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

Record-breaking encounters of one of the world's most intelligent invertebrates this past summer have led to the designation of 2025 as the year for octopuses in an annual review of the nation's marine environment.

Ideal Conditions for a Population Boom

A mild winter followed by a very warm springtime prompted unprecedented numbers of common octopuses (*Octopus vulgaris*) to settle along the southern coastline of England, across the southwestern peninsula.

“The reported landings was approximately over a dozen times what we would normally expect in Cornish waters,” stated a marine life specialist. “Calculating the figures, around 233 thousand octopuses were found in UK waters this year – representing a massive jump from the norm.”

The Mediterranean octopus is indigenous to British seas 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 a higher survival rate for young, possibly in part fuelled by abundant stocks of a favored prey species also recorded.

A Historic Event

Previously, an octopus bloom this significant was observed in the 1950s, with archival data indicating the previous major event was in the turn of the 20th century.

The huge numbers of octopuses meant they could be easily spotted in coastal areas for a rare occurrence. Video footage show octopuses being sociable – they are usually solitary – and “walking” along the ocean floor on their arm ends. A curious octopus was even recorded reaching for an underwater camera.

“The first time I dived off the Lizard peninsula this year I saw five octopuses,” they noted. “They are sizeable. We have two species in the region. One species is rather small, the size of a ball, 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 could lead to another surge in 2026, because in the past, in similar situations, populations have surged again for two consecutive years.

“Still, the chances are low, from previous blooms, that it will persist indefinitely,” they stated. “The ocean is full of surprises these days so it’s quite an unpredictable situation.”

The annual review also highlighted other “surprises, successes and joyful moments” across British shores, including:

• Highest-ever counts of grey seals observed in one northern region.
• Record numbers of the iconic seabirds on Skomer.
• The initial discovery of a rare sea slug in a northern county, usually found in the south-west.
• A type of blenny spotted off the coast of Sussex for the first time.

A Note of Caution

Not everything was good news, however. “The calendar year was marked by marine incidents,” said a head of marine conservation. “A significant shipping incident in March and a spill of industrial pellets off the Sussex coast highlighted ongoing threats. Staff and volunteers are putting in immense work to defend and heal our shorelines.”