2025 Declared 'The Octopus Year' Off England's Southern Shores.

Unprecedented observations of one of the world's most intelligent invertebrates this past summer have led to the naming of 2025 as the year for octopuses in a yearly report of Britain’s seas.

Ideal Conditions Driving a Surge

A gentle winter followed by a remarkably hot spring triggered a massive influx of *Octopus vulgaris* to settle along England’s south coast, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was roughly 13 times what we would typically see in the waters around Cornwall,” explained an ocean conservation expert. “Based on the totals, nearly a quarter of a million octopuses were present in UK waters this year – that’s a huge increase from historical averages.”

The Mediterranean octopus is indigenous to these waters but typically so rare it is seldom observed. A sudden increase is caused by a combination of gentle winter conditions and favorable spring temperatures. Such favorable circumstances meant more larvae, potentially supported by large numbers of spider crabs noted in recent years.

An Uncommon Occurrence

Previously, an octopus bloom of this size was documented in the 1950s, with past documentation indicating the last bloom prior to that happened in 1900.

The sheer quantity of octopuses meant they could be frequently seen in nearshore environments for a rare occurrence. Underwater recordings show octopuses gathering in groups – unlike their typical solitary behavior – and ambulating along the seabed on their arm ends. One creature was even seen investigating a diver's camera.

“On my initial dive in that area this year I saw multiple octopuses,” they noted. “And these are big. Two kinds exist in the region. The curled octopus is quite small, about the size of a football, but these common octopuses can be reaching impressive sizes.”

Predictions and Marine Joy

Another mild winter heading into next year meant it was possible another surge in 2026, because based on records, in similar situations, populations have surged again for two years in a row.

“Still, the chances are low, from previous blooms, that it will become a permanent fixture,” they stated. “Marine life is unpredictable at the moment so it’s quite an unpredictable situation.”

The assessment also highlighted other “surprises, successes and joyful moments” around the UK coastline, including:

• A record number of grey seals recorded in Cumbria.
• Record numbers of puffins on Skomer.
• The first recording of the *Capellinia fustifera* nudibranch in a northern county, usually found in the south-west.
• A type of blenny discovered off the coast of Sussex for the inaugural time.

Environmental Concerns

Not everything was good news, however. “The calendar year was marked by ecological challenges,” stated an expert. “A major tanker collision in March and the release of tonnes of plastic biobeads off the Sussex coast served as stark reminders. Dedicated individuals are working tirelessly to defend and heal our marine habitats.”