Coral Sea

A marginal sea of the South Pacific off Australia's northeast coast, covering about 4.8 million square kilometers and hosting the world's largest reef system, the Great Barrier Reef, alongside over 1,500 fish species, 400 coral species, six species of sea turtle, humpback whales and dugongs. Mass coral spawning drives reef reproduction, the East Australian Current cycles nutrients through the system, and crown-of-thorns starfish periodically prey on coral in numbers that can strip whole reef sections. Coral bleaching from warming water, shipping accidents, oil spills, coastal runoff and cyclones threaten the sea, part of which is now protected within the 989,836 square kilometer Coral Sea Marine Park established in 2017.