Quantifying horizontal overlap between longline fleets and porbeagle distribution for ecological risk assessment
The Sustainability Assessment for Fishing Effects (SAFE) ecological risk assessment was updated by the Sharks Working group for the 2020 assessment of porbeagle shark (Lamna nasus). This paper describes how distribution information for the Northern and Southern stocks was evaluated relative to fishing effort to determine the extent of geographical overlap (i.e. availability) of porbeagle to commercial fishing activity. Availability was calculated as the amount of the porbeagle distribution (5x5 degree resolution) used by the fishery divided by the total area of the porbeagle distribution in the North or South Atlantic. For comparison, the proportion of fishing effort that overlaps with porbeagle relative to the total amount of fishing effort was also calculated in the North and South Atlantic.