Coral Bleaching Effects

Coral reefs are the most diverse communities in the marine environment. Hermatypic-corals help form the structure of coral reefs and a shelter for a variety of organisms. Living coral reefs form land, provide the sand that lines tropical beaches, and the structures which prevent the waves from causing extensive coastal erosion. However, pollution from sewage and agricultural practices damages corals as well as the wide variety of organisms living within them. Stress is a physiological condition which results from adverse or excessive environmental factors and in corals and can be measured by decreased growth rates, metabolic differences, and biochemical changes. There are varying levels of degradation of coral reefs such as mortality to more sublime changes in

Corals under stress due to changes in PH levels or temperature of the water will expel the algae (zooxanthellae) living within their tissues causing the coral to turn completely white. This is called coral bleaching. Another cause of coral bleaching is produced formation water, an effluent of offshore oil and gas industries that cause significant bleaching ( White et al .2012) .When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality. Mortality amongst corals has appeared to be the breakdown of the symbiotic association between the zooxanthellae and the coral host. In January 2010, cold water temperatures in the Florida Keys caused a coral bleaching event that resulted in some coral death. Researchers discovered that this cold-stress event will make corals more susceptible to disease in the same way that