2025 Proclaimed 'The Octopus Year' Along England's South Coast.
Exceptionally high observations of one of the world's most intelligent invertebrates this past summer have prompted the designation of 2025 as the octopus's year in a seasonal assessment of Britain’s seas.
A Confluence of Factors Driving a Surge
A mild winter followed by a very warm springtime prompted a massive influx of *Octopus vulgaris* to settle along the southern coastline of England, from Penzance in Cornwall to south Devon.
“The scale of the catch was of the order of about 13 times what we would typically see in the waters around Cornwall,” stated a marine life specialist. “When we added up the numbers, approximately 233,000 octopuses were found in British seas this year – that’s a huge increase from historical averages.”
*Octopus vulgaris* is indigenous to British seas but usually so scarce it is infrequently encountered. A population bloom is the result of the dual effect of a mild winter and favorable spring temperatures. These ideal conditions meant more larvae, potentially supported by large numbers of other marine life seen in the area.
A Historic Event
Previously, a population surge of this scale of this size was recorded in 1950, with archival data indicating the last bloom prior to that occurred in the turn of the 20th century.
The huge numbers of octopuses meant they could be frequently seen in shallow waters for the first time in living memory. Diver videos show octopuses being sociable – unlike their typical solitary behavior – and moving along the ocean floor on the tips of their limbs. One individual was even seen investigating an underwater camera.
“The first time I dived in that area this year I saw five of these creatures,” the officer added. “They are sizeable. There are two types in UK waters. One species is quite small, about the size of a football, but the *Octopus vulgaris* can be reaching impressive sizes.”
Future Prospects and Other Surprises
Another mild winter going into 2026 suggests the potential 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, from previous blooms, that it will persist indefinitely,” they cautioned. “The ocean is full of surprises at the moment so it’s a very uncertain scenario.”
The assessment also highlighted other “surprises, successes and joyful moments” around the UK coastline, including:
- A record number of gray seals observed in one northern region.
- Exceptional populations of the iconic seabirds on Skomer.
- The first recording of the *Capellinia fustifera* nudibranch in Yorkshire, usually found in the south-west.
- A type of blenny discovered off the coast of Sussex for the first occasion.
Environmental Concerns
The year had its low points, however. “The period was framed by marine incidents,” said a head of marine conservation. “A significant shipping incident in the North Sea and the release of plastic pollution off the Sussex coast highlighted ongoing threats. Staff and volunteers are putting in immense work to defend and heal our coasts.”