Photo credit: Getty Images
By BBC News Magazine
Five sperm whales have washed up in England. They are thought to belong to the same all-male pod as 12 others that were found dead around the Netherlands and Germany last week. But what caused this mass death, asks Claire Bates.
Sperm whales are deep-sea mammals that tend to live and hunt at a depth of around 3,000m. While females and their young stick to the tropics, males range further afield and are regularly spotted around Iceland, Norway and Shetland.
However, they quickly run into trouble if they enter the North Sea. This is because it lies on the European continental shelf, where the seafloor is only 200m down at its deepest point.
Sperm whales rely on sonar to navigate. They send out sound pulses, which bounce back off distant surfaces, helping them to form a clear picture of their underwater world. This doesn’t work on a shallow sandy seabed, like Britain’s, and whales quickly become disorientated.
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