Warmer seas bring record number of octopuses to UK waters

A wildlife charity has declared 2025 the “Year of the Blooming Octopus” after a record number of them were discovered off the south-west coast of England.

In its annual marine environment review, the Wildlife Trust says octopus numbers this summer reached their highest level since 1950.

Warmer winters associated with climate change are thought to be responsible for the population surge known as the “bloom.”

The charity's findings are supported by official data, which shows that fishermen in UK waters caught more than 1,200 tonnes of octopus in the summer of 2025.

This is a significant increase compared to previous years. More than 200 tons of octopus have been caught just once since 2021.

Experts say most of those spotted are Octopus vulgaris, a species typically found in the warmer Mediterranean Sea. Wildlife Trust volunteers in Cornwall and Devon have reported an increase in sightings of more than 1,500 per cent compared to 2023 figures at one site on the south coast.

“It really was exceptional,” says Matt Slater from the Cornwall Wildlife Trust. “We've seen octopuses fly on jet planes. We have seen how octopuses camouflage themselves, they look like seaweed.

“We saw them cleaning themselves. And we've even seen them walk using two legs just to casually get away from a diver underwater.”

It's unclear at this point whether the population increase is constant or cyclical, which would mean octopus numbers will return to more typical levels after this year's bloom.

The eight-armed cephalopods feed on shellfish such as lobsters, crabs and scallops, so Wildlife Trusts warn that if population numbers remain high, both fishing and feeding habits may have to change.

“They are having an impact on those (shellfish) species off our shores. And as a consequence they will have an impact on our fishing industry, which also targets these species,” Ruth Williams, head of marine at The Wildlife Trusts, told the BBC Today programme.

“But the opportunity is there and our fishing industry is currently doing some research in this direction to try to evolve with the changes in fisheries that we are seeing as a result of climate change.”

Government data shows Crab catches were down from previous years, but lobster, crayfish and scallop catches remained stable.

As well as the good news for octopus lovers, the Wildlife Trust's marine review contains some more sobering news.

The funds say the year has been marked by environmental disasters, with an oil tanker colliding with a container ship in the North Sea in March causing an oil spill. huge amount of plastic resin granulesand almost 4.5 tonnes of biobeads released at Sussex water treatment plant in November.

There was good news for wildlife elsewhere, with a record 46,000 puffins recorded in Skomer, Pembrokeshire, while the charismatic black and white bird returned to the Isle of Mack following Ulster Wildlife Trust's conservation efforts to remove invasive brown rats.