2025 Proclaimed The Year for Octopuses Off Britain's South Coast.

Record-breaking observations of a remarkably clever cephalopod during the summer season have led to the declaration of 2025 as “the year of the octopus” in an annual review of UK coastal waters.

Ideal Conditions for a Population Boom

A gentle winter followed by a very warm springtime prompted a huge population of *Octopus vulgaris* to establish themselves along England’s south coast, spanning the Cornish and Devonian coasts.

“The reported landings was approximately over a dozen times what we would normally expect in the waters around Cornwall,” explained a marine conservation officer. “When we added up the numbers, around 233 thousand octopuses were present in these waters this year – representing a massive jump from what is typical.”

The Mediterranean octopus is indigenous to UK waters but typically so rare it is rarely seen. A population bloom is attributed to a combination of a mild winter and favorable spring temperatures. This perfect scenario meant increased juvenile survival, possibly in part fuelled by abundant stocks of spider crabs also recorded.

A Rare Phenomenon

The most recent occasion, a population surge of this scale comparable was recorded in the 1950s, with historical records indicating the last bloom prior to that happened in the turn of the 20th century.

The remarkable abundance of octopuses meant they could be readily observed in coastal areas for a rare occurrence. Video footage show octopuses being sociable – contrary to their normally lone nature – and “walking” along the bottom on their arm ends. One individual was even seen investigating submarine recording equipment.

“During a first dive there this year I saw multiple octopuses,” the officer added. “And these are big. Two kinds exist in UK waters. One species is smaller, about the size of a football, but these common octopuses can be with a span of 1.5 meters.”

Predictions and Marine Joy

If conditions remain mild going into 2026 could lead to a second bloom the following year, because historically, in similar situations, populations have surged again for two years running.

“But, it's improbable, looking at history, that it will become a permanent fixture,” they said. “Marine life is unpredictable currently so it’s hard to forecast.”

The assessment also celebrated other “surprises, successes and joyful moments” across British shores, including:

• Unprecedented numbers of grey seals observed in one northern region.
• Exceptional populations of the iconic seabirds on an island off Wales.
• A first-ever sighting of the *Capellinia fustifera* nudibranch in a northern county, normally residing farther south.
• A Mediterranean fish species found off the coast of a southern county for the first time.

A Note of Caution

Not everything was good news, however. “The calendar year was marked by marine incidents,” noted a conservation leader. “A significant shipping incident in the North Sea and the release of tonnes of plastic biobeads off the southern coast were serious issues. Dedicated individuals are working tirelessly to safeguard and rehabilitate our coasts.”