2025 Hailed as 'The Octopus Year' Off Britain's South Coast.

Exceptionally high sightings of a supremely intelligent sea creature over the summer months have led to the designation of 2025 as the year for octopuses in a yearly report of the nation's marine environment.

Ideal Conditions Leading to an Explosion

A gentle winter followed by a remarkably hot spring triggered a huge population of *Octopus vulgaris* to take up residence along the shores from Cornwall to Devon, from Penzance in Cornwall to south Devon.

“The volume of octopuses caught was approximately over a dozen times what we would typically see in Cornish waters,” commented a marine conservation officer. “Based on the totals, nearly a quarter of a million octopuses were caught in UK waters this year – representing a massive jump from what is typical.”

*Octopus vulgaris* is found in British seas but usually so scarce it is infrequently encountered. A sudden increase is the result of a combination of a mild winter and a warm breeding season. This perfect scenario meant increased juvenile survival, possibly in part fuelled by large numbers of spider crabs also recorded.

A Rare Phenomenon

The most recent occasion, an octopus bloom comparable was recorded in the 1950s, with archival data indicating the one before that happened in the turn of the 20th century.

The sheer quantity of octopuses meant they could be easily spotted in coastal areas for the first time in recent history. Underwater recordings show octopuses congregating together – they are usually solitary – and moving along the seabed on the tips of their limbs. A curious octopus was even filmed grabbing a diver's camera.

“The first time I dived off the Lizard peninsula this year I saw multiple octopuses,” the specialist continued. “They are large specimens. There are two types in these waters. One species is rather small, the size of a ball, but these common octopuses can be reaching impressive sizes.”

Looking Ahead & Coastal Highlights

Another mild winter going into 2026 meant it was possible a repeat event next year, because based on records, with such patterns, the blooms have repeated for two consecutive years.

“But, it's improbable, from previous blooms, that it will go on for a long time,” they cautioned. “The ocean is full of surprises these days so it’s hard to forecast.”

The annual review also noted additional positive marine news around the UK coastline, including:

• A record number of grey seals recorded in one northern region.
• Peak numbers of the iconic seabirds on an island off Wales.
• A first-ever sighting of an unusual mollusc in a northern county, usually found in the south-west.
• A type of blenny discovered off the coast of a southern county for the first time.

A Note of Caution

Challenges were also present, however. “The period was framed by environmental disasters,” said a head of marine conservation. “A major tanker collision in March and the release of tonnes of plastic biobeads off the southern coast highlighted ongoing threats. Dedicated individuals are making huge efforts to protect and restore our marine habitats.”