Blue whales are thought to be the largest animal ever to live on the Earth. They reach lengths up to about 100 feet and weights of an amazing 100-150 tons.
Blue whales are found in all the world's oceans. After the invention of the grenade-tipped harpoon in the late 1800's, blue whales were subjected to relentless hunting. The blue whale was given protection from hunting in 1966 by the International Whaling Commission and today there are an estimated 10,000-15,000 blue whales in the world.