2025 Declared The Year for Octopuses Off Britain's Southern Shores.
Record-breaking observations of one of the world's most intelligent invertebrates during the summer season have resulted in the declaration of 2025 as the octopus's year in an annual review of UK coastal waters.
Ideal Conditions for a Population Boom
An unusually warm winter and then a remarkably hot spring catalyzed a huge population of common octopuses (*Octopus vulgaris*) to establish themselves along the southern coastline of England, spanning the Cornish and Devonian coasts.
“The scale of the catch was approximately thirteen times what we would typically see in this region,” commented an ocean conservation expert. “When we added up the numbers, around 233 thousand octopuses were present in British seas this year – that’s a huge increase from historical averages.”
*Octopus vulgaris* is indigenous to these waters but usually so scarce it is infrequently encountered. A sudden increase is caused by a combination of a mild winter and a warm breeding season. Such favorable circumstances meant increased juvenile survival, possibly in part fuelled by large numbers of a favored prey species seen in the area.
A Rare Phenomenon
Previously, an octopus bloom this significant was documented in 1950, with archival data indicating the one before that was in 1900.
The huge numbers of octopuses meant they could be readily observed in nearshore environments for the first time in living memory. Diver videos show octopuses gathering in groups – contrary to their normally lone nature – and “walking” along the seabed on the tips of their limbs. A curious octopus was even seen investigating an underwater camera.
“The first time I dived there this year I saw multiple octopuses,” the officer added. “They are sizeable. Two kinds exist in the region. One species is rather small, about the size of a football, but the *Octopus vulgaris* can be up to a metre and a half wide.”
Looking Ahead & Coastal Highlights
Another mild winter heading into next year could lead to a repeat event next year, because based on records, under these conditions, the blooms have repeated for two years running.
“Still, the chances are low, from previous blooms, that it will persist indefinitely,” they stated. “Marine life is unpredictable at the moment so it’s hard to forecast.”
The report also noted further encouraging coastal sightings across British shores, including:
- Highest-ever counts of gray seals seen in Cumbria.
- Peak numbers of puffins on Skomer.
- The initial discovery of a rare sea slug in a northern county, typically a southwestern species.
- A Mediterranean fish species found off the coast of Sussex for the inaugural time.
A Note of Caution
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 March and the release of plastic pollution off the southern coast highlighted ongoing threats. Conservation teams are working tirelessly to defend and heal our coasts.”
