9781888569605-ch19

Benthic Habitats and the Effects of Fishing

Symposium Abstract: Benthic Habitat Characterization of the Grays Reef National Marine Sanctuary Using Sidescan, Multibeam, and GIS Techniques

C. Alexander, G. McFall, T. Battista, and R. Bohne

doi: https://doi.org/10.47886/9781888569605.ch19

NOAA’s Grays Reef National Marine Sanctuary has been completely mapped by the NOAA ship Whiting using multibeam and sidescan sonar techniques. The resulting data mosaics portray the geologic controls on the character of reef habitat as well as the signatures of modern processes affecting the reef. The multibeam data differentiate between the rocky and sandy habitats and illustrate the influence of pre-existing geologic structure on the general morphology of the reef. Sidescan data highlight the fine-scale detail of the rugged reef surface, the influence of bioerosion on the reef surface and the dynamics of mobile, unconsolidated sediments, which periodically alter reef benthic habitats by covering and exposing rocky substrate. GIS techniques, coupled with the high-resolution sidescan data, are being employed to automatically resolve and classify benthic habitats. Diver observations of fish distributions will be compared to benthic habitat distribution determined from the sidescan and multibeam datasets.