In the first half of the twentieth century many whales were commercially fished because a wide range of products such as soap and oil could be made from whale body parts. However, whales breed so slowly that it wasn't long before the intensive whaling pushed many species, including the blue whale, to the edge of extinction.
Commercial whaling has now been banned for several decades, and blue whale numbers are slowly increasing. Today there are between 10 000 and 12 000 blue whales living in the oceans around the world