2025 Declared The Year for Octopuses Off England's South Coast.

Unprecedented sightings of a supremely intelligent sea creature over the summer months have led to the designation of 2025 as the octopus's year in a yearly report of Britain’s seas.

A Perfect Storm Driving a Surge

An unusually warm winter followed by a very warm springtime prompted a massive influx of Mediterranean octopuses to establish themselves along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was of the order of about 13 times what we would typically see in the waters around Cornwall,” stated a marine conservation officer. “Calculating the figures, nearly a quarter of a million octopuses were found in British seas this year – representing a massive jump from the norm.”

The common octopus is found in British seas but usually so scarce it is seldom observed. An explosive growth is the result of the dual effect of a mild winter and a warm breeding season. Such favorable circumstances meant a higher survival rate for young, possibly in part fuelled by large numbers of other marine life also recorded.

An Uncommon Occurrence

Previously, such an octopus proliferation this significant was recorded in 1950, with past documentation indicating the one before that was in the turn of the 20th century.

The huge numbers of octopuses meant they could be frequently seen in nearshore environments for a rare occurrence. Diver videos show octopuses congregating together – contrary to their normally lone nature – and “walking” along the seabed on their arm ends. A curious octopus was even seen investigating a diver's camera.

“During a first dive off the Lizard peninsula this year I saw five of these creatures,” the specialist continued. “And these are big. Two kinds exist in these waters. One species is quite small, football-sized, but the *Octopus vulgaris* can be up to a metre and a half wide.”

Predictions and Marine Joy

A second gentle winter going into 2026 meant it was possible a second bloom the following year, because based on records, in similar situations, the blooms have repeated for two years in a row.

“But, it's improbable, looking at history, that it will persist indefinitely,” they cautioned. “But the sea keeps giving us surprises currently so it’s quite an unpredictable situation.”

The annual review also celebrated additional positive marine news across British shores, including:

• Highest-ever counts of gray seals seen in Cumbria.
• Record numbers of puffins on an island off Wales.
• The initial discovery of a rare sea slug in a northern county, usually found in the south-west.
• A Mediterranean fish species discovered off the coast of a southern county for the first occasion.

A Note of Caution

The year had its low points, however. “The period was framed by ecological challenges,” stated an expert. “A significant shipping incident in the North Sea and a spill of tonnes of plastic biobeads off the southern coast were serious issues. Conservation teams are working tirelessly to protect and restore our coasts.”