Coral reefs are a vital part of an ecosystem. They represent the skeletons of algae and corals solidified into calcium carbonate. There are several different types of reef, including apron, fringing and table, depending on their relationship to the shore. In terms of the ecosystem, coral reefs support a huge amount of sea life by recycling nutrients in nutrient-low parts of the ocean, therefore providing life and health for the surrounding sealife, while also feeding off it to produce new reef formations. They also represent homes for various types of tropical fish, and other sea organisms, such as lobsters and sea turtles. Pollution and the live food fish have developed into serious threats to the delicate ecosystem balance that the coral reef inhabits. For example, if a forest is destroyed during coastal construction, the run-off of nutrients can saturate the waters and suffocate organisms adapted to a low nutrient environment. Similarly, excessive fishing, most notably using cyanide, destroys the structure of the reef and the organisms it depends on to sustain itself.
