Efficacy of a novel shark bycatch mitigation device in a tuna longline fishery

Elasmobranchs (sharks, rays, and skates) are caught throughout fisheries globally, leading to over one-third of species being threatened with extinction.
. Oceanic shark populations have undergone an average 71% decline over the last half century, owing to an 18-fold increase in relative fishing pressure.
. Incidental capture or ‘bycatch’ is a primary driver of population declines, and poses an important challenge for species conservation.
. This threat necessitates mitigation strategies that exist for sharks but are often focussed on haul-back and post-capture effects for longline fishing. We trialled a novel shark bycatch mitigation device (“SharkGuard”) in a commercial longline fishery targeting bluefin tuna (Thunnus thynnus), where bycatch consists largely of blue sharks (Prionace glauca) and pelagic stingrays (Pteroplatytrygon violacea).

Also published as IOTC-2023-WPEB19-INF14.