Endangered Coral Reef Ecosystem

¶ … endangered coral reef ecosystem. Coral reefs, when they are healthy, are one of the most diverse ecosystems on the planet. They contain so much life and interaction many scientists call them the "rainforests of the seas." Yet these reefs are endangered around the world, and their ecosystems are changing because of pollution, mismanagement of the natural resources, and the influence of man on the fragile environments of the coral reefs.

Coral reefs are found in most tropical zones around Earth. They can only survive in certain conditions, for example, they must have an annual water temperature of at least 74 degrees Fahrenheit, and they typically do best in shallow water, where sunlight can reach and photosynthesize the plants (Ekman 4-6). The sun is the major source of energy for these ecosystems, it provides energy for plankton, plants, and algae to survive, and these are all necessary foods for the many animals that live in the coral reefs. In addition to sunshine, reefs are quite efficient in recycling the nutrients around them. Another scientist notes, "Coral reefs house the bulk of known marine biological diversity on the planet, yet they occur in relatively nutrient-poor waters of the tropics. Nutrient cycling is very efficient on reefs, and complicated predator-prey interactions maintain diversity and productivity" (Agardy). Healthy reefs are efficient and abundant life sources. Fish, shellfish, plants, and a wide variety of animals make their home among the coral outcroppings of the reefs. Sponges, the corals themselves, sea urchins, a variety of worms, starfish, shrimps, crabs, lobsters, octopuses, squids, clams, scallops, marine snails, nudibranchs, and dozens of varieties of small and large fish are just some of the many animals that make their home on the reef. However, if the balance between these animals is altered, then the reef itself can suffer, and eventually die, and that is what is happening to the delicate ecosystems of reefs all over the world. Their balance is being changed by a variety of circumstances, and they are dying. Writer Agardy continues, "Some 37% of all corals in Florida have died since 1996, and the incidence of coral disease at sampling sites there went up by 446% in the same short period" (Agardy). Unfortunately coral disease is just one of many facets affecting coral reefs.

Humans are affecting reefs far more rapidly than natural diseases. Some reefs are destroyed due to costal development. Others are overfished, removing one of the vital links in the ecosystem, and so, with the fish gone, the coral reefs change, die, and return to the sea. This is because the fish graze on the algae, keeping it under control. When these grazing fish are removed by too much fishing, the algae can grow out of control and take over the reef itself (Agardy). One of the biggest threats to the coral reefs is runoff of fertilizers and chemicals from homes and businesses into the oceans of the world. These release an overabundance of chemicals into the water, which can ruin coral reefs. Agardy notes, "The overabundance of nutrients causes algae to overgrow and smother coral polyps; in extreme cases, leading to totally altered and biologically impoverished alternate ecosystems" (Agardy). Thus, coral reefs are delicate ecosystems that function quite well when left on their own, but can break down completely when items are added to or removed from the balance nature created.