Global-scale environmental niche and habitat of blue shark (Prionace glauca) by size and sex: a pivotal step to improving stock management

Blue shark (Prionace glauca) is amongst the most abundant shark species in international trade, however this highly migratory species has little effective management. We combined 265,595 blue shark observations (capture or satellite tag) with environmental data to present the first global-scale analysis of species’ habitat preferences by size and sex classes (small juveniles, large juvenile males and females, adult males and females). We show that the lifetime foraging niche incorporates highly diverse biotic and abiotic conditions: the blue shark tends to shift from mesotrophic and temperate surface waters during juvenile stages to more oligotrophic and warm surface waters for adults. Large females tend to have greater habitat overlap with small juveniles than large males, more defined by temperature than productivity preferences. In particular, large juvenile females tend to extend their range into higher latitudes than large males, likely due to greater tolerance to relatively cold waters. Large females (FL above 125cm) also seem to avoid areas with intermediate SST (~21.7-24.0°C), resulting in separation from large males mostly in the tropical and temperate latitudes in the cold and warm seasons, respectively. Current management tends to ignore stage- and sex-specific habitat requirements of blue sharks, thus confounding attempts to improve management and conservation of this near-threatened species.

DRUON Jean-Noel;  CAMPANA Steven;  VANDEPERRE Frederic;  HAZIN Fabio;  BOWLBY Heather;  COELHO Rui;  QUEIROZ Nuno;  SERENA Fabrizio;  ABASCAL Francisco;  DAMALAS Dimitrios;  MUSYL Michael;  LOPEZ Jon;  BLOCK Barbara;  AFONSO Pedro;  DEWAR Heidi;  SABARROS Philippe;  FINUCCI Brit;  ZANZI Antonella;  BACH Pascal;  SENINA Inna;  GARIBALDI F.;  SIMS David;  NAVARRO Joan;  CERMEÑO Pablo;  LEONE Agostino;  DIEZ Guzman;  CARREÓN ZAPIAIN Maria Teresa;  DEFLORIO Michele;  ROMANOV Evgeny V.;  JUNG Armelle;  LAPINSKI Matthieu;  FRANCIS Malcolm P.;  HAZIN Humberto;  TRAVASSOS Paulo; 

2022-04-26

FRONTIERS MEDIA SA

JRC126294

2296-7745 (online),   

https://www.frontiersin.org/articles/10.3389/fmars.2022.828412,    https://publications.jrc.ec.europa.eu/repository/handle/JRC126294,   

10.3389/fmars.2022.828412 (online),