2025 Proclaimed the 'Year of the Octopus' Along England's South Coast.

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

A Perfect Storm Leading to an Explosion

An unusually warm winter and then a remarkably hot spring triggered unprecedented numbers of Mediterranean octopuses to take up residence along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was of the order of about over a dozen times what we would normally expect in Cornish waters,” stated a marine conservation officer. “Calculating the figures, approximately 233,000 octopuses were present in British seas this year – which is a significant rise from what is typical.”

The common octopus is native to UK waters but ordinarily in such small numbers it is infrequently encountered. A sudden increase is caused by a combination of gentle winter conditions and favorable spring temperatures. This perfect scenario meant more larvae, possibly in part fuelled by large numbers of spider crabs noted in recent years.

A Historic Event

Previously, an octopus bloom this significant was recorded in the 1950s, with past documentation indicating the one before that happened in 1900.

The remarkable abundance of octopuses meant they could be readily observed in coastal areas for the first time in recent history. Video footage show octopuses being sociable – contrary to their normally lone nature – and “walking” along the bottom on the tips of their limbs. One creature was even filmed grabbing submarine recording equipment.

“During a first dive in that area this year I saw five octopuses,” they noted. “And these are big. There are two types in these waters. The curled octopus is smaller, about the size of a football, but these common octopuses can be up to a metre and a half wide.”

Future Prospects and Other Surprises

If conditions remain mild going into 2026 could lead to another surge in 2026, because in the past, under these conditions, events have occurred consecutively for two years running.

“However, it is unlikely, looking at history, that it will become a permanent fixture,” they cautioned. “The ocean is full of surprises at the moment so it’s a very uncertain scenario.”

The annual review also noted additional positive marine news around the UK coastline, including:

• Highest-ever counts of gray seals recorded in one northern region.
• Exceptional populations 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 type of blenny found off the coast of a southern county for the inaugural time.

Environmental Concerns

The year had its low points, however. “The period was framed by environmental disasters,” said a head of marine conservation. “A major tanker collision in March and the release of plastic pollution off the Sussex coast served as stark reminders. Staff and volunteers are working tirelessly to safeguard and rehabilitate our shorelines.”