2025 Hailed as the 'Year of the Octopus' Off Britain's South Coast.

Unprecedented sightings of one of the world's most intelligent invertebrates over the summer months have resulted in the naming of 2025 as the year for octopuses in a seasonal assessment of Britain’s seas.

A Perfect Storm Driving a Surge

An unusually warm winter coupled with an exceptionally warm spring prompted a huge population of common octopuses (*Octopus vulgaris*) to take up residence along the southern coastline of England, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was roughly over a dozen times what we would normally expect in this region,” stated an ocean conservation expert. “Calculating the figures, approximately 233,000 octopuses were found in UK waters this year – that’s a huge increase from what is typical.”

The Mediterranean octopus is native to these waters but ordinarily in such small numbers it is infrequently encountered. A population bloom is caused by a combination of a mild winter and favorable spring temperatures. Such favorable circumstances meant increased juvenile survival, maybe aided by significant populations of spider crabs also recorded.

An Uncommon Occurrence

Previously, a population surge of this scale comparable was recorded in 1950, with archival data indicating the one before that occurred in 1900.

The huge numbers of octopuses meant they could be easily spotted in shallow waters for the first time in living memory. Underwater recordings show octopuses being sociable – contrary to their normally lone nature – and moving along the seabed on their arm ends. One creature was even seen investigating an underwater camera.

“The first time I dived there this year I saw multiple octopuses,” the officer added. “They are large specimens. There are two types in these waters. The curled octopus is quite small, about the size of a football, but these newcomers can be up to a metre and a half wide.”

Future Prospects and Other Surprises

A second gentle winter going into 2026 could lead to a repeat event next year, because historically, in similar situations, the blooms have repeated for two years running.

“Still, the chances are low, based on past events, that it will go on for a long time,” they cautioned. “The ocean is full of surprises currently so it’s a very uncertain scenario.”

The annual review also highlighted other “surprises, successes and joyful moments” around the UK coastline, including:

• Highest-ever counts of grey seals recorded in one northern region.
• Peak numbers of the iconic seabirds on a Welsh island.
• The initial discovery of an unusual mollusc in Yorkshire, usually found in the south-west.
• A variable blenny discovered off the coast of a southern county for the first time.

Environmental Concerns

The year had its low points, however. “The period was framed by marine incidents,” said a head of marine conservation. “A major tanker collision in the North Sea and the release of industrial pellets off the southern coast were serious issues. Conservation teams are making huge efforts to safeguard and rehabilitate our shorelines.”