 Southern right whales have become rare today, though whales were historically abundant before they were wiped out by commercial and illegal hunts including mass illegal hunts by the Soviet Union and Japan in the 1960s and 1970s.Resident populations of the Indo-Pacific humpbacked dolphin and the Indian Ocean bottlenose dolphin occur in the waters around the island.The bottlenose dolphin's abundance fluctuates seasonally, increasing during the austral winter.