9781888569605-ch58

Benthic Habitats and the Effects of Fishing

Symposium Abstract: Integration of Acoustic Seabed Classification and Fish Census Data for Determining Appropriate Boundaries of Marine Protected Areas

A. C. R. Gleason, A. M. Ecklund, R. P. Reid, D. E. Harper, D. B. McClellan, and J. Schull

doi: https://doi.org/10.47886/9781888569605.ch58

In southern Florida, fine-scale benthic habitat maps are unavailable for water depths greater than 20 m because the depth is too great to effectively exploit traditional optical mapping methods. These deep water zones may, however, harbor diverse communities of benthic invertebrates and fish that are under-represented in most population surveys. In the Florida Keys, for example, SCUBA divers documented black grouper aggregations at 28 m depth, just seaward of a no-take zone within the Florida Keys National Marine Sanctuary, but the distribution of potential deep-water grouper spawning habitats in the Florida Keys is as yet unknown. Systematic mapping of the acoustic diversity of the sea floor (i.e. variations in response of diverse bottom types to an acoustic signal) offers a potential means for (1) identifying deep-water benthic habitats, (2) describing relationships between benthos and substrate on a regional scale, and (3) establishing effective boundaries of marine protected areas. We are currently using the sea bed classification system QTC VIEW system V to map bottom types in the vicinity of Carysfort reef, a known site of black grouper (Mycteroperca bonaci) aggregation. The acoustic mapping is being performed in coordination with diver-based surveys of fish populations. Mapping results guide the locations of dives, which are limited in time and scope due to water depth. Diver surveys, in turn, provide ground truth data to refine and adjust classification maps. Delimiting benthic habitats that are potential sites of grouper aggregation is critical to defining appropriate boundaries of marine reserves.