Predicting the vulnerability of tropical reef fishes to exploitation with phylogenies and life histories

Fishing has led to local extirpations of reef fishes. For conservation and management purpose, it is important to identify all those species that are vulnerable to fishing, but this cannot be done using a priori assessments o r by describing trends in abundance because the necessary scientific resour ces are not available. Thus the predictions of vulnerability that provide t he basis for conservation action will have to be made with existing data or data that can be acquired rapidly before further extirpations occur. The l ife histories of species may determine their responses to exploitation, and we describe how an easily measured parameter, maximum observed size, is re lated to population trends of exploited fishes on coral reefs. Using a phyl ogenetic comparative approach, we demonstrated that species of grouper (Epi nephelinae), snapper (Lujanidae), and parrotfish (Scaridae) that decreased in abundance more than their nearest phylogenetic relative had greater maxi mum size. Our results suggest that one can predict the vulnerability of ree f fishes to exploitation based on responses of their relatives. The quality of the prediction was good for the intensively fished groupers and snapper s but poor for the lightly fished parrotfishes. Our approach may help proac tive conservationists and fishery managers identify and conserve vulnerable species in new, developing, or lightly exploited fisheries, thereby reduci ng their reliance on reactive management methods.