A quantitative assessment of the status of reef fish communities from a large-scale probability survey in southern Florida

Abstract

Numerous reef fish monitoring programs worldwide produce the data necessary to describe the status and trends of coral reefs; however, quantitative description of status at ecosystem scales has been challenging. Our goal was to use southern Florida’s coral reefs as the template to complete a holistic, ecosystem-scale evaluation of reef fish community status using large-scale diver surveys that sampled across a spatial gradient of human urbanization, exploitation, and fishery protection. Key aspects of the analysis were: (i) identification of a low human impact reference area as the basis for quantifying resource condition; (ii) selection of indicator variables that helped discriminate two classes of impacts: habitat quality and fishing; (iii) application of estimation methods that facilitated distinguishing anthropogenic impacts from inherent productivity of different habitats; and (iv) use of a sustainability benchmark to gauge the resource condition of the reference area. The reference-centering analysis approach reduced reliance on qualitative judgements by an expert panel and outputted results on a scale that was informative and could be easily interpreted by a variety of audiences. Our findings identified habitat quality issues in the most urbanized region, southeast Florida, and pervasive fishing issues throughout the ecosystem, including the remote Dry Tortugas region.