Related to sea anemones and jelly fish, corals are animals. They flourish in tropical ocean habitats, such as the Caribbean Ocean. Single-celled algae make their homes inside of the coral, providing it with food. This type of relationship is called symbiosis. According to NC State University Agriculture & Life Sciences, symbiosis is "an ecological relationship between individuals of two (or more) different species. Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits." Each coral animal is a tiny polyp. It is a primitive animal made up of a stomach with a tentacle-bearing mouth on top. It secretes a calcium carbonate exoskeleton. Using their tentacles to sting and consume plankton and small creatures, these small animals build the coral reef.
In the Caribbean coral reefs the dominant species of corals are staghorn and elkhorn corals. According to research done by scientists at the Natural History Museum, staghorn and elkhorn corals have survived past environmental crises that threatened coral reefs as far back as 1.5 million years ago. They are fast-growing and can withstand environmental changes such as hurricanes and quick changes in sea level.
Scientists believe coral reefs to be some of the most diverse ecosystems in the world. According to the Defenders of Wildlife website, coral reefs cover 0.2 percent of the world's oceans, but they provide habitats for 25 percent of the planet's marine fish species.
Though there are natural causes that threaten coral reef survival, human behavior has a greater and more devastating impact. Over-fishing throws off the delicate balance of species in the coral reef ecosystem. Pollution has an adverse effect on coral reefs, especially agricultural and land development run-off. This type of pollution often causes an increase in algae growth. Other pollutants such as herbicides, pesticides and human waste affect the health of coral reefs globally.
Natural History Museum's paleontologist (fossil expert) Ken Johnson has studied coral reef fossils and determined that resiliency of corals such as staghorn and elkhorn 1.5 million years ago during environmental changes allowed for the survival of today's coral reefs. He believes that the more we protect our coral reefs from human impact the greater chance they have for surviving the current and predicted global changes. "This insight from the fossil record shows how conserving biodiversity on living reefs can increase their resilience during the coming decades of rapid global-environmental-change," states Johnson. Organizations such as Caribbean Area Coral Reef Initiative, Sustainable Ecosystems Institute and Caribbean Coral Reef Institute are conducting research and monitoring protection of coral reefs. Some of these activities include reducing pollution and over-fishing and creating protected areas to conserve coral reef habitats.
