Marine ecosystem goods and services, such as protein provision, are being affected by a range of anthropogenic stressors, and maintaining their integrity represents an important goal of conservation and management. For example, coral reef fisheries are vital to Micronesian economies, but may be overexploited. As part of The Nature Conservancy’s Mapping Ocean Wealth project, we assembled a database of 1127 fish surveys across five jurisdictions of Micronesia (the Republic of Palau, the Federated States of Micronesia, the Territory of Guam, the Commonwealth of the Northern Marianas, and the Republic of the Marshall Islands) to model and map fishing pressure and current standing stocks. A GIS of 22 potential predictor variables, including human population size, distance to markets, and oceanic temperature and productivity, were used to model fishing pressure and current and potential standing stock at a 1 ha resolution across the study area.
Results/Conclusions
Using mean parrotfish size as an indicator of fishing pressure and controlling for biophysical gradients, we demonstrate that fishing is best predicted by distance to the nearest port and human population pressure within 200 km. This metric of fishing pressure and biophysical variables were then used to model standing stock. Standing stock increased with increasing oceanic productivity, upstream larval supply, depth, and coral cover, and decreased with increasing sea surface temperature and fishing pressure. The models were then used to predict fishing pressure and current standing stock across all reefs in the study area, providing the first continuous maps of these variables for Micronesia. Furthermore, we mapped potential gains in standing stock that might be obtained in no-take reserves by simulating zero fishing pressure. The ratio of current to potential standing stock also generated spatially explicit estimates of fisheries status and potential time to recovery. Finally, the models also provide insights into the impacts of rising sea surface temperatures that are expected to alter fish distributions and reduce body size. These maps and models are important regional resources to inform policy and aid protected area design and fisheries management.