2025 Proclaimed the 'Year of the Octopus' Along Britain's Southern Shores.

Record-breaking sightings of one of the world's most intelligent invertebrates this past summer have prompted the naming of 2025 as “the year of the octopus” in an annual review of UK coastal waters.

A Confluence of Factors Driving a Surge

An unusually warm winter coupled with a remarkably hot spring triggered a massive influx 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 approximately over a dozen times what we would normally expect in the waters around Cornwall,” stated a marine conservation officer. “Based on the totals, around 233 thousand octopuses were caught in these waters this year – that’s a huge increase from the norm.”

The Mediterranean octopus is found in these waters but usually so scarce it is infrequently encountered. An explosive growth is caused by a combination of gentle winter conditions and a warm breeding season. This perfect scenario meant more larvae, potentially supported by significant populations of spider crabs noted in recent years.

A Rare Phenomenon

The last time, an octopus bloom of this size was documented in the mid-20th century, with past documentation indicating the previous major event was in the turn of the 20th century.

The huge numbers of octopuses meant they could be frequently seen in nearshore environments for the first time in living memory. Video footage show octopuses being sociable – contrary to their normally lone nature – and “walking” along the bottom on their arm ends. One creature was even seen investigating submarine recording equipment.

“During a first dive off the Lizard peninsula this year I saw five of these creatures,” the officer added. “They are large specimens. There are two types in these waters. One species 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 going into 2026 meant it was possible a repeat event next year, because based on records, with such patterns, events have occurred consecutively for two years running.

“But, it's improbable, looking at history, that it will persist indefinitely,” they cautioned. “Marine life is unpredictable currently so it’s quite an unpredictable situation.”

The annual review also highlighted further encouraging coastal sightings around the UK coastline, including:

• A record number of grey seals seen in Cumbria.
• Record numbers of the iconic seabirds on a Welsh island.
• The initial discovery of a rare sea slug in a northern county, typically a southwestern species.
• A variable blenny discovered off the coast of Sussex for the first occasion.

A Note of Caution

Challenges were also present, however. “The calendar year was marked by ecological challenges,” stated an expert. “A significant shipping incident in March and an accidental discharge of tonnes of plastic biobeads off the Sussex coast highlighted ongoing threats. Staff and volunteers are putting in immense work to protect and restore our shorelines.”