2025 Proclaimed 'The Octopus Year' Off Britain's Southern Shores.

Exceptionally high sightings of a remarkably clever cephalopod this past summer have prompted the declaration of 2025 as the octopus's year in a yearly report of the nation's marine environment.

A Confluence of Factors for a Population Boom

A gentle winter coupled with a very warm springtime catalyzed unprecedented numbers of Mediterranean octopuses to establish themselves along the southern coastline of England, from Penzance in Cornwall to south Devon.

“The volume of octopuses caught was approximately 13 times what we would usually anticipate in this region,” explained a marine conservation officer. “Calculating the figures, approximately 233,000 octopuses were found in UK waters this year – that’s a huge increase from the norm.”

*Octopus vulgaris* is found in British seas but ordinarily in such small numbers it is seldom observed. A population bloom is attributed to a combination of a mild winter and favorable spring temperatures. These ideal conditions meant more larvae, maybe aided by significant populations of spider crabs also recorded.

A Historic Event

The most recent occasion, an octopus bloom comparable was documented in 1950, with historical records indicating the previous major event was in 1900.

The sheer quantity of octopuses meant they could be frequently seen in shallow waters for the first time in living memory. Diver videos show octopuses being sociable – they are usually solitary – and “walking” along the seabed on the tips of their limbs. A curious octopus was even filmed grabbing a diver's camera.

“On my initial dive off the Lizard peninsula this year I saw five of these creatures,” the specialist continued. “They are sizeable. We have two species in the region. One species is quite small, the size of a ball, but these common octopuses can be reaching impressive sizes.”

Looking Ahead & Coastal Highlights

Another mild 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 years in a row.

“However, it is unlikely, based on past events, that it will persist indefinitely,” they cautioned. “Marine life is unpredictable currently so it’s quite an unpredictable situation.”

The assessment also celebrated additional positive marine news along the coast, including:

• Unprecedented numbers of gray seals observed in one northern region.
• Exceptional populations of puffins on a Welsh island.
• The initial discovery of a rare sea slug in Yorkshire, normally residing farther south.
• A type of blenny spotted off the coast of a southern county for the first occasion.

A Note of Caution

Not everything was good news, however. “The period was framed by marine incidents,” said a head of marine conservation. “A major tanker collision in March and a spill of tonnes of plastic biobeads off the southern coast served as stark reminders. Staff and volunteers are making huge efforts to protect and restore our shorelines.”