2025 Declared the 'Year of the Octopus' Off Britain's Southern Shores.

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

Ideal Conditions for a Population Boom

A mild winter followed by a remarkably hot spring catalyzed unprecedented numbers of common octopuses (*Octopus vulgaris*) to take up residence along the southern coastline of England, from Penzance in Cornwall to south Devon.

“The reported landings was approximately thirteen times what we would normally expect in Cornish waters,” explained a marine conservation officer. “Based on the totals, approximately 233,000 octopuses were caught in these waters this year – which is a significant rise from historical averages.”

The Mediterranean octopus is found in these waters but ordinarily in such small numbers it is infrequently encountered. A sudden increase is caused by a combination of a mild winter and a warm breeding season. Such favorable circumstances meant a higher survival rate for young, maybe aided by large numbers of a favored prey species also recorded.

A Rare Phenomenon

The most recent occasion, an octopus bloom of this size was recorded in the mid-20th century, with past documentation indicating the previous major event happened in 1900.

The sheer quantity of octopuses meant they could be easily spotted in coastal areas for the first time in living memory. Diver videos show octopuses gathering in groups – contrary to their normally lone nature – and “walking” along the seabed on their tentacle tips. One individual was even filmed grabbing an underwater camera.

“The first time I dived in that area this year I saw multiple octopuses,” the officer added. “And these are big. There are two types in UK waters. The curled octopus is smaller, the size of a ball, but these newcomers can be up to a metre and a half wide.”

Looking Ahead & Coastal Highlights

If conditions remain mild this coming winter meant it was possible a second bloom the following year, because based on records, with such patterns, the blooms have repeated for two consecutive years.

“However, it is unlikely, from previous blooms, that it will become a permanent fixture,” they said. “But the sea keeps giving us surprises these days so it’s quite an unpredictable situation.”

The annual review also highlighted other “surprises, successes and joyful moments” around the UK coastline, including:

• A record number of gray seals seen in Cumbria.
• Peak numbers of puffins on Skomer.
• The initial discovery of an unusual mollusc in a northern county, usually found in the south-west.
• A variable blenny discovered off the coast of a southern county for the inaugural time.

Environmental Concerns

Not everything was good news, however. “The calendar year was marked by ecological challenges,” said a head of marine conservation. “A major tanker collision in March and the release of plastic pollution off the Sussex coast highlighted ongoing threats. Dedicated individuals are working tirelessly to defend and heal our shorelines.”