Consequences of an uncertain mass mortality regime triggered by climate variability on giant clam population management in the Pacific Ocean

Consequences of an uncertain mass mortality regime triggered by climate variability on giant clam population management in the Pacific Ocean Van Wynsberge S. auteur aut IRD Andréfouët Serge auteur aut IRD Gaertner-Mazouni N. auteur aut IRD Remoissenet G. auteur aut IRD text journalArticle eng text/pdf born digital access Despite actions to manage sustainably tropical Pacific Ocean reef fisheries, managers have faced failures and frustrations because of unpredicted mass mortality events triggered by climate variability. The consequences of these events on the long-term population dynamics of living resources need to be better understood for better management decisions. Here, we use a giant clam (Tridacna maxima) spatially explicit population model to compare the efficiency of several management strategies under various scenarios of natural mortality, including mass mortality due to climatic anomalies. The model was parameterized by in situ estimations of growth and mortality and fishing effort, and was validated by historical and new in situ surveys of giant clam stocks in two French Polynesia lagoons. Projections on the long run (100 years) suggested that the best management strategy was a decrease of fishing pressure through quota implementation, regardless of the mortality regime considered. In contrast, increasing the minimum legal size of catch and closing areas to fishing were less efficient. When high mortality occurred due to climate variability, the efficiency of all management scenarios decreased markedly. Simulating El Nifio Southern Oscillation event by adding temporal autocorrelation in natural mortality rates increased the natural variability of stocks, and also decreased the efficiency of management. These results highlight the difficulties that managers in small Pacific islands can expect in the future in the face of global warming, climate anomalies and new mass mortalities. specialized Climate change Stock decrease Lagoon enclosure Population viable analysis Spatially explicit modelling Tridacna maxima PACIFIQUE 036 040 021 Theoretical Population Biology 119 37-47 2018 0040-5809 https://www.documentation.ird.fr/hor/fdi:010072362 10.1016/j.tpb.2017.10.005 0040-5809 [F B010072362] https://www.documentation.ird.fr/hor/fdi:010072362 https://www.documentation.ird.fr/intranet/publi/2018/03/010072362.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2018-04-03 2023-07-11 fdi:010072362 fre