Humpback whales in the English Channel: What’s behind the sightings?

Cetaceans in UK waters are nothing new. Minke whales, dolphins and porpoises are often seen off the British coast. But recent sightings of a much bigger visitor have caused both excitement and concern among locals and scientists.

Over the last few weeks, multiple sightings of the magnificent humpback whale have been reported by people living along the coast. These 15-metre long animals have been spotted in growing numbers at various locations along the southern coast, from Kent in the southeast to the Isles of Scilly. 

In just 11 days between 29 December and 8 January, there were 17 reported sightings of humpback whales around the Scilly Isles, including one that locals have named ‘Pi’. Identified by an unusual marking on her fluke, Pi has been visiting the archipelago every year since 2019.

But seeing humpback whales in the English Channel is far more rare. Thea Taylor, Managing Director at the Sussex Dolphin Project, told the BBC that, since 2020, there are usually one or two sightings around the southeast coasts, but this year has been exceptional.

At least 30 sightings have been recorded this winter, from Deal and Dungeness in Kent to Eastbourne and Hastings in Sussex. It’s not clear whether these are multiple sightings of the same group or of different animals.

Once hunted to the brink of extinction, the humpback whale population has recovered extensively over the past half a century. In 1960, numbers were estimated at around 5,000 animals. Today, the population is estimated to be around 84,000 individuals.

Of those, 13,000 live in the North Atlantic in two populations. From spring to autumn, they feed in cold, productive waters off the Gulf of Maine, Greenland, Iceland and Norway, while in the winter they migrate to the West Indies and Cape Verde to mate and calve.

Why are humpback whales swimming in the English Channel?

The jury is still out on the precise reason for these increased sightings, but one theory is that there are simply many more of the creatures for us to spot. 

The incredible recovery of the species since the ban on commercial whaling brings with it some challenges for our giant friends. Younger males may be forced to explore new breeding grounds and feeding areas to avoid competition with larger and more established males.

Taylor posits that these whales are coming from feeding grounds in the Arctic Circle, and are using the English Channel to travel back to warmer waters. Still, she doesn’t understand why this new route is being exploited rather than the regular track around the west coast of the UK.

Another theory is that climate change is impacting where humpback whales spend their time. Warmer waters affect much of a humpback whale’s environment, from where its prey live to the availability of habitat.

Cornwall Wildlife Trust notes that, in 2023, water temperatures were warmer, which saw some range extension of southern species that are not native to the region. Conversely, cold-water species such as the plumose anemone have dramatically reduced in abundance.

“Since 2015 there have been marked increases in many cetacean species in inshore waters,” says the Wildlife Trust. “There is limited ongoing research investigating this shift and cetacean research in the UK continues to be poorly funded.”

The National Oceanic and Atmospheric Administration (NOAA) states that, “The impacts of climate change on whales are unknown, but it is considered one of the largest threats facing high latitude regions where many humpback whales forage.”

It further states that changing water temperatures and sea ice melt will impact everything from prey distribution to breeding ground locations, adding, “changing water temperature and currents could impact the timing of environmental cues important for navigation and migration.”

The risks to the whales of their new route

The English Channel is considered the busiest shipping lane in the world. More than 500 vessels navigate through and across the channel every day.

These range from small leisure craft and passenger ferries to giant container ships. Some of the largest ships are more than 300 metres long, with drafts (the portion of the ship below water) extending to 12 metres.

It is estimated that thousands of humpback whales are struck by vessels every year, although the exact number is hard to define. It is estimated only 10 per cent of whale strikes are reported, and some ships may not even know they’ve hit an animal.

The World Sustainability Organization estimates as many as 20,000 whales are killed every year by boats, from fishing vessels to cruise ships. It says shipping companies can protect the species by reducing speeds to below 13 knots in high-risk areas.

The English Channel does not have a universal speed limit for ships, but instead relies on ‘safe navigation speed’ dependent on factors like weather, traffic and location.

While British spectators will enjoy seeing the animals pass by, each sighting is another whale risking its life in the busiest shipping lane in the world.

Where else in Europe can you spot humpback whales?

Europe is a great place for whale watching. Some 36 species of cetaceans can be seen in the waters, from Greenland east to the Russian Arctic and south to the Canary Islands and the Mediterranean Sea.

For humpback whales specifically, northern Norway, Greenland and Iceland are hotspots.

In the winter in Norway, humpback whales gather in the fjords near Tromso in search of the huge schools of herring found there. Groups of whales will corral the fish into a tight ball, blowing bubbles to trap them in a shrinking circle. Some even slap their tails to scare the fish, before the group launches a coordinated attack, swimming upward and scooping the ball into their mouths.

Iceland and Greenland see more humpback whale activity in the summer months. Husavik, in the north of Iceland, is known as the ‘whale watching capital,’ where visitors can take a trip on a traditional wooden fishing boat to view humpback and blue whales as well as dolphins and porpoises.

But there’s a chance of seeing a humpback whale pretty much anywhere in Europe as their numbers rise. Spotting them in the Mediterranean or along the coasts of France and Spain is rare, but not unheard of, so keep your eyes peeled next time you’re at the beach.

As always, be responsible when looking for wild animals. Always go spotting with a certified guide and keep your distance so as not to disturb the animals.