SECRET REEF. The Flower Garden Banks National Marine Sanctuary

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Beverly Casey
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1 SECRET REEF The Flower Garden Banks National Marine Sanctuary

2 The Flower Garden Banks National Marine Sanctuary Deep in the waters of the Gulf of Mexico, just 115 miles south of Texas lies a coral reef teeming with life. Known as the Flower Garden Banks National Marine Sanctuary (FGBNMS), this fascinating habitat was first discovered more than 100 years ago by fishermen. The area was named the Flower Garden Banks due to the brightly colored rocks that were often snagged on fishing gear and anchors. These fishermen soon learned that what they had snagged were not rocks, but actually beautiful living organisms called corals. Geologists began to study the area in the 1950s thinking it might harbor corals and other organisms. In the early 1960s the first scuba divers visited the Flower Gardens. These divers consisted of scientists from the Houston Museum of Natural Science along with several volunteers. An enormous coral reef and huge schools of tropical fish, rays, turtles and sharks greeted these first divers. Study began on this fascinating marine ecosystem using divers and submersibles. The scientists discovered the reef extended down over 300 feet deep. They found natural gas seeps, an overflow canyon inhabited by chemosynthetic bacteria and a brine lake. Studies indicated that large volumes of salt were dissolving from beneath the bank. Reviews of these studies concluded that the banks developed from salt plugs pushing up the sediment over them to form vast underwater mountains. The formation of these salt domes began over 150 million years ago when salt layers were deposited by evaporation in what was once a shallow sea. Over the years, these layers grew and the internal pressures pushed up the salt into distinct domes. Coral formations began to grow on these domes about 15,000 years ago. The closest coral reefs to the Flower Gardens are located nearly 400 miles away off Tampico, Mexico. Scientists believe that corals at the Flower Gardens probably originated from the Mexican reefs. Currents in the western Gulf of Mexico brought young corals (planulae), other animal larvae and plant spores northward and they settled on the hard substrate found at the Flower Garden Banks. This location provided all the required elements hard corals need to survive: a hard surface for attachment, clear sunlit water, warm water temperatures, and a steady food supply. Today, over 20 species of corals have been identified at the Banks. Intense descriptive and taxonomic surveys of the banks in the 1970s led to more detailed coral reef studies in the 1980s. These studies began the process that would culminate in this area being designated a National Marine Sanctuary. The 1990s saw the growth of tourism and the arrival of 3,000 recreational divers each year. Mooring buoys were installed in the

3 1990s to help protect the reef from the effects of anchoring. Through the efforts over many years of scientists and recreational divers seeking to protect this area, it was designated as a National Marine Sanctuary in At that time, the sanctuary included the East and West Flower Garden Banks. Stetson Bank, another close reef just 30 miles northwest of the banks, was added in The East Bank encompasses 247 acres of coral reef while the West Bank encompasses 98 acres. Stetson Bank is somewhat smaller comprising 59 acres. The Flower Garden Banks boasts the northernmost living coral reef in the United States. The coral cover at the Banks is the highest of most of the world s coral reefs at an amazing 50%. Giant star and brain The Flower Garden Banks National Marine Sanctuary protects an area 42 square nautical miles or over 31,000 acres. coral heads may grow to the size of small cars. Nearly 20 species of corals have been identified along with 257 species of fish. The Flower Garden Banks is currently considered to be a healthy reef even though this area is subject to the tolerance extremes for reef-building corals. The FGB are some of the most pristine reefs in the region. They exist in an area of good water clarity and appropriate temperature and salinity levels that help promote coral growth. Studies have shown that the coral cover has not changed much since Occasional coral bleaching is observed but is not considered to be significant. The level of diversity of fish species is a bit lower than Caribbean reefs, but the species exhibit good health overall. Many other life forms exist on the Banks including sponges, crustaceans, aquatic worms, mollusks, sea stars, sea turtles and sharks. The Banks also serve as a habitat for the colossal whale shark, the largest species of shark in the world as well as the giant manta ray. In the winter, schools of hundreds of hammerhead sharks migrate through the FGB. Hawksbill, leatherback and loggerhead sea turtles along with the Atlantic spotted dolphin and bottlenose dolphins can also be seen along the Banks. The Gulf of Mexico is a valuable resource not only for its biological diversity but also for the oil and natural gas present beneath the sea floor. These industries produce one quarter of the natural gas and one-eighth of the oil for the United States respectively. The Mexican petroleum industry produced over 2,500 million barrels of oil and 433 million barrels of natural gas daily in The Gulf fishery industry is also some of the most productive in the world currently. In 2000, the combined total for fish and shellfish harvest equaled 1.7 billion pounds. The commercial fishing industry generated over $900 million in revenue in 2000.

