Linking ecological and social knowledge towards sustainable coral reef fisheries

Overfishing on coral reefs is a key threat to the structure, function and resilience of coral reefs and the well-being of dependent human populations. Despite their global socio-economic importance and biodiversity value, knowledge of sustainable management of coral reef fisheries remains poor. I use an interdisciplinary approach to explore the consequences of exploitation of reef fisheries by integrating global-scale island nation landings statistics with local-scale social knowledge. Globally, catches of reef fishes on islands varied considerably, and increased with human population density. High-yielding fisheries were sustained by greater proportions of lower trophic level taxa, had overexploited fisheries exploitation status, and tended to be found within the Indian and Atlantic Oceans. Islands with overexploited fisheries tended to be larger, with smaller reef area: land area ratios, greater dependence on reef resources, and higher levels of socioeconomic development (GDP). Conversely, sparsely-populated Pacific islands were underexploited with larger reef area: land area ratios and lower levels of GDP. Maximum sustainable yield for island coral reef fisheries was estimated using surplus production methods, and ranged from ~8.2-22.7 mt●km-2●yr-1, depending on the exploitation status of islands incorporated into the models. Results suggest yields > ~8mt●km-2●yr-1 may lead to overexploitation, highlighting the need to set conservative targets for their sustainable use. In contrast to global-scale spatial analyses, local social knowledge of fishers on the island of Anguilla revealed temporal declines in reef catches in recent decades, despite Anguillian reef fisheries being described as underexploited. This suggests that official landings statistics are highly conservative and highlights the importance of fisheries- independent information in understanding local-scale resource use and management on coral reefs. Sustaining reef fisheries for future generations requires an interdisciplinary approach combining ecological and societal knowledge that seeks to address the multiple underlying causes of reef degradation