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Disappearing Opportunities Coral Reefs: the Tropical Rainforests of the Sea Coral reefs are often called the "tropical rainforests of the sea" for their astounding richness of life. Due to their structural complexity, corals are one of the most productive ecosystems on Earth, providing important services to mankind including fisheries, coastal protection, medicines, recreation, and tourism. Corals are tiny animals that live in colonies and derive nourishment and energy from a symbiotic relationship with zooxanthellae algae. Coral reefs are formed over the course of thousands of years as limestone skeletons constructed by corals accumulate and form a structural base for living corals. Scientists estimate reefs provide a home for millions of species - from brightly colored tropical fish to sea cucumbers which produce anti-cancer compounds. Like tropical rainforests, coral reefs are imperilled by human influences. Coral reefs are particularly fragile ecosystems, partly due to their sensitivity to water temperature. When corals are physiologically stressed - as is the case when water temperatures are elevated - they may lose much of the their symbiotic algae, an event known as "bleaching." Corals can recover from short-term bleaching, but prolonged bleaching can cause irreversible damage. In 1998, when tropical sea surface temperatures were the highest in recorded history, coral reefs around the world suffered the most severe bleaching on record. 2002 was even worse: nearly 60% of the 135,000 square mile Great Barrier Reef suffered some bleaching. It is estimated that even under the best of conditions, many of these coral reef ecosystems will need decades to recover. Although reefs face other threats from pollution, industrial activities, overfishing, siltation, cyanide and dynamite fishing, and anchors, it is global climate change that most concerns scientists. Coral reef pictures (Heron Island, Australia 1) (Heron Island, Australia 2) |
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Consequences of Deforestation |
Local Climate Regulation Loss of Species, Disease Climactic Role Extinction |
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