2025 Declared 'The Octopus Year' Along Britain's Southern Shores.

Unprecedented observations of a supremely intelligent sea creature over the summer months have prompted the declaration of 2025 as the year for octopuses in an annual review of Britain’s seas.

A Perfect Storm Driving a Surge

A gentle winter followed by an exceptionally warm spring triggered unprecedented numbers of common octopuses (*Octopus vulgaris*) to take up residence along England’s south coast, across the southwestern peninsula.

“The volume of octopuses caught was approximately 13 times what we would normally expect in Cornish waters,” stated a marine life specialist. “Calculating the figures, nearly a quarter of a million octopuses were caught in these waters this year – that’s a huge increase from historical averages.”

The common octopus is native to British seas but typically so rare it is infrequently encountered. A population bloom is caused by a combination of a mild winter and favorable spring temperatures. Such favorable circumstances meant more larvae, possibly in part fuelled by significant populations of spider crabs noted in recent years.

A Rare Phenomenon

The most recent occasion, an octopus bloom of this size was recorded in the 1950s, with archival data indicating the one before that occurred in 1900.

The sheer quantity of octopuses meant they could be frequently seen in nearshore environments for the first time in recent history. Diver videos show octopuses gathering in groups – unlike their typical solitary behavior – and ambulating along the ocean floor on their arm ends. A curious octopus was even seen investigating a diver's camera.

“On my initial dive in that area this year I saw five octopuses,” the specialist continued. “They are sizeable. There are two types in these waters. One species is rather small, about the size of a football, but these newcomers can be with a span of 1.5 meters.”

Future Prospects and Other Surprises

Another mild winter going into 2026 meant it was possible a second bloom next year, because in the past, under these conditions, populations have surged again for two years running.

“However, it is unlikely, based on past events, that it will persist indefinitely,” they stated. “But the sea keeps giving us surprises these days so it’s a very uncertain scenario.”

The report also noted additional positive marine news around the UK coastline, including:

• Unprecedented numbers of grey seals seen in one northern region.
• Peak numbers of the iconic seabirds on a Welsh island.
• The initial discovery of a rare sea slug in Yorkshire, normally residing farther south.
• A variable blenny found off the coast of Sussex for the first occasion.

Not All Positive News

The year had its low points, however. “The year was bookended by ecological challenges,” said a head of marine conservation. “A significant shipping incident in the North Sea and a spill of tonnes of plastic biobeads off the Sussex coast were serious issues. Dedicated individuals are working tirelessly to defend and heal our shorelines.”