Just a few years ago, scientists sounded the alarm that coral reefs around the world were seriously ailing. But now, some coral reef biologists are beginning to suspect that reefs may not be quite as widely imperiled as they once thought. Increasingly, researchers think that the decline may be local or regional rather than global in scope. Although reefs in Southeast Asia and the Caribbean are crumbling, for instance, most in the Pacific and Indian Ocean appear to be in good health.