2025 Proclaimed the 'Year of the Octopus' Off Britain's South Coast.

Exceptionally high observations of a remarkably clever cephalopod during the summer season have led to the declaration of 2025 as “the year of the octopus” in an annual review of Britain’s seas.

A Confluence of Factors for a Population Boom

A mild winter and then a very warm springtime prompted a huge population of common octopuses (*Octopus vulgaris*) to settle along the southern coastline of England, spanning the Cornish and Devonian coasts.

“The scale of the catch was of the order of about 13 times what we would normally expect in Cornish waters,” commented an ocean conservation expert. “When we added up the numbers, nearly a quarter of a million octopuses were present in UK waters this year – which is a significant rise from what is typical.”

*Octopus vulgaris* is native to UK waters but ordinarily in such small numbers it is infrequently encountered. A population bloom is caused by a combination of a mild winter and a warm breeding season. These ideal conditions meant more larvae, maybe aided by abundant stocks of a favored prey species also recorded.

A Historic Event

Previously, such an octopus proliferation of this size was observed in 1950, with archival data indicating the one before that was in 1900.

The sheer quantity of octopuses meant they could be readily observed in shallow waters for the first time in recent history. Underwater recordings show octopuses being sociable – unlike their typical solitary behavior – and ambulating along the seabed on the tips of their limbs. One individual was even seen investigating an underwater camera.

“During a first dive there this year I saw multiple octopuses,” the specialist continued. “They are large specimens. There are two types in UK waters. The curled octopus is smaller, about the size of a football, but the *Octopus vulgaris* can be with a span of 1.5 meters.”

Future Prospects and Other Surprises

If conditions remain mild heading into next year suggests the potential another surge in 2026, because based on records, with such patterns, the blooms have repeated for two consecutive years.

“Still, the chances are low, based on past events, that it will become a permanent fixture,” they cautioned. “Marine life is unpredictable currently so it’s a very uncertain scenario.”

The annual review also celebrated other “surprises, successes and joyful moments” along the coast, including:

• Unprecedented numbers of gray seals recorded in Cumbria.
• Record numbers of puffins on Skomer.
• The initial discovery of a rare sea slug in a northern county, normally residing farther south.
• A Mediterranean fish species found off the coast of a southern county for the first occasion.

Environmental Concerns

The year had its low points, however. “The period was framed by environmental disasters,” said a head of marine conservation. “A significant shipping incident in March and a spill of industrial pellets off the southern coast highlighted ongoing threats. Conservation teams are working tirelessly to defend and heal our coasts.”