How can the blue whale survive?

Like all animals, whales need oxygen, which they get by coming to the surface to get a breath of air. They need water, which they drink from the ocean, and then they filter out the excess salt through their kidneys. They also need food, which, for most whales, means krill or small fish. Most species of whale can only get food from the polar regions, and therefor their habitats their need to be protected. During the winter, most whales move south to tropical or subtropical waters to breed. These areas must also be protected. The primary threat to whales is human whalers, which, thanks to an international treaty, has almost ceased. However, Japanese whalers are still taking their toll on the whale population. For people to protect whales, the Japanese must stop whaling soon.