Heron Island is also a major nesting site for green ("Chelonia mydas") and Indopacific loggerhead sea turtles ("Caretta caretta gigas"). Around 98% of all turtles that nest on the island are green turtles, and only 2% of them will be loggerheads. The Indopacific hawksbill sea turtle ("Eretmochelys imbricata bissa") has been seen on the reef but does not breed on the island. Other marine life includes the inhabitants of the coral reef, and around early October, cetaceans (e.g. humpback whales, "Megaptera novaeangliae") pass Heron Island on their migration to their summer quarters in subantarctic waters.