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| Dortel, Emmanuelle; Sardenne, Fany; Bousquet, N.; Rivot, Etienne; Million, Julien; Le Croizier, Gael; Chassot, Emmanuel. |
| The Indian Ocean Tuna Tagging Program provided a unique opportunity to collect demographic data on the key commercially targeted tropical tuna species in the Indian Ocean. In this paper, we focused on estimating growth rates for one of these species, yellowfin (Thunnus albacares). Whilst most growth studies only draw on one data source, in this study we use a range of data sources: individual growth rates derived from yellowfin that were tagged and recaptured, direct age estimates obtained through otolith readings, and length-frequency data collected from the purse seine fishery between 2000 and 2010. To combine these data sources, we used an integrated Bayesian model that allowed us to account for the process and measurement errors associated with each... |
| Tipo: Text |
Palavras-chave: Indian Ocean yellowfin; Hierarchical Bayesian model; Tagging; Fisheries. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36513/35080.pdf |
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| Sardenne, Fany; Dortel, Emmanuelle; Le Croizier, Gael; Million, Julien; Labonne, Maylis; Leroy, Bruno; Bodin, Nathalie; Chassot, Emmanuel. |
| The Indian Ocean Tuna Tagging Program (IOTTP) provided a unique opportunity to assess the viability of estimating the age of tropical tunas from the micro-structural features of otoliths. Here, we analyzed the length measurements and micro-increment counts collected for 506 sagittal otoliths, of which 343 were chemically marked with oxytetracycline, for bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin tuna (Thunnus albacares). Our results show that the otoliths of tropical tunas grow more slowly than the rest of the body. Our findings confirm that both yellowfin and juvenile bigeye deposit daily increments in their otoliths, though ages are underestimated for large bigeye (>100 cm) when derived from micro-increment counts. Our... |
| Tipo: Text |
Palavras-chave: Daily age; Micro-increment; Mark-recapture; Oxytetracycline; Thunnus. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36511/35082.pdf |
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| Le Croizier, Gael; Schaal, Gauthier; Point, David; Le Loc'H, Francois; Machu, Eric; Fall, Massal; Munaron, Jean-marie; Boye, Aurelien; Walter, Pierre; Lae, Raymond; De Morais, Luis Tito. |
| Bioaccumulation of toxic metal elements including mercury (Hg) can be highly variable in marine fish species. Metal concentration is influenced by various species-specific physiological and ecological traits, including individual diet composition and foraging habitat. The impact of trophic ecology and habitat preference on Hg accumulation was analyzed through total Hg concentration and stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) analyses in the muscle of 132 fish belonging to 23 different species from the Senegalese coast (West Africa), where the marine ecosystem is submitted to nutrients inputs from various sources such as upwelling or rivers. Species-specific ecological traits were first investigated and results showed that vertical (i.e.... |
| Tipo: Text |
Palavras-chave: Methylmercury sources; Trophic ecology; Feeding habitat; Metal bioaccumulation; Chemical tracers; Isotopic niche. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00458/57013/58912.pdf |
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| Le Croizier, Gael; Lacroix, Camille; Artigaud, Sebastien; Le Floch, Stephane; Raffray, Jean; Penicaud, Virginie; Coquille, Valerie; Autier, Julien; Rouget, Marie-laure; Le Bayon, Nicolas; Lae, Raymond; De Morais, Luis Tito. |
| Impacted marine environments lead to metal accumulation in edible marine fish, ultimately impairing human health. Nevertheless, metal accumulation is highly variable among marine fish species. In addition to ecological features, differences in bioaccumulation can be attributed to species-related physiological processes, which were investigated in two marine fish present in the Canary Current Large Marine Ecosystem (CCLME), where natural and anthropogenic metal exposure occurs. The European sea bass Dicentrarchus labrax and Senegalese sole Solea senegalensis were exposed for two months to two environmentally realistic dietary cadmium (Cd) doses before a depuration period. Organotropism (i.e., Cd repartition between organs) was studied in two storage... |
| Tipo: Text |
Palavras-chave: Metal; Trace element; Dicentrarchus labrax; Solea senegalensis; Chronic dietary exposure. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00437/54810/56480.pdf |
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| Le Croizier, Gael; Lacroix, Camille; Artigaud, Sebastien; Le Floch, Stephane; Munaron, Jean-marie; Raffray, Jean; Penicaud, Virginie; Rouget, Marie-laure; Lae, Raymond; Tito De Morais, Luis. |
| Subcellular cadmium (Cd) partitioning was investigated in the liver of two marine fish species, the European sea bass Dicentrarchus labrax and the Senegalese sole Solea senegalensis, dietary exposed to an environmentally realistic Cd dose for two months followed by a two-month depuration. Cd exposure did not modify Cd cellular partitioning for either species, refuting the spillover hypothesis. Both species contained most of the Cd in the detoxifying fraction but displayed different handling strategies. Cd was largely bound to heat stable proteins (HSP) including metallothioneins (MT) in sea bass while Cd was more linked to metal rich granules (MRG) in sole. Whole liver concentrations and subcellular partitioning were also determined for essential elements.... |
| Tipo: Text |
Palavras-chave: Sub-cellular fractionation; Dicentrarchus labrax; Solea senegalensis; Essential element distribution; Elimination; Depuration. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00464/57606/59792.pdf |
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| Le Croizier, Gael; Schaal, Gauthier; Gallon, Regis; Fall, Massal; Le Grand, Fabienne; Munaron, Jean-marie; Rouget, Marie-laure; Machu, Eric; Le Loc'H, Francois; Lae, Raymond; De Morais, Luis Tito. |
| The link between trophic ecology and metal accumulation in marine fish species was investigated through a multi-tracers approach combining fatty acid (FA) and stable isotope (SI) analyses on fish from two contrasted sites on the coast of Senegal, one subjected to anthropogenic metal effluents and another one less impacted. The concentrations of thirteen trace metal elements (As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sn, U, and Zn) were measured in fish liver. Individuals from each site were classified into three distinct groups according to their liver FA and muscle SI compositions. Trace element concentrations were tested between groups revealing that bioaccumulation of several metals was clearly dependent on the trophic guild of fish. Furthermore,... |
| Tipo: Text |
Palavras-chave: Trace elements; Biochemical tracers; Diet; Contamination; Senegal; Tropical fish. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00348/45908/45707.pdf |
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