2025 Hailed as 'The Octopus Year' Off England's South Coast.

Exceptionally high sightings of one of the world's most intelligent invertebrates over the summer months have led to the naming of 2025 as the octopus's year in a yearly report of the nation's marine environment.

A Confluence of Factors Driving a Surge

An unusually warm winter and then an exceptionally warm spring prompted unprecedented numbers of common octopuses (*Octopus vulgaris*) to settle along the shores from Cornwall to Devon, across the southwestern peninsula.

“The reported landings was approximately 13 times what we would usually anticipate in this region,” commented a marine conservation officer. “Calculating the figures, around 233 thousand octopuses were found in these waters this year – that’s a huge increase from the norm.”

*Octopus vulgaris* is indigenous to UK waters but usually so scarce it is rarely seen. A sudden increase is caused by the dual effect of a mild winter and favorable spring temperatures. This perfect scenario meant increased juvenile survival, potentially supported by abundant stocks of spider crabs noted in recent years.

A Rare Phenomenon

Previously, such an octopus proliferation this significant was documented in the 1950s, with past documentation indicating the last bloom prior to that happened in 1900.

The huge numbers of octopuses meant they could be easily spotted in nearshore environments for a rare occurrence. Diver videos show octopuses gathering in groups – unlike their typical solitary behavior – and ambulating along the ocean floor on their tentacle tips. One creature was even recorded reaching for submarine recording equipment.

“During a first dive off the Lizard peninsula this year I saw five of these creatures,” the specialist continued. “And these are big. We have two species in these waters. The curled octopus is smaller, the size of a ball, but these common octopuses can be up to a metre and a half wide.”

Future Prospects and Other Surprises

Another mild winter going into 2026 suggests the potential a repeat event in 2026, because based on records, under these conditions, the blooms have repeated for two consecutive years.

“But, it's improbable, from previous blooms, that it will go on for a long time,” they cautioned. “But the sea keeps giving us surprises these days so it’s quite an unpredictable situation.”

The report also celebrated other “surprises, successes and joyful moments” around the UK coastline, including:

• Highest-ever counts of grey seals observed in one northern region.
• Peak numbers of the iconic seabirds on a Welsh island.
• The initial discovery of the *Capellinia fustifera* nudibranch in Yorkshire, normally residing farther south.
• A type of blenny discovered off the coast of a southern county for the inaugural time.

A Note of Caution

Not everything was good news, however. “The calendar year was marked 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 Sussex coast highlighted ongoing threats. Staff and volunteers are making huge efforts to protect and restore our coasts.”