Warmer seas bring record number of octopuses to UK waters

A wildlife charity has declared 2025 the “Year of the Blooming Octopus” after record numbers were spotted on the south-west coast of England.

The Wildlife Trusts say in its annual marine survey that octopus numbers this summer are at their highest since 1950.

Warmer winters associated with climate change are thought to be responsible for population growth, known as “blooming”.

The charity’s findings are supported by official figures showing more than 1,200 tonnes of octopus were caught by fishermen in UK waters in the summer of 2025.

There is a dramatic increase compared to previous years. Only once since 2021 have more than 200 tonnes of octopus been landed.

Experts say most of those detected were Octopus vulgaris, a species common in the warm Mediterranean. Wildlife Trust volunteers in Cornwall and Devon reported a more than 1,500 per cent increase in cases on part of the south coast compared to 2023 figures.

“It’s truly remarkable,” says Matt Slater of Cornwall Wildlife Trust. “We’ve seen octopuses that propel themselves by jet thrust. We’ve seen octopuses that camouflage themselves, they look just like seaweed.

“We’ve seen them groom themselves. We’ve even seen them walk underwater, using their two legs to nonchalantly move away from the diver.”

It is unclear at this stage whether the increase in numbers is permanent or cyclical; This means octopus numbers will return to more typical levels after this year’s bloom.

The eight-armed cephalopods eat shellfish such as lobsters, crabs and scallops, so the Wildlife Trust warns that both fishing and eating habits may need to change if population numbers remain high.

Ruth Williams, head of marine at The Wildlife Trusts, told the BBC’s Today programme: “It has impacts on the shellfish species around our coasts. And as a result, it will also have impacts on our fishing industry, which targets those species.”

“But there are opportunities and our fishing industry is currently doing some research to try to evolve with the changing fisheries we see as a result of climate change.”

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

As well as good news for octopus lovers, the Wildlife Trusts’ marine review contains even more sobering news.

Foundations say this year has been full of environmental disasters, with a collision between an oil tanker and a container ship in the North Sea in March. large quantities of plastic resin pelletsand almost 4.5 tonnes of biobeads released from a water treatment plant in Sussex In November.

A record number of 46,000 gulls were recorded in Skomer, Pembrokeshire, and the charismatic black and white bird has made a comeback on the Isle of Muck following conservation efforts by the Ulster Wildlife Trust to eradicate invasive brown mice.