2025 Hailed as the 'Year of the Octopus' Off England's South Coast.

Record-breaking encounters of a remarkably clever cephalopod this past summer have prompted the designation of 2025 as the octopus's year in a seasonal assessment of the nation's marine environment.

Ideal Conditions for a Population Boom

A mild winter followed by a remarkably hot spring catalyzed unprecedented numbers of common octopuses (*Octopus vulgaris*) to establish themselves along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.

“The reported landings was of the order of about over a dozen times what we would typically see in the waters around Cornwall,” stated a marine conservation officer. “When we added up the numbers, nearly a quarter of a million octopuses were caught in UK waters this year – that’s a huge increase from historical averages.”

The common octopus is found in British seas but usually so scarce it is infrequently encountered. A population bloom is caused by a combination of a mild winter and favorable spring temperatures. These ideal conditions meant a higher survival rate for young, maybe aided by significant populations of spider crabs seen in the area.

An Uncommon Occurrence

Previously, such an octopus proliferation this significant was documented in the 1950s, with historical records indicating the one before that was in the turn of the 20th century.

The remarkable abundance of octopuses meant they could be easily spotted in nearshore environments for the first time in living memory. Diver videos show octopuses being sociable – unlike their typical solitary behavior – and moving along the seabed on their tentacle tips. One individual was even recorded reaching for an underwater camera.

“During a first dive in that area this year I saw multiple octopuses,” the specialist continued. “And these are big. We have two species in UK waters. The curled octopus is rather small, about the size of a football, but these common octopuses can be reaching impressive sizes.”

Future Prospects and Other Surprises

A second gentle winter this coming winter could lead to a repeat event in 2026, because based on records, in similar situations, populations have surged again for two consecutive years.

“Still, the chances are low, looking at history, that it will persist indefinitely,” they stated. “But the sea keeps giving us surprises at the moment so it’s hard to forecast.”

The annual review also noted further encouraging coastal sightings along the coast, including:

• A record number of grey seals seen in one northern region.
• Exceptional populations of puffins on Skomer.
• A first-ever sighting of an unusual mollusc in a northern county, typically a southwestern species.
• A variable blenny spotted off the coast of a southern county for the first occasion.

A Note of Caution

Not everything was good news, however. “The year was bookended by marine incidents,” said a head of marine conservation. “A major tanker collision in the North Sea and the release of tonnes of plastic biobeads off the southern coast were serious issues. Staff and volunteers are putting in immense work to defend and heal our coasts.”