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Auteur Garavelli, L.; Kaplan, D.; Colas, F.; Stotz, W.; Yannicelli, B.; Lett, C. url  doi
openurl 
  Titre Identifying appropriate spatial scales for marine conservation and management using a larval dispersal model : the case of Concholepas concholepas (loco) in Chile Type Article scientifique
  Année 2014 Publication Revue Abrégée Progress in Oceanography  
  Volume 124 Numéro Pages 42-53  
  Mots-Clés  
  Résumé Along the coast of Chile, fisheries targeting the marine gastropod Concholepas concholepas, commonly named “loco”, were highly valuable until the end of the 80s when catches declined significantly. Since the late 90s, a management plan based on territorial-user-rights areas has been implemented, with limited effect on stock recovery. More effective loco conservation and management is impeded by lack of information regarding connectivity via larval dispersal between these individually-managed areas. To develop a regional view of loco connectivity, we integrate loco life history information into a biophysical, individual-based larval dispersal model. This model is used to evaluate scales of loco connectivity and seasonality in connectivity patterns, as well as to partition the coast into largely disconnected subpopulations using a recently developed connectivity-matrix clustering algorithm. We find mean dispersal distances ranging from 170 to 220 km depending on release depth of larvae and planktonic larval duration. Settlement success levels depend quantitatively on the physical and biological processes included in the model, but connectivity patterns remain qualitatively similar. Model estimates of settlement success peak for larval release dates in late austral autumn, consistent with field results and with favorable conditions for larval coastal retention due to weak upwelling during austral autumn. Despite the relatively homogeneous Chilean coastline, distinct subpopulations with minimal connectivity between them are readily identifiable. Barriers to connectivity that are robust to changes in model configuration exist at 23 degrees S and 29 degrees S latitudes. These zones are all associated with important headlands and embayments of the Chilean coast.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection (down) Numéro de collection Edition  
  ISSN 0079-6611 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 359  
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Auteur HANEL, R.; STEPPUTTIS, D.; BONHOMMEAU, S.; CASTONGUAY, M.; SCHABER, M.; WYSUJACK, K.; VOBACH, M.; MILLER, M.J. url  openurl
  Titre Low larval abundance in the Sargasso Sea: new evidence about reduced recruitment of the Atlantic eels Type Article scientifique
  Année 2014 Publication Revue Abrégée Naturwissenschaften  
  Volume 101 Numéro 12 Pages 1041-1054  
  Mots-Clés Anguillidae; Anguilliformes; Eel larvae; Population declines; spawning area  
  Résumé The European eel Anguilla anguilla has shown decreased recruitment in recent decades. Despite increasing efforts to establish species recovery measures, it is unclear if the decline was caused by reduced numbers of reproductive-stage silver eels reaching the spawning area, low early larval survival, or increased larval mortality during migration to recruitment areas. To determine if larval abundances in the spawning area significantly changed over the past three decades, a plankton trawl sampling survey for anguillid leptocephali was conducted in March and April 2011 in the spawning area of the European eel that was designed to directly compare to collections made in the same way in 1983 and 1985. The catch rates of most anguilliform leptocephali were lower in 2011, possibly because of the slightly smaller plankton trawl used, but the relative abundances of European eel and American eel, Anguilla rostrata, leptocephali were much lower in 2011 than in 1983 and 1985 when compared to catches of other common leptocephali. The leptocephali assemblage was the same in 2011 as in previous years, but small larvae of mesopelagic snipe eels, Nemichthys scolopaceus, which spawn sympatrically with anguillid eels, were less abundant. Temperature fronts in the spawning area were also poorly defined compared to previous years. Although the causes for low anguillid larval abundances in 2011 are unclear, the fact that there are presently fewer European and American eel larvae in the spawning area than during previous time periods indicates that decreased larval abundance and lower eventual recruitment begin within the spawning area.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection (down) Numéro de collection Edition  
  ISSN 0028-1042 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1127  
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Auteur Grande, M.; Murua, H.; Zudaire, I.; Goni, N.; Bodin, N. url  doi
openurl 
  Titre Reproductive timing and reproductive capacity of the Skipjack Tuna (Katsuwonus pelamis) in the western Indian Ocean Type Article scientifique
  Année 2014 Publication Revue Abrégée Fisheries Research  
  Volume 156 Numéro Pages 14-22  
  Mots-Clés Condition; Gonadosomatic index; Oocyte; Reproductive capacity; Spawning season  
  Résumé We studied the sexual maturity, batch fecundity and spawning season of the Skipjack Tuna Katsuwonus pelamis. Generalized additive modelling was applied to assess the effect of demographic features on ovary growth. During 2009 and 2010, 673 females were caught on board a purse-seine fishing vessel in the western Indian Ocean. Fish were classified into different reproductive phases and this information was used to determine the size at maturity (L-50), the timing of spawning and the batch fecundity (n = 51). The size at maturity (L-50) for females was estimated to be 39.9 cm. The mean relative batch fecundity was 140 +/- 64 eggs g(-1) of fish. Spawning occurs during the monsoons and inter-monsoon seasons with peaks in the reproductive activity during the North-east and South-west monsoon events. Demographic differences were detected in the reproductive timing of the population and a large investment in gamete production was observed in fish with high hepatic condition and in their first spawning year.  
