2025 Proclaimed the 'Year of the Octopus' Along Britain's Southern Shores.

Exceptionally high encounters of a remarkably clever cephalopod this past summer have led to the designation of 2025 as “the year of the octopus” in an annual review of UK coastal waters.

Ideal Conditions Leading to an Explosion

An unusually warm winter followed by a remarkably hot spring prompted a huge population of *Octopus vulgaris* to settle along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was approximately 13 times what we would usually anticipate in the waters around Cornwall,” explained a marine conservation officer. “Calculating the figures, around 233 thousand octopuses were caught in these waters this year – that’s a huge increase from historical averages.”

*Octopus vulgaris* is found in UK waters but ordinarily in such small numbers it is rarely seen. A sudden increase is caused by the dual effect of a mild winter and a warm breeding season. Such favorable circumstances meant a higher survival rate for young, potentially supported by abundant stocks of other marine life noted in recent years.

A Historic Event

The last time, such an octopus proliferation this significant was recorded in 1950, with archival data indicating the last bloom prior to that happened in 1900.

The huge numbers of octopuses meant they could be frequently seen in nearshore environments for the first time in recent history. Video footage show octopuses congregating together – unlike their typical solitary behavior – and ambulating along the ocean floor on their tentacle tips. A curious octopus was even filmed grabbing a diver's camera.

“The first time I dived off the Lizard peninsula this year I saw five of these creatures,” the officer added. “They are sizeable. There are two types in the region. The curled octopus is quite small, the size of a ball, but these common octopuses can be with a span of 1.5 meters.”

Looking Ahead & Coastal Highlights

A second gentle winter this coming winter could lead to another surge in 2026, because based on records, under these conditions, populations have surged again for two years running.

“Still, the chances are low, looking at history, that it will become a permanent fixture,” they said. “The ocean is full of surprises these days so it’s a very uncertain scenario.”

The report also celebrated additional positive marine news around the UK coastline, including:

• A record number of grey seals observed in Cumbria.
• Exceptional populations of the iconic seabirds on a Welsh island.
• The first recording of a rare sea slug in a northern county, usually found in the south-west.
• A variable blenny discovered off the coast of Sussex for the first time.

Not All Positive News

Challenges were also present, however. “The calendar year was marked by ecological challenges,” said a head of marine conservation. “A significant shipping incident in March and the release of tonnes of plastic biobeads off the southern coast served as stark reminders. Staff and volunteers are putting in immense work to defend and heal our marine habitats.”