Benthic Features as a Determinant for Fish Biomass in Gray's Reef National Marine Sanctuary

Abstract

A recent focus of the National Oceanic and Atmospheric Administration (NOAA) National Marine Sanctuaries Program is the characterization and assessment of marine resources associated with coral reef and live bottom habitats in protected areas. Detailed bottom maps have been produced making it possible to quantify bottom features within Gray's Reef National Marine Sanctuary, Georgia, USA. Hydroacoustic fisheries surveys were used to estimate fish biomass in the context of underlying features and bottom types by applying spatial techniques and regression analysis. Variables relating bottom features to estimated fish biomass differed based upon depth in the water column. Distance to rock ledges was the best predictor of fish biomass in the bottom 2 m of the water column, whereas the area of two bottom habitat types combined was a reliable predictor of estimated fish biomass in the mid water column.