2025 Declared 'The Octopus Year' Off England's South Coast.

Unprecedented encounters of a remarkably clever cephalopod during the summer season have prompted the naming of 2025 as the octopus's year in an annual review of Britain’s seas.

A Confluence of Factors Driving a Surge

A gentle winter coupled with a very warm springtime prompted unprecedented numbers of common octopuses (*Octopus vulgaris*) to settle along the southern coastline of England, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was approximately thirteen times what we would typically see in Cornish waters,” commented a marine conservation officer. “Based on the totals, approximately 233,000 octopuses were found in British seas this year – representing a massive jump from what is typical.”

The common octopus is native to UK waters but ordinarily in such small numbers it is infrequently encountered. An explosive growth is the result of the dual effect of gentle winter conditions and favorable spring temperatures. Such favorable circumstances meant increased juvenile survival, potentially supported by abundant stocks of spider crabs seen in the area.

An Uncommon Occurrence

The most recent occasion, a population surge of this scale this significant was documented in the 1950s, with historical records indicating the one before that occurred in 1900.

The huge numbers of octopuses meant they could be readily observed in coastal areas for a rare occurrence. Diver videos show octopuses gathering in groups – unlike their typical solitary behavior – and “walking” along the seabed on their tentacle tips. A curious octopus was even filmed grabbing a diver's camera.

“During a first dive off the Lizard peninsula this year I saw five of these creatures,” the officer added. “They are large specimens. Two kinds exist in UK waters. One species is rather small, the size of a ball, but these common octopuses can be reaching impressive sizes.”

Predictions and Marine Joy

A second gentle winter this coming winter could lead to a repeat event next year, because in the past, in similar situations, the blooms have repeated for two years running.

“However, it is unlikely, from previous blooms, that it will become a permanent fixture,” they cautioned. “The ocean is full of surprises these days so it’s hard to forecast.”

The assessment also highlighted further encouraging coastal sightings around the UK coastline, including:

• Highest-ever counts of grey seals recorded in one northern region.
• Peak numbers of puffins on Skomer.
• The initial discovery of an unusual mollusc in Yorkshire, usually found in the south-west.
• A type of blenny spotted off the coast of a southern county for the first time.

Environmental Concerns

Challenges were also present, however. “The period was framed by marine incidents,” said a head of marine conservation. “A major tanker collision in March and a spill of tonnes of plastic biobeads off the southern coast highlighted ongoing threats. Staff and volunteers are making huge efforts to safeguard and rehabilitate our marine habitats.”