Flower Gardens Banks National Marine Sanctuary
Coral Reefs in the Gulf of Mexico Play Vital Role But Face Threats
Jul 14, 2009
The Flower Gardens Banks National Marine Sanctuary contains three separate coral reefs. The 100-acre West Bank and 250-acre East Bank contain some 21 species of coral growing between 60 and 100 feet beneath the surface atop salt domes on the floor of the Gulf of Mexico, 100 miles from shore and surrounded by water up to 450 feet deep. The Stetson Bank lies 30 miles closer to shore, a 1,500-foot long ridge of pinnacles covered in fire coral and sponges.
Health of the Reef Ecosystem
This reef ecosystem plays a vital role in the health of the entire Gulf, according to Emma Hickerson, research coordinator for the Flower Gardens Banks National Marine Sanctuary, providing habitat, protection and food for a vast community of marine life including roughly 280 species of fish, 20 of sharks and rays, and sea turtles, marine mammals, and birds. The Flower Gardens remain a healthy, well-populated marine environment, thanks primarily to remoteness and a location farther north than most reefs, where cooler water provides protection from common coral diseases. However, the sanctuary lies near oil and gas operations and shipping lanes, and outflow from the Mississippi River basin, which carries runoff from cities, industry, and agricultural operations in roughly two-thirds of the United States. Increasing levels of many chemicals from that drainage have created algae blooms that in turn lead to an oxygen-deprived dead zone in the Gulf.
Jack Sobel, Ocean Conservancy senior scientist, says the principal threats to coral are climate change, pollution, and fishing. Even slight changes in water temperature can stress coral, and cause the polyps to bleach, or expel their symbiotic photosynthetic algae, which usually results in death of the coral. In 2005, a bleaching event due to slightly elevated temperatures affected up to 45 percent of coral in the Sanctuary, Hickerson reports.
Some 3,000 recreational scuba divers visit the sanctuary each year, introducing the potential for damage from boat engine and generator noise, light from underwater photography, and the introduction of pathogens from other dive sites carried on diving equipment such as wet suits. Coral reefs in other parts of the world have suffered ill effects from increased recreational use.
Protecting the Reefs
The Flower Gardens Banks is one of 14 underwater areas protected by the National Oceanic and Atmospheric Administration’s National Marine Sanctuary Act. Regulations prohibit taking or injuring coral or coral reef organisms, discharging pollutants, or disturbing the sea floor in the sanctuary. Oil and gas exploration and development are prohibited in "no activity" zones, but these do not include all of the sanctuary. Anchoring is also prohibited, as one boat anchor can destroy thousands of years of reef growth. Spearfishing and trawling are prohibited, but conventional hook-and-line fishing is still allowed.
Additional restrictions are needed, Sobel says, including prohibiting the taking of anything from the area, and areas surrounding the sanctuary need protection as well. The sanctuary staff is developing a list of nominated sites to be considered for inclusion.
Recreational users of reef areas can help by supporting reef-friendly businesses, hiring local guides, and never touching coral or anchoring on a reef. Anyone can help by ensuring that sewage from boats and homes is properly treated, avoiding use of pesticides and fertilizers (important anywhere since all land drains, eventually, to the ocean), buying marine life for aquariums only from reputable suppliers, recycling, and conserving water.
Visiting the Coral Reefs at the Flower Gardens
A number of scuba shops organize dive trips to the Flower Gardens on live-aboard dive boats out of Freeport, near Houston, and Lake Charles, Louisiana. Links to these providers can be found on the Sanctuary website. Due to the distance from shore, currents, waves, and other conditions, the Flower Gardens should be considered an advanced dive and not for beginners. Popular times to visit are spring, when hammerhead sharks congregate at the reefs, and late summer, when the reefs are the site of a mass spawning.
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