Blue whales are amazing animals. They live in water and they are mammals. blue-grey. They are the biggest They are animals in the world. They are about thirty metres long and weigh about 150,000 kilograms – as much as 2,000 people. The biggest blue whale was 33.6 metres long and weighed 180,000 kilograms. Blue whales live in all oceans of the world. They are the loudest animals on earth. Their noise is louder than a jet plane. They eat krill, plankton and small fish. People killed blue whales for their oil, their meat and their skin. Now there are between 10,000 – 25,000 blue whales in the world.