2025 Proclaimed 'The Octopus Year' Along Britain's Southern Shores.
Exceptionally high encounters of a remarkably clever cephalopod over the summer months have prompted the declaration of 2025 as “the year of the octopus” in a seasonal assessment of the nation's marine environment.
A Perfect Storm for a Population Boom
A mild winter and then an exceptionally warm spring triggered a huge population of Mediterranean octopuses to establish themselves along the southern coastline of England, spanning the Cornish and Devonian coasts.
“The volume of octopuses caught was roughly thirteen times what we would normally expect in this region,” explained a marine life specialist. “Based on the totals, around 233 thousand octopuses were present in British seas this year – which is a significant rise from historical averages.”
The Mediterranean octopus is found in British seas but ordinarily in such small numbers it is seldom observed. An explosive growth is attributed to a combination of a mild winter and favorable spring temperatures. These ideal conditions meant a higher survival rate for young, maybe aided by large numbers of other marine life noted in recent years.
A Historic Event
Previously, a population surge of this scale this significant was observed in 1950, with historical records indicating the one before that happened in 1900.
The remarkable abundance of octopuses meant they could be frequently seen in shallow waters for the first time in living memory. Underwater recordings show octopuses being sociable – unlike their typical solitary behavior – and moving along the bottom on the tips of their limbs. One individual was even recorded reaching for a diver's camera.
“During a first dive there this year I saw five octopuses,” they noted. “They are sizeable. We have two species in the region. One species is smaller, about the size of a football, but the *Octopus vulgaris* can be reaching impressive sizes.”
Looking Ahead & Coastal Highlights
Another mild winter going into 2026 could lead to a second bloom next year, because based on records, with such patterns, populations have surged again for two consecutive years.
“Still, the chances are low, based on past events, that it will persist indefinitely,” they cautioned. “The ocean is full of surprises currently so it’s a very uncertain scenario.”
The assessment also celebrated further encouraging coastal sightings around the UK coastline, including:
- A record number of grey seals seen in Cumbria.
- Peak numbers of puffins on Skomer.
- The first recording of the *Capellinia fustifera* nudibranch in a northern county, typically a southwestern species.
- A Mediterranean fish species spotted off the coast of a southern county for the first occasion.
Not All Positive News
The year had its low points, however. “The year was bookended by marine incidents,” said a head of marine conservation. “A significant shipping incident in the North Sea and a spill of plastic pollution off the southern coast were serious issues. Staff and volunteers are putting in immense work to defend and heal our coasts.”