When large marine predators feed on fisheries catches: Global patterns of the depredation conflict and directions for coexistence

The sustainable mitigation of human–wildlife conflicts has become a major societaland environmental challenge globally. Among these conflicts, large marine predatorsfeeding on fisheries catches, a behaviour termed “depredation,” has emerged concomitantlywith the expansion of the world’s fisheries. Depredation poses threatsto both the socio-economic viability of fisheries and species conservation, stressingthe need for mitigation. This review synthesizes the extent and socio-ecologicalimpacts of depredation by sharks and marine mammals across the world, and thevarious approaches used to minimize it. Depredation was reported in 214 fisheriesbetween 1979 and 2019 (70% post-2000) and affected fleets from 44 countries, inall sectors (commercial, artisanal and recreational), and in all major fishing techniques(nets, traps and hook-and-lines). A total of 68 predator species were involved in depredation(20 odontocetes, 21 pinnipeds and 27 sharks), and most (73%) were subjectto either by-catch and/or retaliatory killing from fishers when interacting with gear.Impacts on fishers were primarily associated with catch losses and gear damage butoften lacked assessments. Deterrence was a major mitigation approach but also theleast effective. Gear modifications or behavioural adaptation by fishers were morepromising. This review highlights the need for improved monitoring, and interdisciplinaryand integrated research to quantify the determinants and impacts of depredationin the socio-ecological dimension. More importantly, as the conflict is likely toescalate, efforts directed towards changing perceptions and integrating knowledgethrough adaptive co-management are raised as key directions towards coexistencebetween fisheries and large marine predators.