Papahānaumokuākea

Coral Atoll

Coral atolls form when corals grow in a ring around a high volcanic island in tropical and subtropical seas. Over the years, as the volcano erodes and sinks beneath the surface, a lagoon is formed in the middle and the corals continue to grow in a ring around the lagoon. Several coral atolls are found in the Northwestern Hawaiian Islands, including the Pearl and Hermes (Manawai), Midway (Kuaihelani), and Kure (Hōlanikū) atolls in the waters of Papahānaumokuākea Marine National Monument. Hawaiian atolls are a haven for reef fish, a feeding ground for pelagic fish and sharks, and also provide breeding and nesting grounds for monk seals and sea turtles.