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Auteur Andrello, M.; Mouillot, D.; Somot, S.; Thuiller, W.; Manel, S.
Titre Additive effects of climate change on connectivity between marine protected areas and larval supply to fished areas Type Article scientifique
Année 2015 Publication Revue Abrégée Diversity Distrib.
Volume 21 Numéro 2 Pages 139-150
Mots-Clés Biophysical model; conservation planning; Epinephelus marginatus; larval dispersal; larval growth rate; reproductive timing
Résumé Aim To study the combined effects of climate change on connectivity between marine protected areas (MPAs) and larval supply to the continental shelf. Location The Mediterranean Sea, where sea surface temperatures are expected to strongly increase by the end of the 21st century, represents an archetypal situation with a dense MPA network but resource overexploitation outside. Methods Using an individual-based mechanistic model of larval transport, forced with an emission-driven regional climate change scenario for the Mediterranean Sea, we explored the combined effects of changes in hydrodynamics, adult reproductive timing and larval dispersal on the connectivity among MPAs and their ability to seed fished areas with larvae. Results We show that, over the period 1970–2099, larval dispersal distances would decrease by 10%, the continental shelf area seeded with larvae would decrease by 3% and the larval retention fraction would increase by 5%, resulting in higher concentration of larvae in smaller areas of the continental shelf. However, connectance within the MPA network would increase by 5% as more northern MPAs would become suitable for reproduction with increasing temperatures. We also show that the effects of changes in adult reproductive timing and larval dispersal on connectivity patterns are additive. Main conclusions Climate change will influence connectivity and the effectiveness of MPA networks, and should receive more attention in future conservation planning and large-scale population dynamics.
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ISSN 1472-4642 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1282
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Auteur Bauer, R.K.; Stepputtis, D.; Gräwe, U.; Zimmermann, C.; Hammer, C.
Titre Wind-induced variability in coastal larval retention areas: a case study on Western Baltic spring-spawning herring Type Article scientifique
Année 2013 Publication Revue Abrégée Fisheries Oceanography
Volume Numéro Pages
Mots-Clés atmospheric forcing; Baltic Sea; biophysical modelling; Greifswalder Bodden; herring; larval retention; recruitment; spring spawners
Résumé The investigation of larval dispersal and retention, their variability and dependence on wind conditions, has become a major topic in fisheries research owing to potential effects on stock recruitment and stock structuring. The present study quantifies the wind-induced variability of larval retention of herring in a highly productive coastal lagoon of the Western Baltic Sea. This lagoon, the Greifswalder Bodden, represents the main spawning area of Western Baltic Spring-Spawning Herring, a stock that has recently undergone a continuous decline in recruitment. The study tests whether this decline was related to changes in larval retention, more precisely to changes in wind conditions, the main forcing of the lagoon's circulation. To answer this, a model approach was applied. Larvae were tracked as Lagrangian drifters under constant and variable wind conditions, examining the main drift patterns and reconstructing the incidents during the period of recruitment decline. For the latter, weekly cohorts of virtual larvae were released in the lagoon over the entire spawning period (April–June; \textgreater16 weeks). The fraction of retained larvae per cohort was related to observed larval abundances. On this basis, a new retention index was defined to evaluate the annual larval retention. The results presented cannot explain the observed recruitment decline but characterize the lagoon as an important larval retention area by virtue of unsteady wind conditions that prevent a steady outflow of larvae.
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ISSN 1365-2419 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 255
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Auteur Crochelet, E.; Barrier, N.; Andrello, M.; Marsac, F.; Spadone, A.; Lett, C.
Titre Connectivity between seamounts and coastal ecosystems in the Southwestern Indian Ocean Type Article scientifique
Année 2020 Publication Revue Abrégée Deep-Sea Res. Part II-Top. Stud. Oceanogr.
Volume 176 Numéro Pages 104774
Mots-Clés behavior; Biophysical model; Connectivity; conservation; coral-reef fishes; Ichthyop; Lagrangian modelling; larvae dispersal; Larval drift; Larval duration; local retention; madagascar; marine populations; model; population connectivity; recruitment; Seamounts; Southwestern indian ocean; Surface drifters
Résumé Understanding larval connectivity patterns is critical for marine spatial planning, particularly for designing marine protected areas and managing fisheries. Patterns of larval dispersal and connectivity can be inferred from numerical transport models at large spatial and temporal scales. We assess model-based connectivity patterns between seamounts of the Southwestern Indian Ocean (SWIO) and the coastal ecosystems of Mauritius, La Reunion, Madagascar, Mozambique and South Africa, with emphasis on three shallow seamounts (La Pemuse [LP], MAD-Ridge [MR] and Walters Shoal [WS]). Using drifter trajectory and a Lagrangian model of ichthyo-plankton dispersal, we show that larvae can undertake very long dispersion, with larval distances increasing with pelagic larval duration (PLD). There are three groups of greater connectivity: the region between the eastern coast of Madagascar, Mauritius and La Reunion islands; the seamounts of the South West Indian Ridge; and the pair formed by WS and a nearby un-named seamount. Connectivity between these three groups is evident only for the longest PLD examined (360 d). Connectivity from seamounts to coastal ecosystems is weak, with a maximum of 2% of larvae originating from seamounts reaching coastal ecosystems. Local retention at the three focal seamounts (LP, MR and WS) peaks at about 11% for the shortest PLD considered (15 d) at the most retentive seamount (WS) and decreases sharply with increasing PLD. Information on PLD and age of larvae collected at MR and LP are used to assess their putative origin. These larvae are likely self-recruits but it is also plausible that they immigrate from nearby coastal sites, i.e. the southern coast of Madagascar for MR and the islands of La Reunion and Mauritius for LP.
