2025 Declared the 'Year of the Octopus' Off England's South Coast.

Exceptionally high sightings of one of the world's most intelligent invertebrates during the summer season have led to the declaration of 2025 as the year for octopuses in a yearly report of Britain’s seas.

Ideal Conditions Driving a Surge

A mild winter followed by a remarkably hot spring catalyzed unprecedented numbers of Mediterranean octopuses to settle along the southern coastline of England, from Penzance in Cornwall to south Devon.

“The reported landings was approximately 13 times what we would usually anticipate in Cornish waters,” explained a marine life specialist. “Based on the totals, nearly a quarter of a million octopuses were found in British seas this year – that’s a huge increase from the norm.”

*Octopus vulgaris* is found in British seas but usually so scarce it is infrequently encountered. A sudden increase is attributed to the dual effect of gentle winter conditions and a warm breeding season. These ideal conditions meant increased juvenile survival, possibly in part fuelled by large numbers of spider crabs also recorded.

A Historic Event

The last time, a population surge of this scale comparable was documented in 1950, with archival data indicating the last bloom prior to that occurred in the turn of the 20th century.

The sheer quantity of octopuses meant they could be readily observed in nearshore environments for the first time in recent history. Diver videos show octopuses congregating together – contrary to their normally lone nature – and ambulating along the ocean floor on their tentacle tips. One creature was even recorded reaching for an underwater camera.

“The first time I dived in that area this year I saw five of these creatures,” the specialist continued. “And these are big. We have two species in UK waters. One species is rather small, about the size of a football, but these common octopuses can be reaching impressive sizes.”

Predictions and Marine Joy

Another mild winter heading into next year meant it was possible a second bloom in 2026, because in the past, under these conditions, populations have surged again for two years in a row.

“Still, the chances are low, from previous blooms, that it will persist indefinitely,” they said. “But the sea keeps giving us surprises currently so it’s a very uncertain scenario.”

The report also noted further encouraging coastal sightings across British shores, including:

• Highest-ever counts of grey seals observed in one northern region.
• Record numbers of the iconic seabirds on an island off Wales.
• A first-ever sighting of an unusual mollusc in Yorkshire, typically a southwestern species.
• A variable blenny discovered off the coast of a southern county for the first time.

A Note of Caution

The year had its low points, however. “The year was bookended by environmental disasters,” noted a conservation leader. “A major tanker collision in the North Sea and the release of tonnes of plastic biobeads off the Sussex coast served as stark reminders. Dedicated individuals are making huge efforts to protect and restore our coasts.”