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Auteur (down) Zupa, R.; Fauvel, C.; Mylonas, C.C.; Pousis, C.; Santamaria, N.; Papadaki, M.; Fakriadis, I.; Cicirelli, V.; Mangano, S.; Passantino, L.; Lacalandra, G.M.; Corriero, A.
Titre Rearing in captivity affects spermatogenesis and sperm quality in greater amberjack, Seriola dumerili (Risso, 1810) Type Article scientifique
Année 2017 Publication Revue Abrégée J. Anim. Sci.
Volume 95 Numéro 9 Pages 4085-4100
Mots-Clés acute stress; apoptosis; atlantic bluefin tuna; cultured fish; germ cell apoptosis; germ cell proliferation; germ-cell proliferation; greater amberjack; Marine fish; Motility; ovarian-steroid production; rearing in captivity; reproductive-biology; Seriola dumerili; Sperm quality; thunnus-thynnus l.
Résumé The greater amberjack, Seriola dumerili (Risso, 1810), is a promising candidate for the diversification of European aquaculture production, but inconsistent reproduction in captivity prevents commercial production. Recent studies showed that greater amberjack confined in sea cages exhibited scarce gonad development and early interruption of gametogenic activity during the reproductive season. The aim of the present study was to improve our understanding of the observed impairment of spermatogenesis. Adult wild and captive-reared males were sampled during 3 different phases of the reproductive cycle: early gametogenesis (EARLY; late April to early May), advanced gametogenesis (ADVANCED; late May to early June), and spawning (SPAWNING; late June to July). Spermatogonial stem cells and proliferating germ cells were identified through the immunohistochemical localization of Pou5f1 and proliferating cell nuclear antigen, respectively. Apoptotic germ cells were identified throughout the terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling method. Sperm quality of captive-reared fish was evaluated using computer-assisted sperm analysis. Captive-reared males exhibited seminiferous lobules of a smaller diameter, a precocious and progressive decrease of spermatogonial mitosis, and a high level of apoptosis at the beginning of the reproductive season, concomitant with a many-fold higher 17 beta-estradiol plasma concentration. The motile spermatozoa percentage of captive greater amberjack was lower than in other teleosts, and a drastic decrease of spermatozoa motility duration, velocity, and ATP content occurred along the reproductive season. An abnormal increase of sperm concentration as well as an increase of dead spermatozoa occurred during the SPAWNING phase, probably because of lack of sperm hydration and ejaculation and consequent sperm ageing. The present study demonstrates the extreme susceptibility of greater amberjack to rearing stress and underscores the need for improvement of the rearing and handling procedures to ameliorate gametogenesis dysfunctions in commercial aquaculture production.
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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 0021-8812 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2210
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Auteur (down) Vieira de Assuncao, R.; Silva, A.C.; Roy, A.; Bourles, B.; Silva, C.H.S.; Ternon, J.-F.; Araujo, M.; Bertrand, A.
Titre 3D characterisation of the thermohaline structure in the southwestern tropical Atlantic derived from functional data analysis of in situ profiles Type Article scientifique
Année 2020 Publication Revue Abrégée Prog. Oceanogr.
Volume 187 Numéro Pages 102399
Mots-Clés barrier layers; Barrier layer; decadal changes; Mixed layer; mixed-layer; North Brazilian Undercurrent system; ocean; Ocean stratification; salinity; seasonal-variations; south-atlantic; thermocline; Thermocline; water masses; western boundary circulation; Western boundary current
Résumé The dynamic of the thermohaline structure of the upper ocean, which depends on ocean-atmosphere interactions, drives most near surface oceanic processes, including the control of gases and heat fluxes, and nutrient availability in the photic layer. The thermohaline structure of the southwestern tropical Atlantic (SWTA), a key region for diagnosing variation of the Atlantic Meridional Overturning Circulation, has prime impact on global climate. Characterising the thermohaline structure is typically based on the application of classical statistical methods on vertical profiles. Such approach has important limitations since classical methods do not explicitly contemplate the vertical nature of the profiles. Functional Data Analysis (FDA) is a new alternative to solve such drawbacks. Here, we apply an FDA approach to characterise the 3D canonical thermohaline structure of the SWTA in austral spring and fall. Our results reveal a clear spatial pattern with the presence of three areas with significantly different thermohaline structure. Area 1, mostly located along the continental slope, reflects the western boundary current system, with low static stability and high frequency of occurrence of barrier layer (BL). Conversely, Area 2, located along the Fernando de Noronha chain, presents strong static stability with a well-marked thermocline. This area, under the influence of the eastern Atlantic, is characterised by a low BL frequency, which is seasonally modulated by the latitudinal oscillation of the Intertropical Convergence Zone, controlling the regime of precipitation. In turn, Area 3 behaves as a transition zone between A1 and A2 with the presence of the water core of maximum salinity in subsurface, and therefore presence of strong-moderate BL. Beyond this study, FDA approach emerges as a powerful way to describe, characterise, classify and compare ocean patterns and processes. It can be applied to in situ data but could also be used to deeply and comprehensively explore ocean model output.
