Mapping modeling Coral Reef Fish Habitat Use using Splitbeam and Multibeam Sonar Surveys

Baseline characterization of coral reef ecosystems informs marine spatial planning, marine reserve design and serves additional management and stakeholder needs.  Advances in semi-automated habitat mapping using hydroacoustic technologies has increased accuracy and efficiency in producing management-relevant data products in a timely fashion.  But in most cases, managers are charged with managing the living resources and fishes, rather than the habitats.  Further advances in hydroacoustics and data processing methods has also provided a means to rapidly map habitat use by reef fishes at resolutions and extents that are comparable to satellite imagery or sonar-derived habitat maps and at extents that are several orders of magnitude over existing diver methods.  We present advantages and challenges of using fisheries sonar in complex and diverse reef systems.  Spatially-explicit models are used to identify geomorphological and biological benthic features that influence the distribution and densities of coral reef fishes over a continuum of spatial and temporal scales.  Output from these models corroborates and advances prior landscape studies of coral reefs that have used visual census data to assess reef communities.  Factors such as rugosity, slope and biological cover explain the majority of variation in spatial distribution of fishes.  The greater extent and finer resolution afforded by the mobile hydroacoustic techniques enhances our interpretation of habitat use by reef fishes and increases the value of benthic habitat maps in coral reef management plans.