An integrated approach to determining the risk of over-exploitation for data-poor pelagic Atlantic sharks

We assessed the risk of over-exploitation for pelagic shark species taken in Atlantic longline fisheries based on three main metrics: Ecological Risk Assessment, the inflection point of the population growth curve (a proxy for BMSY) and IUCN Red List status. The results were analysed using multivariate statistics to provide an integrated measure of the risk of overexploitation. The integrated risk approach is not a substitute for stock assessment, but rather a method to aid in making science-based management recommendations in the face of data limitations. Findings for individual species were compared to that of the blue shark, a species that current stock assessments under the International Commission for the Conservation of Atlantic Tunas (ICCAT) indicate is not over-exploited. All examined pelagic shark and ray species had higher levels of risk than the blue shark. All species had substantially lower biological productivity than the blue shark and had inflection points above 50% of virgin biomass. According to our analyses, species at highest risk are the bigeye thresher, shortfin mako, longfin mako, and, to lesser extent, the silky shark. The porbeagle, oceanic whitetip and common thresher were grouped and identified as having the next greatest risk. The pelagic stingray and scalloped hammerhead ranked in line with the blue shark. Conclusions about the crocodile shark and smooth hammerhead could not be made due to a lack of data.