Amazing colors and shapes and thousands of fishes make coral reefs one of the most spectacular underwater places for people to visit. Each reef is completely unique in its shape and the kinds of animals that call it home. A great number of plants and animals that live in coral reefs have not been studied, or even named, yet. Some of the ones we are studying may give us new medicines to treat cancer, protection from too much sunlight and antibiotics to fight infections.

Environmental Concerns

Erosion does not affect coral directly, but silt, mud, fertilizers and herbicides that wash off the surrounding land damage delicate coral reefs. Silt and mud cover the corals with a cloud of haze, and herbicides kill not only the algae that live within coral polyps, but plant life all over a reef. Fertilizers and untreated sewage provide an excess of nutrients where certain types of algae will grow faster than they normally would.

CLOWN FISH

The overgrown algae choke the coral reefs and attract predators, such as sea urchins and crown-of-thorn starfish, which destroy living coral. A major problem in coral reefs around the world is coral bleaching. Algae that live inside the polyps and gives them their brilliant colors is killed or ejected. When this happens, an entire coral reef can turn white. Scientists are still not sure exactly what causes this to happen. One theory suggests that coral bleaching is the result of higher than normal water temperatures.

Oil Tanker Spill

Humans have done a great deal of damage to coral reefs around the world. Oil spills and pollution suffocate living corals and poison the waters. It can take many years for a reef community to recover from the damage a single oil spill can do. Tourism is another area where human impact has been harmful to reefs. To attract tourists, some islanders have blasted boat channels through reefs. Divers and snorklers damage or break fragile coral branches by simply touching them or grazing them with a careless hand or flipper. Dive boat operators and fishermen destroy reefs with anchors and propeller blades. Souvenir-seeking tourists snag pieces of coral, which took the reef years to build.