Clavareau L. auteur aut IRD Sabarros P. S. auteur aut IRD Escalle Lauriane auteur aut IRD Bach Pascal auteur aut IRD Abascal F. J. auteur aut IRD Lopez J. auteur aut IRD Murua H. auteur aut IRD Alayon P. J. P. auteur aut IRD Ramos M. L. auteur aut IRD Ruiz J. auteur aut IRD Merigot B. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Despite bycatch of elasmobranch (sharks and rays) being a major concern in most fisheries worldwide, there is a lack of knowledge on their spatio-temporal species distribution, biology (life stage and sex-ratios), as well as their at-haulback mortality rate. Observer data from the French and Spanish tropical purse-seine tuna fisheries operating in the eastern Atlantic and western Indian Oceans between 2005 and 2017 were analysed to investigate elasmobranch bycatch. Data included 24 elasmobranchs species and distribution patterns of catch per unit of effort (CPUE) by species and sex-ratio were found to vary with life stages, areas, seasons and fishing modes. In general, higher catches were found in FAD-associated sets (>40%) than free tuna school sets (<17%) although this can vary depending on the species. For the large majority of species, a high proportion of juveniles were caught (30.7-100%), apparent at-haulback mortality rates was high (24.3-63.9%) and finally sex ratios was unbalanced (13.3-66.7% of females). Areas and seasons identified from these different components should be of interest for the monitoring and management of elasmobranch bycatches. specialized Biodiversity Spatio-temporal distribution Life stage Sex ratio At-haulback mortality EUROPE FRANCE ESPAGNE ATLANTIQUE OCEAN INDIEN 040 034 24 e01211 [12 p.] 2020 2351-9894 https://www.documentation.ird.fr/hor/fdi:010080615 10.1016/j.gecco.2020.e01211 2351-9894 [F B010080615] https://www.documentation.ird.fr/hor/fdi:010080615 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers21-02/010080615.pdf IRD - Base Horizon / Pleins textes 2021-03-10 2025-02-24 fdi:010080615 fre