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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 0079-6611 ISBN Médium
Région Expédition Conférence
Notes WOS:000572347900003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2897
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Auteur (down) Van Beveren, E.; Fromentin, J.-M.; Rouyer, T.; Bonhommeau, S.; Brosset, P.; Saraux, C.
Titre The fisheries history of small pelagics in the Northern Mediterranean Type Article scientifique
Année 2016 Publication Revue Abrégée ICES J. Mar. Sci.
Volume 73 Numéro 6 Pages 1474-1484
Mots-Clés age; anchovy; atlantic; dynamics; fish; fish landings; fluctuations; Gulf of Lions; historical time series; landings; mackerel; multidecadal oscillation; populations; Sardine; variability
Résumé Since 2007, the biomass of sardine and anchovy in the NW Mediterranean has remained persistently low, whereas the biomass of the commercially low-valued sprat has exploded. Also, simultaneous decreases in condition, size, and/or age of these populations were observed. Altogether, this resulted in a drop in landings of small pelagics. To understand the amplitude of these events and to provide a baseline scenario against which current changes can be compared, we compiled exceptionally long landing series (1865-2013) of sardine, anchovy, and mackerel for different subregions of the southern French coast. We characterized the fluctuations of these landings and compared these with environmental drivers (sea surface temperature, Rhone river discharge, North Atlantic Oscillation, Western Mediterranean Oscillation-WeMO, and Atlantic Multidecadal Oscillation-AMO), using different time-series analyses. We also collated historical data to infer qualitative changes in fishing effort over time. A fishing effort related increase in landings was observed around 1962 for all three species, although current sardine landings have dropped below levels observed before this period. Sardine and anchovy landings were, respectively, positively and negatively related to the AMO index and anchovy landings were also positively related to the WeMO. We finished by discussing the potential role of the environmental variables and fishing on long-term fishery landings trends.
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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 1054-3139 ISBN Médium
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Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1652
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Auteur (down) Van Beveren, E.; Fromentin, J.-M.; Bonhommeau, S.; Nieblas, A.-E.; Metral, L.; Brisset, B.; Jusup, M.; Bauer, R.K.; Brosset, P.; Saraux, C.
Titre Predator-prey interactions in the face of management regulations: changes in Mediterranean small pelagic species are not due to increased tuna predation Type Article scientifique
Année 2017 Publication Revue Abrégée Can. J. Fish. Aquat. Sci.
Volume 74 Numéro 9 Pages 1422-1430
Mots-Clés anchovy engraulis-encrasicolus; atlantic bluefin tuna; Energy density; fish condition; fisheries; food-consumption; Proximate composition; sea; thunnus-thynnus; Yellowfin tuna
Résumé Recently, the abundance of young Atlantic bluefin tuna (Thunnus thynnus) tripled in the northwestern Mediterranean following effective management measures. We investigated whether its predation on sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) could explain their concurrent size and biomass decline, which caused a fishery crisis. Combining the observed diet composition of bluefin tuna, their modelled daily energy requirements, their population size, and the abundance of prey species in the area, we calculated the proportion of the prey populations that were consumed by bluefin tuna annually over 2011-2013. To assess whether tuna could alter the size structure of the three small pelagic fish populations (anchovy, sardine, and sprat (Sprattus sprattus)), the size distributions of the consumed prey species were compared with those of the wild populations. We estimated that the annual consumption of small pelagic fish by bluefin tuna is less than 2% of the abundance of these populations. Furthermore, size selectivity patterns were not observed. We thus concluded that tuna predation is unlikely to be the main cause of major changes in the small pelagic fish populations from this area.
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Editeur Lieu de Publication Éditeur
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 0706-652x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2195
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Auteur (down) Torres-Irineo, E.; Dreyfus-Leon, M.; Gaertner, D.; Salas, S.; Marchal, P.
Titre Adaptive responses of tropical tuna purse-seiners under temporal regulations Type Article scientifique
Année 2017 Publication Revue Abrégée Ambio
Volume 46 Numéro 1 Pages 88-97
Mots-Clés atlantic; behavior; Closed season; eastern pacific-ocean; eastern tropical pacific; Fisher behaviour; Fisheries management; fishing strategies; fleet dynamics; mixed fisheries; model; Purse-seine fishing; state; trawlers; Tropical tuna
Résumé The failure to achieve fisheries management objectives has been broadly discussed in international meetings. Measuring the effects of fishery regulations is difficult due to the lack of detailed information. The yellowfin tuna fishery in the eastern Pacific Ocean offers an opportunity to evaluate the fishers' responses to temporal regulations. We used data from observers on-board Mexican purse-seine fleet, which is the main fleet fishing on dolphin-associated tuna schools. In 2002, the Inter-American Tropical Tuna Commission implemented a closed season to reduce fishing effort for this fishery. For the period 1992-2008, we analysed three fishery indicators using generalized estimating equations to evaluate the fishers' response to the closure. We found that purse-seiners decreased their time spent in port, increased their fishing sets, and maintained their proportion of successful fishing sets. Our results highlight the relevance of accounting for the fisher behaviour to understand fisheries dynamics when establishing management regulations.
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Editeur Lieu de Publication Éditeur
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 0044-7447 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2072
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