Bodin Nathalie auteur aut IRD Lucas V. auteur aut IRD Dewals Patrice auteur aut IRD Adeline M. auteur aut IRD Esparon J. auteur aut IRD Chassot Emmanuel auteur aut IRD text journalArticle eng text/pdf born digital access The use of a multi-ecological tracer approach provides valuable and complementary insights to investigate the complex biology and ecology of large pelagic fish. Brine immersion freezing is the most common preservation technique used onboard for large fish to be frozen whole until they are delivered for sale and processing. We evaluated the effect of brine freezing on lipid and fatty acid composition, C and N stable isotope ratios, and organochlorine contaminant levels of yellowfin tuna (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis). Fresh tunas were stored in a saturated sodium chlorine brine immersion tank maintained at -20 A degrees C for 6 weeks, and ecological tracers were analysed on dorsal muscle samples collected before and after brine freezing. No significant effect of the fish preservation technique was found except for delta N-15 whose signatures slightly increased after a 6-week period of brine immersion. Because N isotopic shift was close to the analytical precision and probably related to a higher risk of salt penetration in small tunas with abraded skin, we consider our results as conservative and conclude that ecological tracers can indeed be analysed on brine-freezing-preserved tunas. specialized Brine immersion Large pelagic fish Frozen storage Stable isotopes Fatty acids Persistent organic pollutants OCEAN INDIEN OUEST 054 020 036 038 238 6 1057-1062 2014 1438-2377 https://www.documentation.ird.fr/hor/fdi:010062063 10.1007/s00217-014-2210-3 1438-2377 [F B010062063] https://www.documentation.ird.fr/hor/fdi:010062063 https://www.documentation.ird.fr/intranet/publi/2014/06/010062063.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2014-07-03 2017-08-23 fdi:010062063 fre