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

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

A Confluence of Factors Leading to an Explosion

A gentle winter and then an exceptionally warm spring prompted unprecedented numbers of *Octopus vulgaris* to take up residence along England’s south coast, from Penzance in Cornwall to south Devon.

“The volume of octopuses caught was of the order of about over a dozen times what we would typically see in Cornish waters,” stated a marine life specialist. “Based on the totals, nearly a quarter of a million octopuses were present in UK waters this year – which is a significant rise from historical averages.”

The common octopus is native to UK waters but usually so scarce it is rarely seen. An explosive growth is the result of a combination of a mild winter and a warm breeding season. This perfect scenario meant a higher survival rate for young, maybe aided by significant populations of other marine life seen in the area.

A Rare Phenomenon

The last time, such an octopus proliferation this significant was documented in the 1950s, with past documentation indicating the last bloom prior to that was in the turn of the 20th century.

The sheer quantity of octopuses meant they could be easily spotted in coastal areas for the first time in living memory. Underwater recordings show octopuses being sociable – they are usually solitary – and ambulating along the ocean floor on the tips of their limbs. One creature was even recorded reaching for a diver's camera.

“The first time I dived in that area this year I saw five of these creatures,” they noted. “And these are big. There are two types in UK waters. The curled octopus is quite small, about the size of a football, but these newcomers can be reaching impressive sizes.”

Looking Ahead & Coastal Highlights

Another mild winter going into 2026 meant it was possible another surge in 2026, because in the past, in similar situations, the blooms have repeated for two years running.

“Still, the chances are low, based on past events, that it will go on for a long time,” they said. “The ocean is full of surprises currently so it’s a very uncertain scenario.”

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

• Highest-ever counts of grey seals recorded in Cumbria.
• Exceptional populations of the iconic seabirds on an island off Wales.
• A first-ever sighting of a rare sea slug in Yorkshire, usually found in the south-west.
• A type of blenny found 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,” noted a conservation leader. “A significant shipping incident in the North Sea and a spill of tonnes of plastic biobeads off the southern coast highlighted ongoing threats. Dedicated individuals are making huge efforts to protect and restore our marine habitats.”