Flower Garden Banks National Marine Sanctuary is one of 15 national marine sanctuaries and two marine national monuments protected by NOAA's Office of National Marine Sanctuaries. It is the only sanctuary site located in the Gulf of Mexico.
Situated 80 to 125 miles off the coasts of Texas and Louisiana, the Flower Garden Banks sanctuary includes thriving shallow water coral reefs, algal-sponge communities, and deeper mesophotic reefs full of black coral, octocoral, and algal nodule habitats.
The sanctuary protects portions of 17 separate reefs and banks in the northwestern Gulf of Mexico. These banks are a combination of small underwater mountains, ridges, troughs, and hard bottom patches along the continental shelf, created by underlying salt domes. Together, they create a chain of protected habitats for ecologically and economically important species across the northwestern Gulf of Mexico.
When first designated in 1992, the sanctuary consisted of only East and West Flower Garden Banks, home to some of the healthiest coral reefs in the world. These two banks, situated about about 13 miles apart, are located almost directly south of the Texas/Louisiana border.
Stetson Bank, located about 30 miles northwest of West Flower Garden Bank, off the coast of Texas, was added to the sanctuary in 1996.
In 2021, portions of 14 more reefs and banks were added to the sanctuary. These include Horseshoe Bank, located between East and West Flower Garden Banks, as well as MacNeil, Rankin, 28 Fathom, Bright, Geyer, Elvers, McGrail, Bouma, Sonnier, Rezak, Sidner, Parker, and Alderdice Banks to the east of the original sanctuary, off the coast of Louisiana.