Coral reefs are home to more kinds of life than any other marine environment, rivalling even the tropical rainforests on land. In fact, coral reefs reached their current level of biodiversity fifty million years ago and have been on the planet for over 400 million years.
The longest coral barrier reef in the world lies off the coast of Australia. The second longest is off Belize and the third longest runs from North Key Largo to the Dry Tortugas in the Florida Keys. Barrier reefs protect coastal areas from storm surge by absorbing the impact of wave and wind action. Coral reefs are also valuable for commercial and sport fishing, tourism and recreational opportunities for diving, boating, and photography as well as their intrinsic value as a natural wilderness that provides habitat for numerous species, some of them endangered.
The coral reef ecosystem is a complex, interdependent ecosystem consisting of coral reefs, mangroves and seagrass beds. Each of these communities plays an important role in the life and health of the reef, from providing nurseries for young reef creatures to filtering water and trapping sediments. The delicate marine environment of the reef itself relies upon the interaction of many different forms of life: hard and soft corals, algae, fish, sponges, crustaceans, worms, turtles, dolphins and other sealife.
The massive boulder and branching corals at the reef form the basis of a coral reef community. They are composed of thin plates or layers of calcium carbonate secreted over thousands of years by billions of tiny, soft-bodied animals called coral polyps. The reef is constantly growing new colonies of polyps on top of the skeletons of older ones. Corals typically grow only one-half inch per year. Soft corals such as sea whips and sea fans lack the rigid exoskeleton of the hard corals and they sway in the ocean currents, but are comprised of living animals as well.
Coral Is Extremely Fragile
Coral, for all its sturdy appearance, is extremely fragile. The lightest touch with fins, hands or equipment can crush or destroy the living coral polyps, leaving the coral vulnerable to disease and bleaching. An individual coral polyp resembles a tiny sea anemone and contains within its body tissue minute symbiotic algae, known as zooxanthellae, which gives the coral its color. Coral bleaching occurs when stressful conditions occur and the zooxanthellae leave the host coral and the coral then appears white, or colorless. The coralhead can recover if conditions return to normal within a few weeks and the zooxanthellae return to populate the host coralhead.
Florida's Reef Tract is the Only Living Barrier Reef System in North America.
Florida's reef tract is composed of outer barrier reefs and patch reefs and is the only living barrier reef system in North America. The reefs of the Keys are typically "spur and groove" formations - a series of ridges and channels found in shallow waters. Because of these ideal conditions, the Florida Keys hosts several million snorkelers, divers, fishermen and boaters every year. It is the number one dive destination in the world.
Coral reefs need clear, clean, nutrient free waters to thrive. Florida's delicate coral reefs are literally being destroyed by cumulative impacts-from declining water quality from agricultural runoff from Florida Bay and inadequate sewage and stormwater treatment in the Keys, to physical impacts from accidental boat groundings, anchors, marine debris, fishing gear and even the careless touch of a diver or snorkeler. Add to that the global impact of sea temperature change and ocean acidification and you can understand why it's said "We are loving our reefs to death."
If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering. Aldo Leopold, Round River, 1993.