Analysis of Bathymetric Data to Prioritize Protection of Fish Habitat Sites

Marine fish sampling provides data important for sustainable fisheries management, but comprehensive offshore fish surveys are resource intensive and dependent on sea conditions.  Hard-substrate sites off Texas provide rare fish habitat with bathymetric relief on the flat, soft-sediment continental shelf.  Few biological data exist for such sites, but fishermen regularly target these South Texas Banks.  In areas with few biological data, abiotic variables are used commonly as surrogates for marine biodiversity.  Over 20 South Texas Banks are known, but few have been explored.  This study focused on 12 outer-shelf banks that support ecological connectivity among nearshore and offshore, hard-bottom, natural and artificial sites.  High-resolution bathymetric data were used to create maps and a dataset of geomorphic variables.  Multivariate analyses resulted in an abiotic surrogate for biodiversity patterns.  Patterns correspond with patterns from fish surveys performed at six sites.  Detailed maps and statistical results are important tools for studies to identify reef fish spawning sites and biodiversity trends.  The statistical approach produced a ranking tool to guide prioritization of future explorations and site selection for design of marine protected areas.  Remotely sensed bathymetric data collection provides a large dataset and is less resource intensive than comprehensive fish surveys.