The world’s coral reefs covers only about 368,000 square miles occupying less than three tenths of one percent of the ocean’s floor. Although the ecosystem is a small one, close to one million species of fish, crabs, eels, molluscs, sponges, worms, algae, grasses and other marine life call the coral reefs their home. But the coral reefs are depleting. There are many factors that contribute to the depletion of coral reefs. They are coral mining, climate, diseases, tourism, blast fishing, farm runoff, sewage, oil and industrial pollution.
Vacationers feel privileged to be able to deep sea dive and get a firsthand look at the incredible biodiversity that the reefs provide. They are unaware of the fact that just by touching the fragile coral, as shown in the photograph; they are damaging its delicate tissue. The coral reefs provide homes for many varieties of plant and animals. Many different kinds of fish live in the reefs as their haven for feeding, reproduction, and safety from predators. Without an ecosystem to live in, these fish species will become extinct.
Ten percent of the world's reefs have been completely destroyed. Coral reef destruction is the worst, over 70% have been destroyed and only 5% can be said to be in good condition. What has happened to destroy so many reefs? Human population has become very large, and earth is warming.
There are two different ways in which humans have contributed to the degradation of the Earth's coral reefs, indirectly and directly. Indirectly, we have destroyed their environment. The large population centres near coasts has led to silting of reefs, pollution by nutrients that lead to algal growth that smothers the coral, and overfishing that has led to increase in number of predators that eat corals.
Warming of the ocean causes corals to sicken and die. Even a rise of one degree in the average water temperature can hurt the coral. The most obvious sign that coral is sick is coral bleaching. That is when...