Understanding what’s killing the world’s coral reefs(珊瑚礁) has been the life work of Mark Hay, the Teasley Professor in the School of Biology at the Georgia Institute of Technology. During the past 35 years, he has made more than 5,000 dives in both the Caribbean and Pacific, and each year he spends as much as five months with villagers on the Fiji Islands.

On November 7 he received the Lowell Thomas Award from the New York-based Explorer’s Club. “Dr. Hay’s research and discoveries have influenced the foundations in the field of marine chemical ecology and created new procedures for effective conservation and management of the world’s coral reefs,” the organization said.

Hay notes that over the last 40 years, the world has lost 80% of coral reefs in Caribbean and 50% of the reefs in the Pacific. “For about a billion people around the world in the tropics, coral reefs are one of the major sources of protein, so the loss affects food security for these areas,” he said. “Reefs also provide storm protection for low-lying villages, absorbing big waves coming into shore.”

Hay’s research has focused on the complex interactions between species, communicated by chemical signals emitted by the plants and animals that are part of the reef community. For instance, seaweeds(海藻) harm coral by emitting poisonous chemicals and by mechanically damaging it. Certain fish protect coral by controlling the seaweeds, but overfishing has allowed seaweed to get out of control on many reefs.

Among recent examples, Hay and his partners have learned that degraded reefs produce chemicals that tell baby fish and baby corals to stay away. Unless those signals can somehow be changed, damaged reefs won’t have a chance to recover.

At Georgia Tech, Hay keeps an office and a lab. But the majority of his experiments are conducted outside, on coral reefs, building cages to learn about interactions between plants and animals.