Coral Reefs on a Changing Planet

A coral reef is like an underwater city. Corals and algae make the mounds of the reef on the tropical ocean floor. The reef attracts many other creatures who find a home there. Schools of red, blue, yellow, and green fish swim above the reef. Crabs dart around on its surface. And clams nestle into cracks in the rock. All that life needs the reef to survive.

But reefs are threatened by humans in many ways. Some of the threats are easy to see like trash littering a reef, sand in the water or on the corals, and water pollution. Too much fishing is reducing the number of fish that eat algae in some reefs. And there are scratches on corals from the fins of careless snorkelers, anchors, or from boats.

There are also threats that are invisible. We can’t see them, but they are very dangerous for coral reefs. These threats include acidic seawater, warmer seawater, and coral diseases. The threats might be hard to see, but their effects are not. Some reefs have been so hard hit that scientists say they will not be able to recover. Scientists predict that over half of the world’s coral reefs may die by 2050 if these threats continue.

Last modified February 24, 2011 by Jennifer Bergman.

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