4 All of these industries must work together in order to ensure that this habitat remains productive. For more information on this topic read about the Minerals Management Service, National Marine Fisheries Service and the Resource Database for Gulf of Mexico Research. As a National Marine Sanctuary, under the management of NOAA (National Oceanic and Atmospheric Administration), this area is protected while still being available for scientific, commercial and education activities. The FGB is one of 13 marine sanctuaries that are managed by NOAA. The mission of the FGBNMS is to conserve, protect and enhance the biodiversity, ecological integrity and cultural legacy of the Flower Gardens and Stetson Bank for current and future generations. Management of the Flower Garden Banks is critical as it is located in one of the most productive oil and gas fields in the world. The Sanctuary staff has developed partnerships with other governmental agencies, dive groups, private non-profit organizations, the oil and gas industry, public school and universities in order to work together to promote conservation while still allowing activities such as fishing and oil and gas exploration. The United States Coast Guard plays a role in the health of the Flower Gardens through monthly monitoring of illegal fishing activities and anchoring vessels. They also monitor the recreational use of the area. Although the location of the Banks helps to buffer them from some human pressures, there are still threats to the reef that must be managed. These threats include damage caused by anchoring, impacts from fishing, potential water quality decline and impacts from the oil and gas industry. By maintaining positive working relationships with other organizations, the Sanctuary is more efficiently managed and regulated. National Marine Sanctuaries Flower Garden Banks Olympic Coast Cordell Bank Gulf of the Farallones Monterey Bay Channel Islands Hawaiian Islands Humpback Whale Fagatele Bay Thunder Bay Stellwagen Bank USS Monitor Gray s Reef Florida Keyes

5 PROTECTING THE REEF There are many things that we can do to help maintain the good health of this important ecosystem. Divers and fishermen that visit the area can ensure that they do not damage the reef by disturbing the corals or animals, preventing waste and trash from entering the water and using caution with their fishing equipment. However, you don t have to visit the FGBNMS to help. All of us that live inland can help conserve this natural resource by managing our runoff of fertilizers or pesticides and reducing the amount of chemicals we use. Runoff from our area enters the water system here in Tennessee and ultimately drains into the Gulf of Mexico. In fact, nearly twothirds of the United States drains into the Gulf of Mexico bringing nearly 280 trillion gallons of freshwater to the Gulf. By reducing our runoff, leakage and emissions from our households and automobiles we can contribute to the good health of the Gulf. In a time when the world s coral reefs are dying at a frightening rate, the Flower Garden Banks remains in excellent condition. The protection it receives as a Marine Sanctuary and through support from industry, scientists, divers and the community, will allow us to continue to enjoy this amazing ecosystem for years to come. For more information on the Flower Garden Banks and other National Marine Sanctuaries visit NOAA s National Ocean Service web site at

