Tonga Island Marine Reserve is the third marine reserve to be created alongside a national park. It covers an area of 1835 hectares, extending one nautical mile (1852m) offshore from the mean high water mark of Tonga Island, and the coast between Awaroa Head and the headland separating Bark Bay and Mosquito Bay. The marine reserve protects all marine life within its boundaries, benefiting not just fish and shellfish, but also animals like seals, penguins and other seabirds that live on the land but feed in the sea.