What are corals and coral reefs and why are they important?
Corals are colonies of simple anemone-like animals that take up calcium carbonate from sea water to build limestone skeletons for support. Corals are not just "rock"; their surfaces are covered with living animals. Over many thousands of years, corals, together with other animals and plants, build reefs. The variety of shapes and colors of corals and the myriad of reef fish and other species gives the coral reef unsurpassed beauty and interest that attract millions of tourists around the globe.
But there is more to coral reefs than beauty. Coral reefs supply our white sandy beaches with sand, they form barriers that break the waves and protect our shorelines and property, they provide a home to an enormous diversity of marine plants and animals, they support an important reef fishery and provide food to local people, they are a source of new medicines, and they generate income from tourism.
The reef-building corals are quite particular about the conditions they need to survive and grow. They need clear and clean water, low in nutrients and sediment; they can't cope with much change in the salinity or the temperature of the water, and they need plenty of light because tiny algae (single-celled plants) live inside the coral animals. The algae are essential to the health of the reef, providing some food to the coral and helping to build the skeleton.
If these conditions are not met, the coral will become stressed (don't think that humans are the only species that suffers from stress!) and often react by expelling their algae or shedding tissue. Prolonged stress will result in death. The major man-made threats to coral reefs are coastal development (including land clearing and construction), which causes increased runoff of fresh water and mud; sewage pollution, marine pollution, destructive fishing practices and over-fishing; and physical damage from careless recreational activities.
|We all must and can help to preserve coral reefs. You as an individual can make a difference. The key is to understand and to be aware. And once you are aware, it's simple and easy. For more information on how you can take action to preserve coral reefs: CORAL.