Infodoc : Sciences, Techniques et Culture

With only 2.7% of the oceans currently fully protected, there is a desire to increase the area of no-take marine protected areas since international organizations are aiming to protect30% of the oceans by 2030. This would exclude large parts of the ocean from fishing, potentially depriving people of their livelihoods and an important food source. However, marine reserves might also benefit surrounding fisheries grounds through the spill over of juveniles and adults, or the transport of eggs and larvae outside a reserve. Here, we model the potential dispersal of fish from marine reserves by using the BiOeconomic mArineTrophic Size-spectrum (BOATS) model, which estimates fish biomass globally on a fine spatialgrid. A limitation of this model is that each grid cell is independent, thus, [...]

With only 2.7% of the oceans currently fully protected, there is a desire to increase the area of no-take marine protected areas since international organizations are aiming to protect30% of the oceans by 2030. This would exclude large parts of the ocean from fishing, potentially depriving people of their livelihoods and an important food source. However, marine reserves might also benefit surrounding fisheries grounds through the spill over of juveniles and adults, or the transport of eggs and larvae outside a reserve. Here, we model the potential dispersal of fish from marine reserves by using the BiOeconomic mArineTrophic Size-spectrum (BOATS) model, which estimates fish biomass globally on a fine spatialgrid. A limitation of this model is that each grid cell is independent, thus, we expandedBOATS by including inter-cell movement of fish, based on the diffusion equation. We thus estimate the potential fisheries benefits of marine reserves at a local and global scale. When we compared an MPA network that covers 5% of the ocean with a hypothetical ocean with no MPAs, there was an overall decline in global fish catch of ~6%. When dispersal of adultfish was included, we found that the global decline in fish catch was reduced, but onlyslightly, with
Seulement 2,7 % des océans sont actuellement protégés, les institutions internationales visent une protection de 30% des océans d’ici 2030, donc elles poussent pour une augmentation du réseau d’aires protégées. Toutefois, cela reviendrait à soustraire de grandes parties de l'océan à la pêche, privant ainsi potentiellement les populations de leurs moyens de subsistance et d'une importante source de nourriture. Cependant, les réserves marines pourraient également profiter aux zones de pêche environnantes par le biais de l’exportation des juvéniles et des adultes, ou du transport d’œuf et de larve hors d'une réserve. Nous modélisons ici la dispersion potentielle des poissons provenant des réserves marines en utilisant le modèle BOATS (BiOeconomic mArine Trophic Size-spectrum) qui estime la biomasse de poissons à l'échelle mondiale sur une grille spatiale fine. Une des limites de ce modèle vient de l’indépendance des cellules, nous avons donc étendu BOATSen incluant un mouvement intercellulaire des poissons basé sur une équation de diffusion. Nous estimerons les bénéfices potentiels des réserves marines pour la pêche à une échelle locale et globale. Nous avons constaté une baisse de la pêche globale de ~6% lorsque nous mettons en place un réseau d’aires protégées couvrant 5% de l’océan. Ce déclin global est légèrement réduit lorsque le mouvement des poissons adultes est inclus, on observe une diminution de