Estimating the footprint of pollution on coral reefs to inform management of land-use change

It is widely recognised that management of coastal marine ecosystems should encompass human impacts to watersheds. However, effective coastal management has been impeded by a lack of science that can link human activities in... [ view full abstract ]

It is widely recognised that management of coastal marine ecosystems should encompass human impacts to watersheds. However, effective coastal management has been impeded by a lack of science that can link human activities in watersheds to their impacts on coastal ecosystems. We developed a new Bayesian model that estimates the areal footprint of pollution from gradients of change in coral reef communities. We tested the model on lagoonal coral reefs subject to sedimentation from logging in the Kia region of the Solomon Islands. The model detected a gradient of change from communities dominated by soft-sediment, dead branching coral and massive corals close to logging activities, toward communities dominated by live branching corals further from logging activities. The new model enabled us to estimate that 60% of lagoonal reefs in the region had been affected by historical logging. The widespread impact of historical logging is of concern to local communities, because lagoonal reefs support important fisheries. We then estimated the area of reefs that might have been affected if recent illegal logging had not been halted. We thus show that models of community turnover can be used to estimate the areal impacts of historical pollution and evaluate the benefits of conservation activities for reef ecosystems and associated fisheries.