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The Year Of The Reef

The islands of the Caribbean Sea are famous for their jewel-like beauty. And their brilliant colors don't end where the bright blue water meets the sparkling white sand. Some of the most amazing scenes in nature lie nearby, underwater: crayon-colored coral reefs.

But coral reefs everywhere are in danger of dying. Up to 60% may be destroyed in the next 20 to 50 years if the reefs are not protected. Overfishing, pollution and other problems have already mortally wounded 10% of the world's reefs.

"You can never point to just one thing and say it's this that's killing the reefs," says biologist Clive Wilkinson at the Australian Institute of Marine Science. "It's almost everything."

Worried environmentalists and marine scientists have declared 1997 the International Year of the Reef. They have organized a huge project to educate people about how to protect our precious coral reefs.

Cities Beneath The Sea
Coral reefs are built out of colonies of see-through animals called corals-- cousins of jellyfish. They even sting like jellyfish do. The animals develop a hard outer shell and stick together to build their colonies in distinct shapes. The colonies can resemble a tall tower, a brainlike bundle or a big bouquet of noodles. Only the outermost corals are alive. Coral colonies join to make complex structures called reefs. Mature reefs extend for hundreds of miles and are as much as 7,000 years old!

The brilliant colors of coral come from tiny algae that live inside each coral. These alga plants, called zooxanthellae (zoh-uh-zan-thel-ee), turn sunlight into food, just as plants on land do. Corals use the food. This helpful relationship between the corals and the plants is called symbiosis (sim-by-oh-sis).

Reefs are useful to thousands of species, including humans. They protect shorelines against fierce tropical storms and provide safe harbors for ships. Reefs offer food and hiding places for small fish and hunting grounds for big ones. Parrotfish, spiny lobsters and billowy squid are among the colorful species that depend on these underwater cities.

How Humans Harm These Habitats
"Reefs are tough," says Wilkinson. "You can hammer them with cyclones, and they'll bounce right back. What they can't bounce back from is constant stress."

Fishing too much around a reef can disturb its balance. Without fish to graze on seaweed, a reef can become overgrown with the plants. The overfished reefs around Jamaica in the Caribbean have been smothered in seaweed since 1983.

In the Philippines, fishermen have exploded dynamite in reefs to kill the fish that live there. Divers have used a poison called cyanide to stun fish and catch them. Divers were leaving 163 tons of cyanide underwater each year, which poisoned the coral. The Philippine government has started cracking down on deadly fishing, but some experts believe about 90% of the country's reefs are dead or deteriorating.

Believe it or not, chopping down trees starts a chain reaction that ends up harming faraway coral reefs. When trees are cleared, soil that used to cling to tree roots slides into rivers by the ton. The dirt washes out to sea. Sometimes the soil blocks sunlight from reaching the corals, so they die. Besides soil, rivers bring pollution from distant factories and towns and dump it on reefs.

Coral reefs cannot survive high temperatures. Overheated corals release their color-packing zooxanthellae and turn white, a process scientists call bleaching. Around the Galapagos Islands near Ecuador, a 1983 bleaching outbreak killed 95% of the coral reefs. Scientists fear that global warming, caused by pollution, may raise ocean temperatures to levels dangerous for reefs.

Big Plans For 1997
Next year a group called the Global Coral Reef Monitoring Network will study the health of every coral reef it can find. Educating the people who live near reefs is the key to saving coral, says biologist Wilkinson. Some folks, he says, just don't appreciate how their actions can do damage below sea level: "If we get people to stick their heads underwater, they'll gain a far better appreciation."

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