Outline the issues concerning the degradation of coral reefs and the ways in which people are responding to these impacts.
Coral reefs have been described as the oceans rainforests, due to the rich diversity of life they can support. However, although the area of tropical warm water that can support reefs is vast, reef communities are becoming increasingly and worryingly rare. The largest reef of all is the Great Barrier Reef, which is 1500 km long, although it actually exists as approximately 2900 separate reefs. There are three main types of reef which are defined by the way they develop. They are fringing reefs, barrier reefs and atolls. Their structures are never the same but they share distinctive general structures. Fringing reefs are found close to shore and are separated from land by only a shallow stretch of water. Barrier reefs lie further offshore and are separated from land by large lagoons of up to 10 metres deep. Atolls form far offshore in a ring shape around circular lagoons.
Reefs are valuable resources for countries as well as communities. They are used as a source of food, marine souvenirs (sponge and coral), collecting exotic fish for aquariums and mining coral. Some of these activities are sustainable while others are not. Large-scale removal of coral from reefs can lead to some areas being completely destroyed. This is due to reefs relying on a strict cycling of nutrients that, like any huge biome, is very sensitive to change. Even activities such as diving and reef walking can lead to the disruption and destruction of eco-systems. Surprisingly, coral degradation is affected more by the aforementioned activities than by coastal engineering and coral mining.
Different parts of coral reefs will experience different environments, dependent on depth and force of the water, therefore zonation often occurs. However, the distribution of species along a coral reef is more affected by interspecific competition.