2025 Proclaimed the 'Year of the Octopus' Off Britain's South Coast.

Exceptionally high observations of one of the world's most intelligent invertebrates over the summer months have prompted the naming of 2025 as “the year of the octopus” in a yearly report of UK coastal waters.

A Perfect Storm for a Population Boom

A mild winter and then a very warm springtime triggered unprecedented numbers of common octopuses (*Octopus vulgaris*) to take up residence along the shores from Cornwall to Devon, across the southwestern peninsula.

“The volume of octopuses caught was approximately 13 times what we would usually anticipate in this region,” stated an ocean conservation expert. “Based on the totals, around 233 thousand octopuses were present in British seas this year – representing a massive jump from the norm.”

*Octopus vulgaris* is indigenous to British seas but typically so rare it is rarely seen. A sudden increase is the result of a combination of gentle winter conditions and a warm breeding season. This perfect scenario meant increased juvenile survival, maybe aided by large numbers of a favored prey species noted in recent years.

A Rare Phenomenon

The last time, a population surge of this scale comparable was documented in the mid-20th century, with historical records indicating the one before that was in 1900.

The huge numbers of octopuses meant they could be easily spotted in shallow waters for a rare occurrence. Diver videos show octopuses gathering in groups – unlike their typical solitary behavior – and ambulating along the bottom on the tips of their limbs. One individual was even filmed grabbing a diver's camera.

“On my initial dive there this year I saw five of these creatures,” the officer added. “They are sizeable. We have two species in UK waters. One species is smaller, football-sized, but these newcomers can be reaching impressive sizes.”

Future Prospects and Other Surprises

If conditions remain mild going into 2026 suggests the potential another surge in 2026, because in the past, in similar situations, events have occurred consecutively for two years in a row.

“Still, the chances are low, from previous blooms, that it will persist indefinitely,” they cautioned. “The ocean is full of surprises at the moment so it’s hard to forecast.”

The annual review also highlighted other “surprises, successes and joyful moments” along the coast, including:

• Unprecedented numbers of grey seals recorded in one northern region.
• Record numbers of the iconic seabirds on a Welsh island.
• The first recording of the *Capellinia fustifera* nudibranch in Yorkshire, typically a southwestern species.
• A Mediterranean fish species spotted off the coast of a southern county for the inaugural time.

Environmental Concerns

The year had its low points, however. “The year was bookended by environmental disasters,” noted a conservation leader. “A major tanker collision in March and the release of industrial pellets off the southern coast were serious issues. Dedicated individuals are making huge efforts to defend and heal our coasts.”