Mirounga leonina, southern elephant seal. Although seals spend a lot of time in the water, they evolved from a land-dwelling ancestor over 25 million years ago and still have to come back on land to breed.

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Whale fin

Whale stranding

Why do these amazing animals land on our shores?

Did you know every year in the UK between 350 and 800 whales, dolphins and porpoises (cetaceans) wash up on British shores? Most are already dead, but some are still alive.

Sperm whale stranded on a beach

Sperm whale stranded on a beach

Dead on arrival

The majority of whales that come to our shores are washed up, already dead. There are a number of reasons why they may have died.

  • Disease – caused by parasites, viruses or a suppressed immune system (pollution, stress and starvation can make an animal’s immune system weaker and more vulnerable to diseases).
  • Natural mortality – death from old age, death of mother or calf during birth (calves still dependent on their mother's milk can become separated and starve).
  • Pollution – the deadly effects caused by chemicals from industrial, agricultural or domestic sources (factories, farming and home waste).
Alive but not well

You may have seen news stories of live whales stranded on a beach, when efforts have been made to get the animal back into the water, occasionally with some success.

What makes a live whale beach itself? Most cetaceans use their own form of sonar and are sensitive to the Earth’s magnetic field – they use both of these to navigate and find their food. Several things can affect these otherwise amazing skills.

  • Navigation error – whales and dolphins sometimes get lost as they use the Earth’s magnetic fields to navigate the seas. There are a number of things (that we don’t yet fully understand) that may cause the animals to become confused, causing them to mis-read these magnetic lines and become lost.
  • Noise pollution – anthropogenic (human-made) noise from drilling, dredging, shipping, offshore developments and seismic surveys can cause disorientation and distress.
  • Naval sonar – the effects of sound waves from submarines used by the military (for detecting other submarines, ships etc) can disorientate whales and dolphins.

Some species of cetaceans are very social animals and travel in family groups following a dominant leader. Tragically, if the group leader is sick and swims into shallow water, all the others may follow and become stranded together.

Fishes Royal

A law was enacted in 1324 that all whales, dolphins and porpoises found in English waters belonged to the King (or Queen as we have now) and were to be known as ‘Fishes Royal’. The Natural History Museum was given the responsibility for investigating all the strandings since 1913 and runs the UK Whale and Dolphin Stranding Scheme. There have been more than 11,000 strandings so far.

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