Tern Island is a tiny coral island located in the French Frigate Shoals in the Northwestern Hawaiian Islands, at 23.870°N 166.284°WCoordinates: 23.870°N 166.284°W, approximately 490 miles (790 kilometres) west north west of Oahu. It has a land area of 105,276 m2 (26.014 acres). The island provides a breeding habitat to millions of nesting seabirds, threatened Hawaiian green sea turtles, and endangered Hawaiian monk seals. It is maintained as a field station in the Hawaiian Islands National Wildlife Refuge by the United States Fish and Wildlife Service.