On March 28, when the Pacific nation of Kiribati created the world's third largest marine wildlife sanctuary, it wasn't just a triumph of conservation, it was an expression of one man's passion. Greg Stone, Ph.D., 49, a biologist and a vice president of Boston's New England Aquarium, first saw Kiribati's far-flung Phoenix Islands in 2000. He could scarcely believe his eyes: eight virtually uninhabited atolls—and, Stone says, "Nobody had ever looked under the water." Fifteen hundred dives later, he had identified several new species of fish and one new species of coral, and he was convinced that the area was an ecological jewel of international proportions. In a one-man campaign, working alternately as scientist, diplomat, and fund-raiser, Stone persuaded the Kiribati government of the same. The result is his crowning achievement, the 73,800-square-mile (191,141-square-kilometer) Phoenix Islands Protected Area.