Ecological risk assessment of a pelagic seabird species in artisanal tuna fisheries

Abstract

Fishery bycatch is a serious threat to several protected, endangered, and threatened species (PETs), requiring urgent action to develop and implement conservation measures. This study performs an Ecological Risk Assessment for the Effects of Fishing (ERAEF) using a spatially and temporally Productivity-Susceptibility Analysis (PSA) to calculate the potential risk to great shearwaters (Ardenna gravis) from direct interaction with the metiers of the artisanal tuna fishing fleet at the Bay of Biscay (baitboats and trollers). The PSA incorporates productivity attributes based on the Fecundity Factor Index; and susceptibility attributes calculated from the species spatio-temporal abundance patterns obtained developing density surface models and distribution and intensity of fishing activity based on pooled Vessel Monitoring System and logbook data. The PSA shows an overall moderate risk to great shearwaters by the artisanal tuna fishery also revealing that baitboats are less risky than trollers (risk score of 3.12 +/- 0.09 and 2.70 +/- 0.05, respectively). Spatially, the likelihood of presence of high potential risk areas was associated with prey availability for both the PET and the commercial fish species. The systematic, repeatable, and standardized ERAEF followed in this study can be used to advice for ecosystem-based fisheries management to improve management measures for reducing bycatch of PETs around the world.