Cetaceans were historically abundant around the island as commercial hunts on the island was operating until 1956. Today, numbers of larger whales have disappeared, but even today many species such humpback whale, minke whale, sei whale, and dolphins can be observed close to shores, and scientific surveys have been conducted regularly. Southern right whales were once regular migrants to the Norfolk hence naming the island as the "Middle ground" by whalers, but had been severely depleted by historical hunts, and further by illegal Soviet and Japan whaling, resulting in none of very few, if remnants still live, right whales in these regions along with Lord Howe Island.