Two years ago, diver Michael Aw was monitoring the health of local coral some 1,000 miles south of Bombay. Because this major tourist site in the Republic of Maldives is protected from most fishing, "what I least expected to see was a dying, finned shark," he says. Someone had hauled in the 6-foot gray reef shark, sliced off all its fins, and then tossed it overboard. To cover up the act, the plunderer had tied a 15-pound piece of coral to what remained of the tail to ensure the carcass would sink.