2025 Declared The Year for Octopuses Off Britain's Southern Shores.

Exceptionally high sightings of one of the world's most intelligent invertebrates over the summer months have prompted the declaration of 2025 as “the year of the octopus” in an annual review of Britain’s seas.

A Perfect Storm Leading to an Explosion

A mild winter coupled with an exceptionally warm spring prompted a huge population of Mediterranean octopuses to establish themselves along the shores from Cornwall to Devon, across the southwestern peninsula.

“The volume of octopuses caught was approximately over a dozen times what we would usually anticipate in Cornish waters,” commented a marine life specialist. “Calculating the figures, approximately 233,000 octopuses were present in British seas this year – which is a significant rise from what is typical.”

*Octopus vulgaris* is indigenous to British seas but ordinarily in such small numbers it is infrequently encountered. A sudden increase is caused by the dual effect of a mild winter and a warm breeding season. This perfect scenario meant increased juvenile survival, possibly in part fuelled by large numbers of spider crabs noted in recent years.

A Rare Phenomenon

The most recent occasion, an octopus bloom of this size was recorded in 1950, with past documentation indicating the one before that was in 1900.

The remarkable abundance of octopuses meant they could be frequently seen in nearshore environments for a rare occurrence. Underwater recordings show octopuses congregating together – they are usually solitary – and ambulating along the ocean floor on their arm ends. One creature was even seen investigating an underwater camera.

“On my initial dive in that area this year I saw five of these creatures,” the officer added. “And these are big. There are two types in these waters. The curled octopus is rather small, about the size of a football, but the *Octopus vulgaris* can be up to a metre and a half wide.”

Predictions and Marine Joy

Another mild winter this coming winter suggests the potential another surge in 2026, because historically, with such patterns, the blooms have repeated for two consecutive years.

“However, it is unlikely, looking at history, that it will become a permanent fixture,” they cautioned. “The ocean is full of surprises these days so it’s a very uncertain scenario.”

The annual review also celebrated additional positive marine news along the coast, including:

• A record number of gray seals recorded in one northern region.
• Exceptional populations of the iconic seabirds on a Welsh island.
• The first recording of an unusual mollusc in Yorkshire, typically a southwestern species.
• A variable blenny discovered off the coast of Sussex for the first occasion.

Environmental Concerns

The year had its low points, however. “The calendar year was marked by marine incidents,” said a head of marine conservation. “A significant shipping incident in the North Sea and an accidental discharge of tonnes of plastic biobeads off the southern coast were serious issues. Staff and volunteers are putting in immense work to protect and restore our marine habitats.”