.; Robbens, J.; Stefanova, K.; Thibault, D.; van der Veer, H.W.; Vansteenbrugge, L.; van Walraven, L.; Wozniczka, A.
Titre Ocean current connectivity propelling the secondary spread of a marine invasive comb jelly across western Eurasia Type Article scientifique
Année 2018 Publication Revue Abrégée Glob. Ecol. Biogeogr.
Volume 27 Numéro 7 Pages 814-827
Mots-Clés abundance; biodiversity; biological invasions; black-sea; caspian sea; consequences; ctenophore mnemiopsis-leidyi; gelatinous zooplankton; invasion corridors; invasive species; jellyfish; larval transport; marine connectivity; Mnemiopsis leidyi; north-sea; range expansion; source populations; source-sink dynamics; waters; zooplankton
Résumé Aim: Invasive species are of increasing global concern. Nevertheless, the mechanisms driving further distribution after the initial establishment of non-native species remain largely unresolved, especially in marine systems. Ocean currents can be a major driver governing range occupancy, but this has not been accounted for in most invasion ecology studies so far. We investigate how well initial establishment areas are interconnected to later occupancy regions to test for the potential role of ocean currents driving secondary spread dynamics in order to infer invasion corridors and the source-sink dynamics of a non-native holoplanktonic biological probe species on a continental scale. Location: Western Eurasia. Time period: 1980s-2016. Major taxa studied: 'Comb jelly' Mnemiopsis leidyi. Methods: Based on 12,400 geo-referenced occurrence data, we reconstruct the invasion history of M. leidyi in western Eurasia. We model ocean currents and calculate their stability to match the temporal and spatial spread dynamics with large-scale connectivity patterns via ocean currents. Additionally, genetic markers are used to test the predicted connectivity between subpopulations. Results: Ocean currents can explain secondary spread dynamics, matching observed range expansions and the timing of first occurrence of our holoplanktonic non-native biological probe species, leading to invasion corridors in western Eurasia. In northern Europe, regional extinctions after cold winters were followed by rapid recolonizations at a speed of up to 2,000 km per season. Source areas hosting year-round populations in highly interconnected regions can re-seed genotypes over large distances after local extinctions. Main conclusions: Although the release of ballast water from container ships may contribute to the dispersal of non-native species, our results highlight the importance of ocean currents driving secondary spread dynamics. Highly interconnected areas hosting invasive species are crucial for secondary spread dynamics on a continental scale. Invasion risk assessments should consider large-scale connectivity patterns and the potential source regions of non-native marine species.
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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 1466-822x ISBN Médium
Région Expédition Conférence
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Numéro d'Appel MARBEC @ alain.herve @ collection 2390
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Auteur (up) Lezama-Ochoa, A.; Grados, D.; Lebourges Dhaussy, A.; Irigoien, X.; Chaigneau, A.; Bertrand, A.
Titre Biological characteristics of the hydrological landscapes in the Bay of Biscay in spring 2009 Type Article scientifique
Année 2015 Publication Revue Abrégée Fisheries Oceanography
Volume 24 Numéro 1 Pages 26-41
Mots-Clés acoustics; Bay of Biscay; Biogeography; fish; horizontal distribution; hydrological structures; macrozooplankton; patterns
Résumé In the present study we investigated the biogeography of macrozooplankton and fish biomass in the Bay of Biscay. In this region, we defined six different landscapes based on the hydrogeographical characteristics observed in spring 2009. We then related landscape's characteristics and environmental parameters such as light attenuation depth and chlorophyll-a with macrozooplankton and fish acoustic biomass. Hydrodynamic structures together with coastal influences (river discharges, predation pressure and depth preference) and vertical thermohaline structure/mixing (feeding modes and ability to stay in preferred layers) appeared as the main factors determining the biological distribution. Besides, variance partitioning was used to assess the respective roles played by the hydrological environment, the geographical space and the biological environment alone, and their interactions. Results revealed that: (i) macrozooplankton and fish have a preference for different hydrogeographical landscapes; (ii) the association between hydrological conditions and geographical features, i.e. the spatial structure of the hydrological environment, plays a key role in the distribution of macrozooplankton; and (iii) prey-predator relationships have to be taken into account to provide a comprehensive characterization of habitat suitability.
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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 1054-6006 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1109
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