Stetson Bank Long-Term Monitoring: 2015-2018 Synthesis Report

This report documents methods, analyses, and results from annual long-term monitoring of fish and benthic communities at Stetson Bank over a period of four years, 2015–2018. Stetson Bank is an uplifted claystone/siltstone feature, located within Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico, that supports a well-developed coral community of tropical marine sponges and coral. 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 reduced diversity.

Monitoring has occurred on the bank crest (17-34 m) of the site since 1993. In 2015, monitoring efforts were expanded to include the deeper mesophotic habitat (34–64 m) surrounding the bank crest. The bank crest benthic community at Stetson Bank has undergone several significant shifts, changing from a habitat of predominantly hydrocoral and sponges to one of macroalgae and sponges. The fish community on the bank crest has been highly variable each year. Fluctuations in oceanic conditions, fluctuations in macroalgae cover, and continued annual variation in fish communities were documented. Additionally, an exotic species arrived and a baseline characterization of mesophotic communities was established.

Keywords

benthic community, fish community, Flower Garden Banks National Marine Sanctuary, long-term monitoring, mesophotic coral ecosystem, Stetson Bank, water quality