6 CORAL REEFS Coral reefs provide habitat for numerous fish and invertebrate species. They act as an early indicator for hazards that are caused by both natural and human events and they protect shorelines from erosion. They also positively impact tourism by creating areas for bountiful fishing and recreational activities. Coral can be divided into two basic categories: hard corals and soft corals. Hard corals have cup-like skeletons that form the foundation of coral reefs. Soft corals have bits of calcium carbonate scattered throughout their bodies. Coral reefs are made up of colonies of individual invertebrate animals called polyps that all live together in a limestone skeleton structure. Each polyp is soft-bodied and resembles an upside-down jellyfish. Corals have a symbiotic relationship with algae living inside their tissue known as zooxanthellae. In this relationship, corals provide the algae a protected environment in which to live and the elements necessary for the algae to carry out photosynthesis. In return, 90% of the coral s food source comes from the sugars and other compounds made by the zooxanthellae. The other 10% of their nutrition comes from extending a circle of tentacles, to capture plankton. Coral gets its color from the algae or zooxanthellae living deep within the polyp s tissue. If the coral were to become stressed, it would expel the zooxanthellae, and the colony would take on a white appearance known as coral bleaching. Corals hunt by extending their tentacles and capturing plankton. Plankton are microscopic plants and animals which drift in the oceans currents. Corals feed at night because they are less likely to fall victim to predators. During the day coral polyps pull in their tentacles and hide deep within their limestone skeletons. Corals exhibit a wide variety of shapes including branching, elkhorn, mushroom and digitate (finger-like). Factors that affect a colony s shape outside normal growth patterns are: (1) where the coral lives (2) wave action, light and temperature (3) how closely corals live to each other. Corals reproduce either sexually or asexually. Sexual reproduction in coral is also called spawning. Eggs and sperm are released into the water where fertilization occurs. The result is a coral larvae or planula. Each summer, corals at the Flower Garden Banks spawn 8-10 nights after a full moon sometime between 9:00 p.m. and midnight during the months of August and September. This is what is known as a mass spawning event. Each coral species spawn on a different night to ensure that no hybridization occurs. Once the larval coral or planula is formed, it floats on the surface of the water for several days or even weeks until it finds a suitable hard surface on which to attach and begin growing. Spawning Planula floating Planula Settling on hard surface

Branching coral colonies can grow as much as 3.97 inches vertically each year. Other corals, such as massive corals, typically grow only 1/8 3/4 inch per year.

They then count the annual growth rings similar to counting the growth rings of a tree. Coral reefs are one of the oldest known ecosystems on Earth.

Asexual reproduction occurs when a coral polyp clones itself by forming a new bud next to the parent polyp.

7 Branching coral colonies can grow as much as 3.97 inches vertically each year. Other corals, such as massive corals, typically grow only 1/8 3/4 inch per year. As branching corals become larger, taller and heavier, they become increasingly unstable and may break off in strong waves. Scientists can determine the age of a colony by x- raying a core sample. They then count the annual growth rings similar to counting the growth rings of a tree. Coral reefs are one of the oldest known ecosystems on Earth. The reefs off the Big Island in Hawaii date from 15, ,000 years ago. (Monterey Bay Aquarium Research Institute). Asexual reproduction occurs when a coral polyp clones itself by forming a new bud next to the parent polyp. The newly formed polyp is an exact copy of the parent polyp and will remain forever attached to its parent. The future of coral reefs is uncertain. Current estimates note that 10% of all coral reefs are degraded beyond recovery. Thirty percent of reefs are in critical condition and may die within 10 to 20 years. Experts predict that if current pressures are allowed to continue unabated, 60% of the world s coral reefs may die completely by (CRTF, 2000). The ideas below are ways that you personally can help protect coral reefs. Do not buy saltwater tropical fish or other live reef animals, including coral, for a home aquarium unless you are sure they were collected in a sustainable way. Do not buy dead and dried marine souvenirs such as coral, pufferfish or seahorses. Do not feed or touch marine animals. It disrupts their normal feeding and mating behavior patterns and may introduce disease or aggressiveness. Participate in a coastal or underwater cleanup such as the Tennessee River Rescue. Make sure trash always goes in the proper container. Be a responsible diver, boater and snorkeler. Be responsible at home by making sure your car does not leak oil and using caution when applying pesticides or other chemicals to your lawn. Try to conserve energy whenever possible in order to reduce global climate change. Take public transportation, walk, or ride a bike whenever possible. Support marine sanctuaries.

Ocean Series Coral Reefs

Ocean Series Coral Reefs Coral is part of the animal kingdom, a member of the scientific phylum Cnidaria along with other marine creatures including sea jellies. Sea jellies have a soft gelatinous body