2025 Hailed as The Year for Octopuses Along England's South Coast.

Exceptionally high encounters of one of the world's most intelligent invertebrates over the summer months have resulted in the declaration of 2025 as the year for octopuses in an annual review of UK coastal waters.

A Confluence of Factors for a Population Boom

A mild winter followed by a remarkably hot spring prompted unprecedented numbers of common octopuses (*Octopus vulgaris*) to take up residence along the shores from Cornwall to Devon, across the southwestern peninsula.

“The volume of octopuses caught was of the order of about over a dozen times what we would normally expect in the waters around Cornwall,” commented a marine conservation officer. “Calculating the figures, approximately 233,000 octopuses were caught in British seas this year – representing a massive jump from historical averages.”

*Octopus vulgaris* is indigenous to these waters but typically so rare it is rarely seen. A sudden increase is caused by a combination of a mild winter and favorable spring temperatures. This perfect scenario meant more larvae, maybe aided by significant populations of spider crabs also recorded.

A Historic Event

The last time, such an octopus proliferation comparable was observed in 1950, with historical records indicating the one before that was in 1900.

The remarkable abundance of octopuses meant they could be frequently seen in nearshore environments for the first time in living memory. Video footage show octopuses gathering in groups – they are usually solitary – and “walking” along the ocean floor on their arm ends. One individual was even filmed grabbing submarine recording equipment.

“The first time I dived off the Lizard peninsula this year I saw five octopuses,” the officer added. “And these are big. We have two species in these waters. The curled octopus is rather small, football-sized, but these common octopuses can be up to a metre and a half wide.”

Looking Ahead & Coastal Highlights

If conditions remain mild heading into next year meant it was possible a second bloom the following year, because historically, in similar situations, events have occurred consecutively for two years in a row.

“But, it's improbable, based on past events, that it will persist indefinitely,” they said. “But the sea keeps giving us surprises at the moment so it’s a very uncertain scenario.”

The report also celebrated additional positive marine news around the UK coastline, including:

• Unprecedented numbers of grey seals recorded in Cumbria.
• Record numbers of puffins on an island off Wales.
• The first recording of the *Capellinia fustifera* nudibranch in a northern county, typically a southwestern species.
• A variable blenny spotted off the coast of Sussex for the first time.

A Note of Caution

The year had its low points, however. “The year was bookended by environmental disasters,” said a head of marine conservation. “A major tanker collision in the North Sea and the release of plastic pollution off the southern coast served as stark reminders. Conservation teams are making huge efforts to defend and heal our marine habitats.”