TEXAS GEMS -FLOWER GARDEN BANKS NATIONAL MARINE SANCTUARY

 

Site Description

Flower Garden Banks was designated as a National Sanctuary on January 17, 1992; Stetson Bank was added in October, 1996. It ia located approximately 110 miles south of the Texas / Louisiana border, the Flower Garden Banks National Marine Sanctuary includes three banks: East Flower Garden, West Flower Garden, and Stetson. The Banks are perched atop salt domes rising above the ocean floor. The Flower Garden Banks harbor the northernmost coral reefs in the United States. Although not as biologically diverse as most tropical reefs, they are regional reservoirs of shallow-water Caribbean reef fishes and invertebrates in the northern Gulf of Mexico. Stetson Bank, 30 miles closer to shore, is a clay/siltstone bank dominated by sponges and fire coral. It supports an extraordinary fish community but is not a coral reef. Increased existing and potential impacts from anchor damage, oil and gas exploration / production /transportation, over fishing, and souvenir collecting prompted protection of the three banks.

Area of Influence:

The sanctuary is influenced by currents flowing around the Yucatan peninsula and northward along the coasts of Mexico and Texas. The area is also affected by eddies originating from the loop current in the eastern Gulf of Mexico. Although two-thirds of the United States drains into the Gulf of Mexico, negative impacts from major river systems such as the Mississippi and the Rio Grande have so far not been observed, probably because of the sanctuary's distance from the shore.

Ecological and Cultural Characteristics

Habitat Type:

Flower Garden Banks - pelagic zone, coral reef (high diversity and low diversity zones), coral line algae, algae-sponge, brine seep chemosynthetic community (East Bank only), drowned reefs, sand bottom.
Stetson Bank - pelagic zone, clay/siltstone bedrock, fire coral/sponge community, scattered coral colonies.

Rare/Endangered Species:

The species best known to the sanctuary are the loggerhead sea turtles, the leatherback sea turtles, and the hawksbill sea turtles.

Breeding/Nursery Area:

All banks are breeding and nursery areas for many tropical reef fish species.
Recent research indicates that the Flower Gardens may also serve as a nursery area for juvenile manta rays.

Forage Area:

All three banks are thought to support a balance of trophic levels among reef fish species; larger species foraging in the area include manta rays, sea turtles (primarily loggerhead), and several species of sharks (including occasional whale sharks).

Migratory Species:

Hammerhead sharks - winter (Jan. - April)

Spotted eagle rays - spring

Adult Manta Rays - seen more frequently in winter months

Sea turtle

Geomorphic Features:

Salt domes (diapirs - all banks)

Brine seep (East Flower Garden Bank)

Coral reefs (East & West Flower Garden banks)

Ecosystem Function:

Serves as a biological reservoir of Caribbean species in the northern Gulf of Mexico.

Uniqueness of Natural Community:

Average 50% coral cover at Flower Garden Banks

More than 21 species of coral

175 species of fish

More than 250 species of macro-invertebrates

More than 80 species of algae

Although species diversity is less than that of most Caribbean coral reefs, the ecology of the Flower Garden Banks and Stetson Bank are considered to be well-balanced in terms of the structural and functional elements, which include critical trophic levels and species interaction.

Archaeological and Cultural Significance:

The sanctuary does not include any known archaeological sites The Flower Gardens were discovered and named in the early 1900s by snapper fishermen. They pulled up bits of brightly colored sponges, corals and algae that snagged on their lines, which were responsible for the name Flower Gardens.

Current and Potential Use of the Site

Recreational Use:

Primary user group is recreational scuba divers. Some recreational fishing (spear fishing is not allowed; hook and line fishing is allowed). Some commercial fishing (primarily snapper - bottom long lining is not allowed); parts of the sanctuary are open for oil and gas production; these areas are outside the Minerals Management "no activity zone" but inside the sanctuary boundaries.

Site is used by academia and some non-profit organizations for research; permits are required to conduct most research and private commercial dive charters (ecotourism). Moorings occasionally used by transitory sailboats and yachts.

Management Status

Land Ownership:

Site is federal land under the jurisdiction of the U.S. Department of Commerce, National Oceanic & Atmospheric Administration, National Ocean Service, Office of Coastal Resource Management, Sanctuary & Reserves Division. Oil and gas leasing authority is held by the U.S Department of Interior, Minerals Management Service.

Existing Designations:

Designated National Marine Sanctuary (federal program) under the Sanctuaries Act of 1972.

Management Status:

Sanctuary has been left in natural state except for slight modifications (e.g. mooring buoys, marked monitoring stations) to enable mooring of vessels and long term monitoring. Sanctuary is managed by federal government (see ownership). Management involves research, education, physical interventions (e.g. installation of mooring buoys), regulations, enforcement, and making a concerted effort to involve partners from both public and private sectors.

Existing Monitoring Activities:

Researchers from Texas A&M University and other institutions have studied the site since the late 1960s. Minerals Management Service (U.S. Department of Interior) has monitored the site since the early 1970s. Currently, monitoring is conducted annually and includes the following parameters: coral cover and population, coral growth rates, temperature and light measurements, water quality testing.

Management Needs:

Physical interventions - radar reflecting navigation buoy on each bank.

Research - studies on genetic isolation, recovery potential, and resistance to stress

Monitoring - partnership between federal agencies and users to ensure long term commitment to monitoring.

Education - listing on international shipping charts as a protected area; increased education to user groups regarding potential impacts to natural resources in sanctuary (recreational divers, oil and gas industry, recreational and commercial fishers).

Tools - GIS database for management, research, and education.

Site Viability

Threats to Ecological Integrity:

Anchoring, particularly by foreign-flagged vessels.

Cumulative impacts from recreational diving activities.

Cumulative impacts from commercial fishing (legal and illegal).

Small potential for impacts from oil and gas exploration, production and transportation; impacts would probably be greatest if a spill were to occur over the Flower Gardens during the annual mass spawning.

Management Potential:

Partnerships between agencies with varying authority (e.g. NOAA, U.S. Coast Guard, Minerals Management Service, National Marine Fisheries Service) and users (oil and gas industry, researchers, dive community, fishers) are critical to sanctuary management, as they determine the level of success of resource protection, education, research and enforcement programs.

Source of Information

Long Term Monitoring Reports MMS 92-0006 and 96-0046, available from the Minerals Management Service.

Regulations 15 CFR Part 922, Federal Register Vol. 60 No. 248, Dec. 27, 1995, pp.66875-66897.

Final Environmental Impact Statement/Management Plan191. Available from sanctuary Office.

Maps / Field data NOAA Bathymetric Map MS-1.