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Coral Reef Rescue

Spanish Translation

By Kathryn Satterfield

Beneath the ocean's surface, a vibrant world encircles the globe. Striped and spotted fish swim through brightly colored formations called coral reefs. "It's just a riot of movement and color," Rod Salm, a marine ecologist with The Nature Conservancy (TNC), told TFK.

But time is running out for these underwater treasures. Last month, at the National Oceanic and Atmospheric Administration's (NOAA) coral-reef meeting, researchers warned that 60% of the world's coral could die within the next 25 years. About 27% of the living underwater cities have already been lost.

Though some coral formations resemble lifeless stone, coral is made up of tiny animals called coral polyps. They grow and divide to build coral colonies. When corals die, their skeletons are left behind. New corals grow on top, forming elaborate reefs. The complex reef ecosystem covers less than 1% of the ocean floor, yet supports about 25% of all marine life. An ecosystem is a partnership between living things and their environment.

The destruction of coral reefs puts many species at risk of extinction. Some researchers say that at least 1 million species of plants and animals live in the world's reefs. On October 29, scientists said they had discovered new reef species in the waters off Hawaii.

REEFS IN HOT WATER
What is killing these coral communities? Irresponsible fishing practices and pollution have taken a toll. Local governments have created protected marine areas to help manage these problems. But rising ocean temperatures are harder to address.

Water that is warmer than normal can cause deadly coral bleaching. Coral contains tiny algae, which are plant-like organisms. They give coral its vibrant color. Coral uses the algae to create food and grow. At high temperatures, corals get stressed and release the algae. Without the algae, coral loses its color and starves. The weakened coral becomes more sensitive to sunlight and disease. Last year, warming in the Caribbean Sea bleached more than 90% of the coral on many reefs.

WORKING FOR A CORAL COMEBACK
TNC scientist Salm has been observing bleaching events for more than 20 years. He noticed that within bleached reefs, healthy patches of coral remained. Salm's observations led to a new conservation strategy to focus on saving reefs that have resilient coral. Corals that are resilient are able to absorb shocks and bounce back. Some coral species have genetic features that help them survive. Scientists are working to identify these factors. In addition, some reefs are better positioned for survival.

Salm has identified several environmental factors that help coral resist bleaching events. For example, reefs are better off if they are washed by currents that cool temperatures by mixing deep, cold water with warmer surface water. A reef's ability to recover is also helped by the diversity of its species of coral and fish. The Coral Triangle is a rich region that holds 75% of all known coral species and 3,000 species of fish. It is at the center of TNC's efforts to create a healthy network of reefs around the globe. If resilient reefs are allowed to flourish, they can help repopulate coral communities nearby. "We need to work with nature to create conditions that enhance recovery," Salm says. The situation, says NOAA's Mark Eakin, "is far from hopeless."

Next: A Voyage to the Past