The blue whale is the largest creature to have lived on Earth – ever! It’s even bigger than any of the dinosaurs were. This massive marine mammal quietly cruises across the world’s oceans in search of food and to raise a family. It’s hard to believe that we very nearly lost this awesome animal altogether.
Everything about the blue whale is BIG!
• It measures up to 30 metres in length – longer than three buses!
• It can weigh over 150 tons – that’s as heavy as 30 elephants!
• A blue whale’s heart is the size of a small car!
• Its tongue is so big a whole football team could stand on it!
• Its calls are louder than a jet plane. They can be heard by other blue whales over 1,000km away!
• A blue whale lives for 80 to 90 years!
The blue whale is the biggest animal in the ocean, but it eats one of the smallest. It feeds on krill – tiny, shrimp-like crustaceans that swim about in the water. A blue whale needs to gulp down about 40 million krill every day!
Blue whales migrate as the seasons' change. Many spend the summer at their favourite feeding grounds, near the Arctic and Antarctic, filling up on krill. Then they move to warmer, tropical waters for the winter, to breed and give birth. Travelling between the two areas takes a blue whale up to four months, and it can cover thousands of kilometres on the way. That’s one amazing migration!
The blue whale isn’t hunted any more, but it is still threatened by several things:
1. Climate change could mean that our oceans get warmer. This might affect the availability of krill.
2. Noise from ships and drilling for oil and gas can confuse blue whales and make it harder for them to communicate with one another.
3. Ships can kill or injure whales if they hit them. Whale-watching boats can disturb their normal behaviour.
4. Fishing nets can trap and drown whales.
5. Ocean pollution can poison whales.
6. Whaling is banned at the moment, but if the number of blue whales keeps increasing, people might want to start hunting them again.
What would the world be like without the blue whale? If we want it to carry on cruising our seas for centuries to come, we need to learn from the past and look after this gentle giant of the ocean.