Record number of seabirds and dolphins migrate from coast due to global warming

By Jake Meeus-Jones

Experts say warming sea temperatures have caused unprecedented changes to the wildlife on the Devon coastline - with record numbers of birds which would usually be found in Spain and France.

MARINElife conducted surveys off Lyme Bay, Devon, earlier this month - looking at the numbers of wildlife off the coast.

And scientists were astonished to see huge numbers of animals usually seen in traditionally-warmer water, off continental Europe.

Tom Brereton of the marine charity said his team counted 1,920 Balearic shearwater birds on one day - surpassing the previous UK record site day count of 1,145 made in 2023, up by a startling 68%.

The Balearic shearwater is critically endangered and typically found in the Balearic Islands, east of Spain before migrating north to the Bay of Biscay - between western France and northern Spain - for moulting.

But in recent years increasing numbers of post-breeding Balearic shearwaters birds have shifted north to the English Channel, coinciding with warming sea temperatures and northward shifts in anchovies.

Other rare sea creatures were also seen on the trip - including tuna fish usually seen in the Canary Islands, driven north from sea temperatures and an eco-system shift.

This shift also brought unusually large numbers of previously rare crystal jellyfish - usually seen in Mediterranean waters - to the UK and an ocean sunfish.

The survey also recorded three pods of Rissos’ dolphin and large numbers of common dolphin.

Risso's dolphin have shown up in unprecedented numbers this summer, following a large influx of Mediterranean octopus, which they eat, because of warmer waters.

According to Tom, if Risso's dolphins are seen more than once a year, it's rare.

A rare Wilson's storm petrel, a seabird more frequently seen in the Bay of Biscay and eastern North America, was also seen and photographed for the first time in Devon waters - after breeding season.

While common in waters around the Isles of Scilly, Wilson's storm petrels are rarely seen further along the southern coast.

Tom, research director of the MARINElife charity, said: "The southwest marine environment is changing rapidly from plankton communities at the base of the chain, through to top predators such as Balearic Shearwaters.

"The weather is related to the food sources - that causes the food sources to shift north.

"East of Portland Bill in Portsmouth is more influenced by the North Sea so the water is colder and generally colder and mixed, whereas in the west of the English Channel it's warmer and the surface temperature is warmer than below.

"We've got tuna, sharks, octopus and Balearic shearwaters all that 15 years ago were off the west coast of central France.

"There's a pod of killer whales that normally go to Gibraltar in July and August but that pod is off Cornwall at the moment.

"I remember giving a talk 20 years ago or so wondering if it's going to happen - it's happening now."

Tom believes that the increase in numbers of these birds and sea creatures could provide UK tourism with a boost, but that the priority should be about protecting them.

He said: "It could lead to some good opportunities.

"From being an incredible rarity there are now massive numbers in the channel.

"There's obviously a lot of food as well - normally you get some hotspots, but this time it was absolutely everywhere.

"It's not always what's happening where we are as well - the driver for all those Mediterranean octopus arriving is a result of previous years or warmer periods in the Winter.

"But the southwest has been above average for three or four degrees for this year.

"We must act quickly to ensure that species such Balearic shearwater, bluefin tuna and other new arrivals are adequately protected whilst in our waters."

The survey took place on July 24 and was done in collaboration with Naturetrek, who run ecotourism trips.

Andy Tucker, managing director of Naturetrek, said: "We were delighted to give our wildlife watching clients a trip of lifetime and at the same time contribute to vital research on the endangered Balearic shearwater species, one that is even rarer and more threatened with extinction than the polar bear."