‭Shark bycatch mitigation project‬ ‭and Scientific activities on‬ ‭Depredation ‬‭in New-Caledonia‬

The New-Caledonian longline fleet operates exclusively within the EEZ of New-Caledonia in one of the biggest Marine Protected Areas in the word, the Natural Park of the Coral Sea. These waters are a sanctuary for sharks (Elasmobranchii) and some marine mammals (Mysticeti and some Odontoceti) with which the fishing activity has to cohabit. This can lead to direct or indirect interactions between fisheries and marine predators that can impact one another through accidental catches, predation on baits but also through depredation (damage or removal of target catch by predators). New Caledonia is continuously working in collaboration with the fishing companies to improve practices to limit these interactions and ensure the long-term conservation of these species as well as the economic viability of the fishery. In 2023, the fishery took part in sea trials testing a novel shark deterrent device developed by Fishtek Marine called SharkGuard®. SharkGuard attaches to branchlines (above the baited hook) and emits a powerful electric field designed to deter sharks and rays from being caught. During these trials an experimental part of the lines was equipped with the device to test its effectiveness and its impact on teleost CPUE. The analysis of the collected data showed no significant reduction in teleost CPUE with the use of SharkGuard and a 57% reduction in elasmobranch catch - noting that this last result wasn’t significant due to data power issues. In order to enhance the data power more trials are to be carried out in the future. These last 3 years, following concerns expressed by local fishing companies about increasing depredation events by sharks and odontocetes, New-Caledonia with the support of SPC-South Pacific Community and IRD-French National Research Institute for Sustainable Development have launched a project to characterize and assess the depredation phenomenon. So far, the analysis of the available data from 2002 to 2022 showed that while shark depredation occurred more frequently than odontocete depredation (58.5% vs. 9.2% of the longline sets), they damaged a lower proportion of fish (3.9% vs. 12.3%). It also shows a selective depredation of odontocetes on tuna species compared to sharks. These results indicate that depredation in the New Caledonian longline fishery is high compared to other regions and provide essential information on the dynamics and impacts of the issue as a basis for developing effective mitigation solutions.