| Summary: | 355 pages [EN] In the present work, key aspects of the biology and ecology of the shortfin mako were studied. Feeding habits, analysed in two ocean basins, indicated that pelagic fish and cephalopods were the main prey items. In the South Pacific Ocean, a marked sexual segregation was found, with females being more common in the SE region; this was also the area with a higher abundance of juveniles and of late-stage pregnant females. In the North Atlantic Ocean, large-scale horizontal movements (including trans-Atlantic migrations) were identified and diel vertical behaviour patterns described. Importantly, individuals that performed wider movements away from the tagging location were less at risk from surface longline fishing. Using tagging and recapture data that spanned a ten-year period, survival, dispersal, and fishing mortality rates for both mako and blue sharks were estimated. The presence of plastics and hooks was also observed for both species, in two studied ocean basins. Finally, bycatch rates for other internationally protected shark species that are commonly caught using surface longlines was estimated based on direct observations, which were several times higher than the official reported data. The results presented here are especially relevant for improving the management measures focused on pelagic sharks [ES] En el presente trabajo se estudiaron diferentes aspectos importantes de la biología y ecología del marrajo azul. Los hábitos alimentarios analizados en dos cuencas oceánicas indicaron que los peces y los cefalópodos pelágicos fueron las presas mayoritarias. Se constató una marcada segregación sexual en el Pacífico, además de un área de agrupación de juveniles hacia la que parecen viajar las hembras preñadas. En el Atlántico se identificaron los movimientos horizontales a gran escala y se estudió el comportamiento vertical diario, observando que aquellos ejemplares que realizan mayores desplazamientos están en un menor riesgo frente a la pesca industrial. Se estimaron, gracias al ...
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