Use of a Towed Camera System Indexing Reef Fish Population Densities in the Gulf of Mexico

The development of rapid assessment methods to estimate abundances and map the ranges of exploited fishes is of great priority for scientific and management purposes.  These data are integral for the management of fisheries targeted species and evaluations of conservation alternatives such as marine protected areas.  Here we present such data gathered using a newly developed towed camera system, C-BASS (Camera-Based Assessment Survey System).  This platform has the capability to facilitate large-scale, quantitative reef fish assessments and complement traditional sampling methods. Three protected areas on the West Florida Shelf in the Gulf of Mexico were surveyed during this study: Steamboat Lumps, Madison-Swanson, and the Florida Middle Grounds.  Contemporaneously with video footage, altitude above bottom, depth and environmental data – temperature, salinity, turbidity, chlorophyll –were continuously recorded during deployment.  This system’s utility is enhanced through the simultaneous use of high resolution hydroacoustics (EK-60) to estimate the fraction of fish occurring above the towing altitude.  We provide density estimates as well as data on spatial patterns and associations of selected reef fish species which are vital to understanding fish community dynamics.  Potential biases and uncertainties in these estimates are also discussed.