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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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Dagorn, Laurent; Holland, Kim N.; Hallier, Jean-pierre; Taquet, Marc; Moreno, Gala; Sancho, Gorka; Itano, David; Aumeeruddy, Ryaz; Girard, Charlotte; Million, Julien; Fonteneau, Alain. |
Yellowfin tuna (Thunnus albacares) are known to preferentially occupy the Surface mixed layer above the thermocline and it has been Suggested that they are physiologically restricted to water lerriperatt.11-CS no more than 8 degrees C colder than Surface waters. However, we here report for dive data acquired from a large yellowfin tuna which demonstrate for the first time that this species is indeed capable of making prolonged dives into deep cold waters. A yellowfin tuna (134 cm fork length) caught near ail anchored fish aggregating device (FAD) in the Seychelles (Western Indian Ocean) was equipped with all internally implanted archival tag and released. The fish was recaptured 98 days later. As predicted for this species, this fish spent 85% of its time... |
Tipo: Text |
Palavras-chave: Indian ocean; Yellowfin tuna; Swimming speed; Diving behavior; Vertical movements; Archival tap. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1402.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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