2025 Declared the 'Year of the Octopus' Off England's Southern Shores.

Exceptionally high encounters of a supremely intelligent sea creature this past summer have resulted in the naming of 2025 as “the year of the octopus” in an annual review of UK coastal waters.

A Perfect Storm Driving a Surge

An unusually warm winter coupled with a remarkably hot spring triggered a huge population of Mediterranean octopuses to establish themselves along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was approximately thirteen times what we would typically see in the waters around Cornwall,” stated a marine life specialist. “Calculating the figures, around 233 thousand octopuses were found in these waters this year – representing a massive jump from the norm.”

The Mediterranean octopus is native to British seas but typically so rare it is infrequently encountered. A sudden increase is caused by the dual effect of a mild winter and favorable spring temperatures. Such favorable circumstances meant more larvae, potentially supported by large numbers of spider crabs seen in the area.

A Rare Phenomenon

The last time, a population surge of this scale this significant was documented in 1950, with archival data indicating the previous major event occurred in the turn of the 20th century.

The sheer quantity of octopuses meant they could be frequently seen in nearshore environments for the first time in recent history. Diver videos show octopuses congregating together – contrary to their normally lone nature – and moving along the ocean floor on the tips of their limbs. One individual was even seen investigating a diver's camera.

“During a first dive there this year I saw five octopuses,” the officer added. “And these are big. We have two species in the region. The curled octopus is quite small, about the size of a football, but these common octopuses can be up to a metre and a half wide.”

Looking Ahead & Coastal Highlights

Another mild winter heading into next year meant it was possible a repeat event next year, because historically, in similar situations, events have occurred consecutively for two years in a row.

“Still, the chances are low, looking at history, that it will persist indefinitely,” they said. “Marine life is unpredictable currently so it’s a very uncertain scenario.”

The assessment also celebrated other “surprises, successes and joyful moments” along the coast, including:

• Highest-ever counts of gray seals recorded in one northern region.
• Peak numbers of puffins on a Welsh island.
• The initial discovery of an unusual mollusc in Yorkshire, typically a southwestern species.
• A Mediterranean fish species found off the coast of Sussex for the inaugural time.

Environmental Concerns

Challenges were also present, however. “The year was bookended by ecological challenges,” noted a conservation leader. “A significant shipping incident in March and an accidental discharge of industrial pellets off the southern coast served as stark reminders. Dedicated individuals are putting in immense work to protect and restore our coasts.”