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  Langue Langue du Résumé Titre Original  
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  Volume de collection (down) Numéro de collection Edition  
  ISSN 0165-7836 ISBN Médium  
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  Numéro d'Appel LL @ pixluser @ collection 360  
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Auteur LE MAHO, Y.; WHITTINGTON, J.D.; HANUISE, N.; PEREIRA, L.; BOUREAU, M.; BRUCKER, M.; CHATELAIN, N.; COURTECUISSE, J.; CRENNER, F.; FRIESS, B.; GROSBELLET, E.; KERNALEGUEN, L.; OLIVER, F.; SARAUX, C.; VETTER, N.; VIBLANC, V.A.; THIERRY, B.; TREMBLAY, P.; GROSCOLAS, R.; LE BOHEC, C. url  openurl
  Titre Rovers minimize human disturbance in research on wild animals Type Article scientifique
  Année 2014 Publication Revue Abrégée Nature Methods  
  Volume 11 Numéro 12 Pages 1242-1244  
  Mots-Clés  
  Résumé Investigating wild animals while minimizing human disturbance remains an important methodological challenge. When approached by a remote-operated vehicle (rover) which can be equipped to make radio-frequency identifications, wild penguins had significantly lower and shorter stress responses (determined by heart rate and behavior) than when approached by humans. Upon immobilization, the rover-unlike humans-did not disorganize colony structure, and stress rapidly ceased. Thus, rovers can reduce human disturbance of wild animals and the resulting scientific bias.  
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  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection (down) Numéro de collection Edition  
  ISSN 1548-7091 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1128  
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Auteur Hancke, L.; Roberts, M.J.; Ternon, J.-F. url  doi
openurl 
  Titre Surface drifter trajectories highlight flow pathways in the Mozambique Channel Type Article scientifique
  Année 2014 Publication Revue Abrégée Deep-Sea Research Part II.Topical Studies in Oceanography  
  Volume 100 Numéro No spécial Pages 27-37  
  Mots-Clés Frontal flow; Mesoscale eddies; Mozambique Channel; Surface circulation; Surface drifters  
  Résumé The pattern of surface circulation in the Mozambique Channel was elucidated from the trajectories of 82 satellite-tracked drifters over the period 2000-2010 and complementary satellite-derived altimetry. Overall, the trajectories indicated that anticyclonic activity was mostly observed on the western side of the Channel, with cyclonic activity being more prevalent in the east. A lack of eddy activity was noted in the southeast corner of the Channel (i.e. SW of Madagascar). Drifter behaviour illustrated that surface water from the Comoros Basin, entrained into anticyclonic eddies during formation, can be retained and isolated for months whilst being transported southwards through the Channel. During a tropical cyclone weather event, a drifter was observed to switch between counter-rotating eddies indicating that horizontal mixing of the Ekman layer does occur. The drifters also illustrated and emphasised the flow field and transport between eddies (i.e. the interstitial flow) in the Mozambique Channel. Despite the dominance of southward propagating anticyclones, drifters were able to move north and south through the Channel in the frontal flow field between eddies within periods of 51-207 days. Cross-channel transport in both directions between the Madagascan and Mozambique shelf regions was similarly observed, with time spans of 19-30 days. Surprisingly, drifters from the southern limb of the East Madagascar Current were transported westward across the channel to the Mozambique shelf. This transport was similarly facilitated by the frontal flow field between eddies. It is hypothesised that the frontal zones between eddies and interstitial waters play an important role in distributing biota in the Mozambique Channel.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur Barlow, R.; Marsac, F.; Ternon, J.-F.; Roberts, M.  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection (down) Numéro de collection Edition  
  ISSN 0967-0645 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 361  
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