Appui au suivi de pêches récréatives et illégales au sein de la Réserve Naturelle Marine de la Réunion - Rapport 2022-2025

This report is one of the deliverables arising from the three initiatives set out in the collaboration agreements between the Réunion Marine Nature Reserve (RNMR) and Ifremer for the period 2022 to 2024. It presents the scientific support activities provided by Ifremer to the RNMR Public Interest Group (GIP), comprising mainly: A) a summary of trends in fishing effort and catches from various fishing practices by users on the reef flats managed by the RNMR in 2022, 2023 and 2024, B) a contribution to annual meetings aimed at facilitating dialogue and disseminating scientific knowledge to fishermen, managers and government bodies, and C) a review of the collection and processing of biological samples recovered during seizures of illegal fishing gear and catches carried out by RNMR officers during inspection missions. Monitoring data for so-called traditional shore fishing, practised on reef flats between 2008 and 2024, are analysed on the basis of annual fishing effort data, catch per unit of effort (CPUE) and catch size structures for three fishing methods: net fishing for the capucin nain (Mulloidichthys flavolineatus), rod fishing for the zourite (Octopus cyanea) and rod fishing for the macabit (Epinephelus merra and Epinephelus hexagonatus). For the capucin nain, fishing effort has increased in recent years, but there is no clear trend in CPUE. For the zourite, however, the continuous decline in CPUE over time indicates a critical situation for this resource. For the macabit, a first trial of stock assessment using SPICT suggests that exploitation is close to the Maximum Sustainable Yield (MSY) level. Management recommendations are proposed for each type of fishery. One chapter examines data on illegal fishing enforcement, which shows that the main technique subject to fines is spearfishing, both day and night, and that this technique is the most effective in terms of yield (catch per unit of effort) and targeting. The six main groups caught by illegal fishing, accounting for 70% of the catch weight, are herbivorous fish (scaridae and acanthuridae), octopuses (octopodidae), rock lobsters (palinuridae), groupers (serranidae) and goatfishes (mullidae). Monitoring of catches from illegal fishing has enabled the collection of biometric and biological data on more than 7,000 individuals since 2015, thereby contributing to the establishment of size-weight relationships and growth parameters for several species, some of which are listed in the European Data Collection Framework (DCF) regulation.