Mitigating dolphin depredation in Mediterranean fisheries: results and insights from collaborative efforts for cetacean conservation and sustainable fisheries

With the Ministerial Declaration on the Regional Plan of Action for Small-Scale Fisheries in the Mediterranean and the Black Sea (RPOA-SSF) signed in Malta on September 26, 2018, the General Fisheries Commission for the Mediterranean (GFCM), and 18 Mediterranean and Black Sea countries, as well as the European Union, have committed themselves to take concrete actions aimed at ensuring the long-term environmental, economic and social sustainability of small-scale fisheries within the next decade. The principles and objectives of the Plan take into account the factors increasingly threatening the sustainability of the regional fisheries, including pollution from human activities, habitat degradation, introduction of non-indigenous species, overfishing, and impacts of climate-driven changes on the marine ecosystems.

Depredation by cetaceans, primarily dolphins, poses a natural threat to the economic sustainability of fisheries by removing catches from gear, leading to gear damage, lost catches, and conflicts between fishers and dolphins. These events undermine the conservation and sustainability efforts promoted by regional organizations such as the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area (ACCOBAMS), GFCM, the Specially Protected Areas Regional Activity Centre (SPA/RAC) of the UN Environment Mediterranean Action Plan, and the Low Impact Fishers of Europe platform (LIFE) emphasizing the urgency of responding to the depredation issue when managing fisheries in the region, in line with an ecosystem approach to fisheries.

This presentation provides results from the monitoring programs and mitigation trials tested in five pilot sites from the Western and the Central Mediterranean Sea for assessing and mitigating the depredation caused by bottlenose dolphins in purse seine fisheries (in Morocco and Tunisia), and by different cetacean species in small-scale fisheries (in Italy, Malta and Spain).

Data collection and analysis have been accomplished, based on standardized research protocols, as part of the “Mitigating dolphin depredation in Mediterranean fisheries – Joining efforts for strengthening cetacean conservation and sustainable fisheries” project coordinated by ACCOBAMS and the GFCM, in collaboration with SPA/RAC, and LIFE. This initiative strengthens regional capacities to address the complex challenges posed by cetacean-fishery interactions, contributing to broader biodiversity conservation and sustainable fisheries management in the Mediterranean.

Indeed, cetacean-fishery interactions often arise from spatial overlap, as both cetaceans and humans target the same species. The bottlenose dolphin (Tursiops truncatus), a coastal species frequently involved in depredation, affects up to 53% of fishing trips for some fleets. Damage includes bite marks, holes, and fish heads left in nets, bent hooks and scattered fish schools in longlines, reducing catch value and requiring costly repairs, sometimes up to EUR 600 per month.

Funded by the MAVA Foundation (2018-2022), the project aimed to monitor and reduce cetacean depredation in Mediterranean fisheries, advancing understanding of the phenomenon through standardized assessment methods and testing mitigation measures for fishers.

Effectively tackling bycatch and depredation demands a deep understanding of cetacean populations, their distribution, and the complex dynamics of their interactions with fisheries.