2025 Declared 'The Octopus Year' Off England's Southern Shores.

Unprecedented encounters of one of the world's most intelligent invertebrates over the summer months have prompted the declaration of 2025 as “the year of the octopus” in an annual review of Britain’s seas.

A Perfect Storm Driving a Surge

A gentle winter and then a very warm springtime prompted a huge population of *Octopus vulgaris* to settle along the shores from Cornwall to Devon, across the southwestern peninsula.

“The scale of the catch was approximately thirteen times what we would normally expect in Cornish waters,” commented a marine conservation officer. “When we added up the numbers, nearly a quarter of a million octopuses were present in these waters this year – that’s a huge increase from the norm.”

*Octopus vulgaris* is found in UK waters but usually so scarce it is seldom observed. An explosive growth is the result of a combination of gentle winter conditions and a warm breeding season. Such favorable circumstances meant a higher survival rate for young, potentially supported by significant populations of spider crabs also recorded.

A Rare Phenomenon

The last time, a population surge of this scale comparable was observed in the 1950s, with archival data indicating the one before that occurred in 1900.

The huge numbers of octopuses meant they could be readily observed in coastal areas for the first time in living memory. Video footage show octopuses congregating together – contrary to their normally lone nature – and ambulating along the ocean floor on the tips of their limbs. A curious octopus was even filmed grabbing a diver's camera.

“On my initial dive in that area this year I saw five of these creatures,” the specialist continued. “They are large specimens. Two kinds exist in these waters. One species is rather small, football-sized, but these common octopuses can be reaching impressive sizes.”

Looking Ahead & Coastal Highlights

A second gentle winter going into 2026 suggests the potential another surge in 2026, because based on records, with such patterns, the blooms have repeated for two years in a row.

“However, it is unlikely, based on past events, that it will persist indefinitely,” they cautioned. “The ocean is full of surprises currently so it’s quite an unpredictable situation.”

The annual review also celebrated further encouraging coastal sightings around the UK coastline, including:

• A record number of grey seals seen in one northern region.
• Record numbers of puffins on an island off Wales.
• The initial discovery of a rare sea slug in a northern county, usually found in the south-west.
• A type of blenny discovered off the coast of Sussex for the inaugural time.

Environmental Concerns

Challenges were also present, however. “The calendar year was marked by marine incidents,” said a head of marine conservation. “A significant shipping incident in March and a spill of industrial pellets off the Sussex coast highlighted ongoing threats. Conservation teams are working tirelessly to defend and heal our coasts.”