Pubblicazione scientifica

Vulnerability of the Oceanic Whitetip Shark to Pelagic Longline Fisheries

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità
produzione e cattura
produzione e raccolta

RIASSUNTO

A combination of fisheries dependent and independent data was used to assess the vulnerability of the oceanic whitetip shark to pelagic longline fisheries. The Brazilian tuna longline fleet, operating in the equatorial and southwestern Atlantic, is used as a case study. Fisheries dependent data include information from logbooks (from 1999 to 2011) and on-board observers (2004 to 2010), totaling 65,277 pelagic longline sets. Fisheries independent data were obtained from 8 oceanic whitetip sharks tagged with pop-up satellite archival tags in the area where longline fleet operated. Deployment periods varied from 60 to 178 days between 2010 and 2012. Tagging and pop-up sites were relatively close to each other, although individuals tended to travel long distances before returning to the tagging area. Some degree of site fidelity was observed. High utilization hotspots of tagged sharks fell inside the area under strongest fishing pressure. Despite the small sample size, a positive correlation between tag recorded information and catch data was detected. All sharks exhibited a strong preference for the warm and shallow waters of the mixed layer, spending on average more than 70% of the time above the thermocline and 95% above 120 m. Results indicate that the removal of shallow hooks on longline gear might be an efficient mitigation measure to reduce the bycatch of this pelagic shark species. The work also highlights the potential of tagging experiments to provide essential information for the development of spatio-temporal management measures.

DATA

Data di pubblicazione: 22/10/2015

AUTORI

TOLOTTI MARIANA TRAVASSOS
BACH PASCAL
HAZIN FABIO
TRAVASSOS PAULO
DAGORN LAURENT

ENTE DI AFFERENZA

Programa de Pós-graduação em Oceanografia Universidade Federal de Pernambuco Departamento de Oceanografia Recife—PE Brasil
Departamento de Pesca e Aquicultura Universidade Federal Rural de Pernambuco Recife—PE Brasil
INST RECHERCHE DEV UMR MARBEC IRD IFREMER UNIV MONTPELLIER CNRS
UC SANTA CRUZ DEPT ECOLOGY & EVOLUTIONARY BIOLOGY US

RIVISTA

PLoS ONE, 10(10), e0141396

IMPACT FACTOR

2,870

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