From Envirowiki

Corals are tiny animals that excrete a calcium skeleton and live in colonies. When you see pictures of coral reefs you are actually looking at hundreds of tiny animals living in a colony. They get their food by the Zooxanthellae algae that live symbiotically with them.

Corals are very important to their habitats because the polyps filter the water by collecting particles. They also provide niches for fish and mollusks.

Contents 1 Bleaching process 2 stressors 3 implications of bleaching 4 References

[edit] 1 Bleaching process

Bleaching occurs when the animals become stressed and the critical balance that maintains their symbiotic relationship with the algae that inhabit their cells is lost^[1]. Once this happens the coral loses a main source of nutrition and dies. The reason it is called bleaching is because that same algae gives the coral its pigment.

[edit] 2 stressors

There are a variety of different stressors that can affect this balance such as overcrowding, heavy sedimentation, an abundance of algae, or increased water temperature. Corals can get stressed very quickly when the temperature changes too drastically. Within the span of a couple weeks a colony can go from thriving to desolate. Stress factor is relevant to global climate change because if the Earth’s water temperatures begin changing then these fragile organisms will not be able to survive in their previous habitat and, because they do not have a great amount of mobility if they do leave the colony based on stress, the chance of mass mortality is extremely high.

[edit] 3 implications of bleaching

This has implications for the status of the animal as well as for the ecosystem as a whole. This could also have implications for countries whose economies depend on the revenue that comes from the eco-services that the coral reefs provide. Because of this policy makers should recommend not only to save their reefs by eliminating immediate threats to the corals such as invasive species and human disruption. They should also take into account how the fossil fuels that they burn heat the atmosphere and ultimately harms the fragile ecosystem.

[edit] 4 References

1. ↑ Reaser, J., Pomerance, R., Thomas, P. Coral bleaching and Global Climate Change: Scientific Findings and Policy Recommendations. Conservation Biology. October 2000.