Humans have hunted whales for their meat, oil and baleen, or whalebone, since at least 6,000 BC. Early whalers hunted these large marine mammals from canoes and skin boats and, if lucky, killed one whale or two. All that changed in the 17th century. Whaling, as whale hunting is called, became an organized chase. The English, Dutch, Spanish and others organized fleets of ships to harvest whales and set up whaling stations to boil blubber into oil. Whalers whaled the world's oceans for the next 300 years. Whales were hunted and harvested until some whale species such as the gray whale, blue whale, northern right whale and sei whale were nearly extinct. And while whaling is banned today some countries - Japan, Norway and Iceland - still hunt whales.