Seal depredation in bottom-set gillnet and entangling net fisheries in Irish waters

Reports from the fishing industry suggest that seal depredation in Irish bottom-set gillnets and entangling net fisheries has increased substantially in recent years. A dedicated observer program was conducted in a range of such fisheries off the southwest and west coasts of Ireland to provide the first quantitative estimates of seal depredation. Zero inflated negative binomial and Poisson regression models found positive correlations between depredation and factors such as latitude, depth, timing of a haul within a trip and quantities of gear hauled. Soak time was significant in the inshore gillnet fishery for pollack species (Pollachius spp.) but not significant in the deeper more offshore gillnet fishery for hake (Merluccius merluccius). Results suggest that soak times should be kept short in shallow areas while faster hauling speeds, and systems which actively deter seals from the vicinity of Vessels operating in deep water should be explored.