Abstract

However, very little of its area has been mapped with enough resolution to accurately locate and quantify the hard/live bottom habitat these fisheries are so strongly tied to. Such maps are essential for designing an efficient fishery independent survey of reef fishes, enabling pre-stratification by habitat, and thereby minimizing variance and optimizing survey resources. Accurate habitat maps will also be critical for ecosystem based fisheries management and marine spatial planning. In support of a recently expanded fishery independent reef fish survey, the Panama City NMFS lab began mapping cross-shelf transects on the northern WFS using multibeam and side scan sonar. Two transects ~ 1.5-2.5 X 30 nm were mapped with a 300 kHz multibeam sonar and seventeen single swath cross-shelf transects ~20-30 nm X 150 m were mapped using a 600 kHz side scan sonar. An inexpensive live video drop camera and occasionally an ROV were used for visual ground truthing. Although the multibeam provided bathymetry and backscatter data at very high resolution, the side scan hardware and software was much more user friendly and provided data on which hard/live bottom habitat could, after a very short learning curve, be easily identified. Given the scale of most interest for fisheries-related needs, the 600 kHz side scan sonar may be the most cost-effective tool for our purposes.

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