A green sea turtle (Chelonia mydas) swims over corals off the coast of Maui, Hawaii. Genetically distinct populations of green sea turtles occupy tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans. Adults inhabit shallow waters where they feed on seagrasses, unique among sea turtles. The vegetarian diet gives their fat a greenish color, thus their common name. The Hawaiian population nests at protected beaches of the French Frigate Shoals, about 800 kilometers west of the Hawaiian Islands. After mating underwater, a female crawls onto a beach and buries the fertilized eggs in sand above the high tide line before returning to sea. Clutch sizes are 85-200, and eggs hatch after about 50-70 days. Hatchlings emerge at night in synchrony and instinctively head into the sea. Many are lost to predation by gulls and crabs. A turtle takes several decades to reach sexual maturity, but those that do may live up to 80 years. The IUCN Iists green sea turtles as endangered. They have been hunted for food, and many die from being caught in fishing nets. Real estate development has destroyed nesting sites. Protettive regulations Iaunched in the 1970s have permitted populations to rebound. Most countries now protect the species from exploitation, and nesting areas have been preserved. A long-term survey of Pacific populations indicates that they are now stable or growing in size. The turtles nonetheless remain threatened by pollution, plastic waste that accumulates in our oceans, and degradation of their coral-reef habitats.