GARDENERS OF THE SEA
Coral reefs cover less than one percent of the ocean floor, yet they are home to about a quarter of all the species that live in the sea. They matter to people, too. Hundreds of millions of people around the world depend on reefs for the fish they eat, and the reefs act as natural walls that break the force of storm waves before they reach the coast. Sadly, these underwater cities are in serious trouble. In the Caribbean, more than half of the living coral has disappeared since the 1970s. Rising water temperatures are the main cause: when the sea becomes too warm, corals lose the tiny plants that feed them, turn white and often die.(lines 1–7)
About fifteen years ago, a small group of marine scientists decided to give nature a hand. A damaged reef can heal by itself, but most corals grow only a few centimeters a year, far too slowly to make up for the losses. The scientists' answer was the coral nursery: rows of plastic "trees" fixed to the sea floor, with small pieces of coral hanging from their branches. Protected there, the pieces grow quickly. "We never choose them at random," says Dr. Ana Reyes, one of the founders. "We cut them from corals that have lived through the hottest summers, so their young have a better chance."(lines 8–14)
At first, critics called the project far too costly. Every young coral had to be attached to the reef by hand, at a price of about $100 each, and a team of divers could plant only a few hundred in a day. Reyes accepts that the early methods were slow, but she rejects the idea that the money was wasted. What worries her more is how future donations will be spent. "Money for reef projects should go to the people who live beside the reefs," she says. "They will still be there long after we scientists have gone home. If they learn to run the nurseries themselves, the work will go on."(lines 15–21)
New plans in several Caribbean countries now follow this advice. Local men and women are being trained as divers and nursery keepers, and they receive a salary for their work. Organizers hope that the benefits will reach the whole community. With healthier reefs, fishermen could bring home bigger catches, families could earn money by taking tourists snorkeling, and coastal villages would suffer less damage in storms.(lines 22–26)
Early results are encouraging. On some of the first replanted reefs, two thirds of the planted corals were still alive after five years, and a few have begun to produce young of their own, a sign that the reef is coming back to life. Yet Reyes warns against celebrating too soon. "Nurseries can buy us time, but they cannot cool the ocean," she says. Two summers ago, a period of unusually hot water killed many planted corals within weeks. Scientists are now testing ways to shade small areas of reef on the hottest days, but such methods are expensive and work only on a small scale. In the end, Reyes believes, the future of coral depends on slowing climate change.(lines 27–33)