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ISSN 0967-0645 ISBN Médium
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Notes WOS:000556810400003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2840
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Auteur Cuif, M.; Kaplan, D.M.; Lefèvre, J.; Faure, V.M.; Caillaud, M.; Verley, P.; Vigliola, L.; Lett, C.
Titre Wind-induced variability in larval retention in a coral reef system: a biophysical modelling study in the South-West Lagoon of New Caledonia Type Article scientifique
Année 2014 Publication Revue Abrégée Progress in Oceanography
Volume 122 Numéro Pages 105-115
Mots-Clés Biophysical model; Dascyllus aruanus; Homing; Larval dispersal; New Caledonia; Precompetency; Wind-driven transport
Résumé In the present work, a biophysical dispersal model is used to understand the role of the physical environment in determining reef fish larval dispersal patterns in the South-West Lagoon of New Caledonia. We focus on a reef fish species, the humbug damselfish Dascyllus aruanus, to investigate seasonal variability of simulated larval retention at the scale of a reef patch and at the scale of the lagoon, and to explore links between larval retention and wind variability. The model shows that retention exhibits considerable temporal variability and periodically reaches values much larger than anticipated. Non-zero larval settlement occurs over a large part of the lagoon. Nevertheless, settlement values decrease quickly away from the natal reef and mean dispersal distances are of order 25-35 km. Cross-correlation analyses indicate that weather conditions characterized by strong south east trade winds lead to low retention rates at both local (reef) and regional (lagoon) scales. By contrast, subtropical weather conditions characterized by weak winds result in high retention rates. These results suggest that large-scale weather regimes can be used as proxies for larval retention of the humbug damselfish in the South-West Lagoon of New Caledonia. Nevertheless, relatively small mean dispersal distances suggest that meta-population dynamics occur on relatively small spatial scales.
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ISSN 0079-6611 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 318
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Auteur Lett, C.; Barrier, N.; Bahlali, M.
Titre Converging approaches for modeling the dispersal of propagules in air and sea Type Article scientifique
Année 2020 Publication Revue Abrégée Ecol. Model.
Volume 415 Numéro Pages 108858
Mots-Clés Aerial dispersal; Aquatic dispersal; Atmospheric dispersal; Biophysical model; Eulerian model; Lagrangian model; larval dispersal; long-distance dispersal; Marine dispersal; Oceanic dispersal; particle trajectories; population connectivity; Propagule dispersal; reef fish; schooling behavior; seed dispersal; spatially explicit; terrestrial ecology; understanding recruitment; Wind dispersal
Résumé Terrestrial plants seeds, spores and pollen are often dispersed by wind. Likewise, most eggs and larvae of marine organisms are dispersed by oceanic currents. It was historically believed that the spatial scale at which dispersal occurs was orders of magnitude smaller for plants than for fish. However, recent empirical estimates of seed and larval dispersal suggest that these dispersal scales are more alike than previously thought. The modeling approaches used to simulate aerial and aquatic dispersal are also converging. Similar biophysical models are developed, in which outputs of Eulerian models simulating the main physical forcing mechanism (wind or currents) are used as inputs to Lagrangian models that include biological components (such as seed terminal velocity or larval vertical migration). These biophysical models are then used to simulate trajectories of the biological entities (seeds, larvae) in three dimensions. We reflect on these converging trends by first putting them into an historical perspective, and then by comparing the physical and biological processes represented in marine larva vs. terrestrial seed dispersal models, the data used for the models output corroboration, and the tools available to perform simulations. We conclude that this convergence offers the opportunity to bridge the gap between two scientific communities which are currently largely disconnected. More broadly, we also see our comparison across systems as a useful way to strengthen the links between aquatic and terrestrial ecology by sharing knowledge, methods, tools, and concepts.
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Langue English 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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Notes WOS:000501415400006 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2706
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