2025 Declared The Year for Octopuses Off Britain's South Coast.
Record-breaking observations of a supremely intelligent sea creature during the summer season have led to the designation of 2025 as the octopus's year in an annual review of UK coastal waters.
A Perfect Storm for a Population Boom
A gentle winter and then a remarkably hot spring catalyzed a huge population of *Octopus vulgaris* to establish themselves along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.
“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 conservation officer. “Based on the totals, approximately 233,000 octopuses were caught in these waters this year – that’s a huge increase from the norm.”
*Octopus vulgaris* is found in British seas but usually so scarce it is rarely seen. An explosive growth is the result of the dual effect of a mild winter and favorable spring temperatures. This perfect scenario meant increased juvenile survival, maybe aided by abundant stocks of spider crabs also recorded.
A Historic Event
The last time, a population surge of this scale this significant was recorded in 1950, with archival data indicating the one before that was in 1900.
The huge numbers of octopuses meant they could be frequently seen in coastal areas for the first time in living memory. Underwater recordings show octopuses gathering in groups – they are usually solitary – and moving along the seabed on their arm ends. One creature was even seen investigating submarine recording equipment.
“The first time I dived there this year I saw five of these creatures,” the specialist continued. “They are sizeable. Two kinds exist in UK waters. The curled octopus is quite small, about the size of a football, but the *Octopus vulgaris* can be reaching impressive sizes.”
Future Prospects and Other Surprises
If conditions remain mild going into 2026 suggests the potential another surge next year, because based on records, in similar situations, populations have surged again for two years in a row.
“However, it is unlikely, looking at history, that it will go on for a long time,” they cautioned. “Marine life is unpredictable at the moment so it’s hard to forecast.”
The report also celebrated other “surprises, successes and joyful moments” around the UK coastline, including:
- Unprecedented numbers of grey seals observed in one northern region.
- Peak numbers of puffins on a Welsh island.
- A first-ever sighting of the *Capellinia fustifera* nudibranch in a northern county, usually found in the south-west.
- A variable blenny spotted off the coast of a southern county for the inaugural time.
Not All Positive News
Not everything was good news, however. “The year was bookended by environmental disasters,” noted a conservation leader. “A significant shipping incident in the North Sea and the release of tonnes of plastic biobeads off the southern coast were serious issues. Dedicated individuals are making huge efforts to protect and restore our coasts.”