ONCE very rare in British waters, just this winter we have seen a pod of 10 sperm whales and several smaller pods and some individuals washed up dead on our beaches.

The pod of 10 finally beached between Tunstall and Withernsea in East Yorkshire. 

The main reason for so many whale sightings appears to be huge stocks of various species of squid being lured from their normal north Atlantic homes into the North Sea by increasingly warm sea temperatures caused by climate change.

Although squid is the favoured food for sperm and many other whales the shallower and restricted waters of the North Sea off our east coast pose other threats and difficulties to large whales.   

The 10 sperm whale pod that died on the East Yorkshire coast is thought to be the biggest mass stranding of the cetacean in England since scientific records began in 1913.

One of group of ten sperm whales which was beached on a stretch of coastline between the villages of Tunstall and Withernsea in East Yorkshire in December

An unsuccessful rescue operation was launched after the pod of juvenile whales was spotted in shallow water between Tunstall and Withernsea, East Yorkshire at around 8.30am last Christmas Eve.

The British Divers Marine Life Rescue (BDMLR) said it was not able to try to shepherd the 10 sperm whales out to deeper waters due to rough seas.

Because of their size — male sperms reach about 20 metres in length and weigh up to 80 tons — it was not possible to move the whales once they were stranded, and they rarely survive long when beached.

The most recent event of this scale on England’s east coast was back in January of 2016 when a pod of six sperm whales died after becoming stranded.

They were among 30 of the mammals to wash up on coastlines across northern Europe over a period of six weeks in that year.

An investigation into that incident, published in 2018, said the animals had been foraging in Norwegian waters before becoming lost and disoriented in the shallow southern North Sea.

Sperm whales were rarely seen off the British coast as they usually hunted large or medium-sized squid, diving up to 2,000 metres at a time. One came ashore in north Norfolk a month or two ago. 

Scotland is usually home to the largest sightings of whales and dolphins.

Well over 300 sightings in a single year in Scottish waters have included humpback whales feeding in the Inner Hebrides and orcas or killer whales spotted off Shetland and Caithness. 

Groups of Risso’s dolphin are often spotted off the Western Isles, Orkney and north-east Scotland.

A Risso's dolphin pictured in the River Clyde in 2008

England can usually report nearly 300 sightings and Wales approaches 100 sightings in a good year.

The Sea Watch Foundation conducts an annual two-week count of whales, dolphins and porpoises across the country.

The data collected helps to develop a snapshot of the distribution of animals such as orcas, minke whales, humpback whales, bottlenose dolphins, and harbour porpoises.

The foundation welcomes reports of sightings from members of the public. Over 500 sightings of 13 species have been reported in their annual two week survey.

Dr Chiara Giulia Bertulli, organiser of some of the recent surveys including the 2018 event, reported that 527 sightings were submitted after the nine-day count. Species numbers were up 50 per cent on 2017. 

She says: “Cetacean data collection is strongly weather dependent. Factors such as sea state, swell height and visibility to the horizon affect how easily animals can be detected during a watch.

“Heavy rain and wind can even cause watches to be cancelled altogether. For these reasons, every year, we rely heavily on good weather conditions.”

Harbour porpoises can be seen virtually anywhere in Britain, and several dolphin species are regular visitors to our waters.

Occasionally, members of the public can also catch sight of something larger.

During the 2018 summer’s count, the last for which full figures are available, at least 30 minke whale sightings were reported, mostly off the western coasts of Scotland.

Humpback whales were also spotted off the Aberdeenshire and East Yorkshire coasts.

Humpbacks are rarely seen in Britain but their numbers have been rising in recent years, according to Sea Watch. 

In 2013, Norfolk watchers reported their first reliable humpback sighting since records began in the 18th century.

Humpbacks pass each year as part of their migration between feeding grounds in the north Atlantic and breeding grounds in the Caribbean and Azores.

Experts think the rise in British sightings could be linked to a general increase in their population sizes, which have been recovering globally since last century’s commercial whaling bans.

Most stranded whales are claimed and examined by the strandings team at the Natural History Museum based in South Kensington.

It is a dirty and very smelly job where chainsaws often replace scalpels as the tools for post-mortem or autopsy.

The museum often takes casts of large and rare animals and huge animals are rotted in pits until their skeletons can be cleaned and put on show.

A female blue whale skeleton on display at the Natural History Museum in London

Cetacean numbers are also monitored by the museum, and researchers have noted the number of strandings is rising.

Officers at the Cetacean Strandings Programme investigate reports of dead or stranded animals along the coastline — usually hundreds each year. 

Since the programme first began in 1913, there have been more than 12,000 logged reports of whale, dolphin and porpoise strandings, ranging from blue whales to harbour porpoises.

Research assistant Kate Swindells told us: “We continually receive more reports year on year, which is excellent and shows a real increase in public engagement and citizen science, particularly for ocean conservation.

“Whether or not there is an increase in sightings due to more people reporting, or actually an increase in cetaceans in UK waters remains unclear.”

In Scotland, the Scottish Marine Animal Strandings Scheme recently reported a stranded juvenile harp seal, a very rare species usually found only in the Arctic ice fields.

This raised concerns that this ice-dependent species may be changing its behaviour because of climate change and melting sea ice.

There is no doubt that climate change is a major factor in whale and dolphin behaviour.

Higher temperatures and warmer waters have attracted species that normally stay away, like striped dolphins, and created the conditions for plankton fronts to develop. These have encouraged fish, whales and dolphins to gather.

Warmer water species like the short-beaked common dolphin, the Risso’s dolphin and the striped dolphin are extending their range further north.

Since a greater number of species live in warm waters, the effects of climate change can actually be positive at mid-latitudes such as around the British Isles.

It’s not good news for every species, though. If waters warm, there is a risk we could lose other animals, such as the Atlantic white-sided dolphin and white-beaked dolphin.

As well as that, if species that are used to tropical temperatures start making regular visits to Britain, they face a much wider range of human pressures such as pollution along the industrialised coastlines of northern Europe.

Although it is extremely sad to see a dead whale or dolphin, reporting it can help monitor distribution, abundance and threats to their populations.

First do check the animal is dead. It’s important to take care when near a stranded dolphin or whale. A blow from the tail is powerful and can cause serious injury. 

Wear gloves if you have to touch the animal. Don’t try to put it back in the water. Call on expert assistance.

If you do spot a stranded whale or dolphin on the beach phone the Cetacean Strandings Investigation Programme (CSIP) immediately. The number is 0800 652-0333 and calls are free. 

Be ready to give as much information as possible about the animal’s location and condition.