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

Record-breaking encounters of a supremely intelligent sea creature over the summer months have prompted the naming of 2025 as “the year of the octopus” in an annual review of Britain’s seas.

Ideal Conditions Leading to an Explosion

A gentle winter coupled with an exceptionally warm spring prompted a massive influx of *Octopus vulgaris* to settle along the southern coastline of England, spanning the Cornish and Devonian coasts.

“The scale of the catch was roughly 13 times what we would normally expect in the waters around Cornwall,” stated a marine conservation officer. “Calculating the figures, around 233 thousand octopuses were present in UK waters this year – which is a significant rise from what is typical.”

*Octopus vulgaris* is found in UK waters but typically so rare it is rarely seen. A sudden increase is the result of a combination of gentle winter conditions and a warm breeding season. This perfect scenario meant more larvae, possibly in part fuelled by abundant stocks of spider crabs seen in the area.

An Uncommon Occurrence

The last time, a population surge of this scale of this size was documented in 1950, with past documentation indicating the one before that happened in 1900.

The huge numbers of octopuses meant they could be easily spotted in shallow waters for a rare occurrence. Underwater recordings show octopuses gathering in groups – unlike their typical solitary behavior – and moving along the ocean floor on their arm ends. One individual was even seen investigating an underwater camera.

“On my initial dive off the Lizard peninsula this year I saw multiple octopuses,” the officer added. “And these are big. We have two species in the region. One species is smaller, the size of a ball, but these newcomers can be reaching impressive sizes.”

Looking Ahead & Coastal Highlights

Another mild winter going into 2026 meant it was possible a second bloom the following year, because based on records, under these conditions, populations have surged again for two consecutive years.

“Still, the chances are low, looking at history, that it will become a permanent fixture,” they said. “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 around the UK coastline, including:

• A record number of grey seals seen in one northern region.
• Exceptional populations of the iconic seabirds on a Welsh island.
• A first-ever sighting of a rare sea slug in a northern county, normally residing farther south.
• A variable blenny discovered off the coast of Sussex for the first occasion.

A Note of Caution

Not everything was good news, however. “The period was framed by marine incidents,” noted a conservation leader. “A major tanker collision in March and the release of plastic pollution off the southern coast were serious issues. Staff and volunteers are working tirelessly to protect and restore our shorelines.”