2016 Flower Garden Banks National Marine Sanctuary Long-Term Monitoring of the Reef Crest and Mesophotic Benthic and Fish Communities of Stetson Bank, northwestern Gulf of Mexico (NCEI Accession 0243647)

This dataset contains raw and processed data from an annual long-term monitoring study that documents the benthic and fish community changes at Stetson Bank, in the Flower Garden Banks National Marine Sanctuary. Stetson Bank is an uplifted claystone/siltstone feature, located 75 nautical miles from Galveston, TX in the northwestern Gulf of Mexico, that supports a well-developed benthic community of scleractinian coral and tropical marine sponges. Due to a wide range of temperatures and variable light availability, Stetson Bank has marginal environmental conditions for coral reef development and growth. The fish community is similar to other Caribbean reefs but has comparatively lower diversity.

Monitoring has occurred on the bank crest (17-34 m) of the site since 1993. Bank crest monitoring includes random transect and repetitive photostation photographs of the benthos to estimate percent cover of major taxonomic groups (e.g., coral, sponge, algae). Benthic photographs are analyzed using Coral Point Count (CPCe) and output into Microsoft Excel worksheets. These data are analyzed for temporal community changes in Primer. Fish census surveys are conducted annually using a modified Bohnsack and Bannerot stationary method, both at random and repetitive sites. Fish data are recorded in Microsoft Excel worksheets. Primer software is used to identify any temporal shifts that occur in the fish community. Water quality parameters (e.g., temperature, salinity, turbidity, nutrients) are measured with moored conductivity temperature depth (CTD) instruments and quarterly profiles of the water column are performed. Temperature and salinity data are reduced to report daily averages.

In 2015, monitoring efforts were expanded to include the deeper mesophotic habitat (34-64 m) surrounding the bank crest using a remotely operated vehicle (ROV). Mesophotic monitoring includes random transect and repetitive photostation photographs of the benthos to estimate percent cover of major taxonomic groups (e.g., coral, sponge, algae). Repetitive photostation images are only assessed using qualitative summaries of key species identified in 2015 during installation. Random transect photographs are analyzed using Coral Point Count (CPCe) and output into Microsoft Excel worksheets. These data are analyzed for temporal community changes in Primer. Fish census surveys are conducted annually in conjunction with benthic transect surveys. Fish data are recorded in Microsoft Excel worksheets. Primer software is used to identify any temporal shifts that occur in the fish community.

The bank crest benthic community at Stetson Bank has undergone several significant shifts, changing from a habitat predominated by hydrocoral and sponges to one of macroalgae and sponges. The fish community on the bank crest has varied annually. Exotic fish species are present at the bank, including lionfish (Pterois volitans/P. miles) and regal demoiselle (Neopomacentrus cyanomos). Fluctuations in oceanic conditions, macroalgae cover, and continued annual variation in fish communities were documented.