CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal; MARE, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, Cascais, Portugal
CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal; Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom
CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal; Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (IIM-CSIC), Vigo, Spain
Ana Couto
CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
Ivo da Costa
CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
António dos Santos
CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
Frederic Vandeperre
IMAR – Institute of Marine Research, Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal; MARE – Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal; Okeanos - Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal
Jorge Fontes
IMAR – Institute of Marine Research, Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal; Okeanos - Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal
Pedro Afonso
IMAR – Institute of Marine Research, Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal; Okeanos - Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal
Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom; Centre for Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom; Ocean and Earth Science, National Oceanography Centre Southampton, Waterfront Campus, University of Southampton, Southampton, United Kingdom
Climate-driven expansions of ocean hypoxic zones are predicted to concentrate pelagic fish in oxygenated surface layers, but how expanding hypoxia and fisheries will interact to affect threatened pelagic sharks remains unknown. Here, analysis of satellite-tracked blue sharks and environmental modelling in the eastern tropical Atlantic oxygen minimum zone (OMZ) shows shark maximum dive depths decreased due to combined effects of decreasing dissolved oxygen (DO) at depth, high sea surface temperatures, and increased surface-layer net primary production. Multiple factors associated with climate-driven deoxygenation contributed to blue shark vertical habitat compression, potentially increasing their vulnerability to surface fisheries. Greater intensity of longline fishing effort occurred above the OMZ compared to adjacent waters. Higher shark catches were associated with strong DO gradients, suggesting potential aggregation along suitable DO gradients contributed to habitat compression and higher fishing-induced mortality. Fisheries controls to counteract deoxygenation effects on shark catches will be needed as oceans continue warming.