Coral Reefs

In certain places, such as the Maldives and other islands in the Indian Ocean, entire reef systems were destroyed. This problem was observed in at least 60 countries and island nations, only the central Pacific region was spared. The rise in water temperatures is a direct result of the now famous greenhouse effect, where levels of gaseous pollution from the burning of coal, oil and gas are increasing the global temperatures to record levels. Experiments (Littler and Littler 1995) have shown that once the water temperature reaches a constant 32 degrees Celsius, the corals bleach. Corals are only capable of living in a very narrow temperature range, between 25 and 29 degrees Celsius, hence the rise in water temperatures in the areas that the coral have been growing (some as long as 2.5 million years (Guilcher 1988) are beginning to bleach the corals. New evidence suggests that over time the bleached corals can regain their color and have a potential for regrowth, however if the bleaching occurs too often, the corals die off. Another major problem with the bleaching is that the polyps become more susceptible to other threats such as pesticides and pollution. .
             Humans are cutting down more trees, building more roads, and developing more then ever. As development continues to alter the environment, the amount of freshwater runoff increases. Along with other problems this runoff often carries large deposits of sediment, often very rich in nutrients from large agricultural areas. This sediment will blanket the water, decreasing the amount of sunlight that is able to penetrate to the heads of the coral, thus causing a bleaching of the coral, slowly killing it. Yet, this is not the only way in which erosion will harm the coral reefs. Just as high levels of nutrients cause large algae blooms in freshwater ponds, the nutrients in the eroded soil will enhance the growth of other organisms that will out compete the slow growing coral, organisms such as sponges and soft corals.