Whales UK

Is it possible that more than five whales from this pod have died?

Five young male whales have now been found dead – in Hunstanton, Skegness and Wainfleet, all around the shallow waters of the Wash.

But 12 other whales were washed up on the Wadden Islands archipelago off the coast of Germany and the Netherlands earlier this month. And more deaths may come: at least one further sperm whale was sighted off the Norfolk coast last week.

Are the numbers of whale strandings increasing?

Sperm whale strandings in UK waters remained steady at one a year during the 20th century but suddenly leapt to about seven a year in the 1980s, according to Peter Evans, director of the Sea Watch Foundation charity. Since then, they have stabilised at about six a year.

Sightings have also increased – even allowing for more people looking – which may be good news. Since whaling was banned, the number of large males in their southern Atlantic strongholds may have increased, pushing out juvenile males.

Related: Three dead sperm whales wash up on Skegness beach

These young males head north, enter the North Sea between Scotland and Norway, and unfortunately find this shallow sea a natural trap – difficult to navigate and short of food. More humpback whales have been found stranded in Britain since 1986, when hunting them was banned.

What has caused these sperm whale strandings?

In their 170-metre-long intestine (one of the longest of any creature), he found some squid beaks and monkfish bones, showing that the whales had eaten and were not completely starving. Two whales also contained fishing line and hooks, suggesting they had nabbed fish from a fishing boat’s “long line” (a more environmentally friendly form of fishing).

This would not be fatal but if the British whales also have fishing lines, it’s strong evidence that they all belong to the same “bachelor pod”.

If they were not starving, did we inadvertently kill them?

The Dutch whales examined by Brownlow were not victims of a ship strike or entanglement in fishing nets. “But some things would never leave a pathological legacy, such as if they were startled and disorientated by noise, ” said Brownlow.

What about noise from naval exercises or sonar?

“If there was a massive naval exercise off the coast of Norfolk at the weekend I would be hugely suspicious but as far as I can tell, that’s not the case, ” says Brownlow. Four large bombs exploded underwater by the Royal Navy killed 19 pilot whales off Scotland in 2011 but scientists point out that the navy is less likely to undertake significant exercises in midwinter.

Rob Deaville, project manager of the UK Cetacean Strandings Investigation Programme, the environment department-funded organisation, which investigates whale deaths, said they would be seeking more information from the Ministry of Defence about possible military exercises.

The North Sea is full of windfarms and oil rigs. Could these have disoriented them?

No, says Peter Evans. The noise from pile-driving during windfarm construction can affect marine mammals such as porpoises but once they are established they probably help cetaceans by creating fish-rich artificial reefs.