Estimating Reef Fish Populations in the Gulf of Mexico Using a Towed Camera System

To potentially better survey reef fish stocks, new optical methods of sampling are being developed at the University of South Florida in collaboration with the National Marine Fisheries Service.  The Camera-Based Assessment Survey System (C-BASS) is a towed platform equipped with video cameras and several environmental parameter sensors.  In 2013 and 2014, this system was tested in pilot surveys of the Florida Middle Grounds and Madison-Swanson protected areas on the West Florida Shelf.  Using count data from C-BASS imagery, the average densities of reef fishes were estimated and stratified by bottom type demonstrating clear differences in mean species density by habitat type.  The calculated mean densities were then used to estimate absolute abundances of reef fish populations by extrapolating over the entirety of the survey sites.  Observed reactive behavior was also analyzed to determine potential biases due to fish behavior on the fish counts made from C-BASS footage.  A majority of individuals analyzed were neutral or weakly deterred by the system which indicated an acceptable level of coverage is possible using C-BASS, especially for important reef fish fishes including snappers and groupers.