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

Exceptionally high observations of a remarkably clever cephalopod this past summer have resulted in the designation of 2025 as the octopus's year in a yearly report of Britain’s seas.

A Confluence of Factors Driving a Surge

An unusually warm winter and then a remarkably hot spring triggered 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 scale of the catch was approximately over a dozen times what we would normally expect in Cornish waters,” commented a marine conservation officer. “Based on the totals, approximately 233,000 octopuses were found in UK waters this year – which is a significant rise from what is typical.”

*Octopus vulgaris* is found in these waters but ordinarily in such small numbers it is rarely seen. A population bloom is attributed to a combination of a mild winter and a warm breeding season. This perfect scenario meant more larvae, possibly in part fuelled by abundant stocks of other marine life noted in recent years.

A Historic Event

The most recent occasion, an octopus bloom this significant was observed in the mid-20th century, with archival data indicating the last bloom prior to that happened in 1900.

The huge numbers of octopuses meant they could be easily spotted in shallow waters for a rare occurrence. Video footage show octopuses congregating together – unlike their typical solitary behavior – and ambulating along the seabed on the tips of their limbs. One individual was even filmed grabbing submarine recording equipment.

“On my initial dive in that area this year I saw five of these creatures,” they noted. “They are sizeable. There are two types in UK waters. The curled octopus is smaller, the size of a ball, but these common octopuses can be with a span of 1.5 meters.”

Looking Ahead & Coastal Highlights

Another mild winter heading into next year meant it was possible another surge next year, because in the past, with such patterns, the blooms have repeated for two consecutive years.

“Still, the chances are low, based on past events, that it will go on for a long time,” they said. “But the sea keeps giving us surprises these days so it’s hard to forecast.”

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

• A record number of grey seals seen in one northern region.
• Exceptional populations of puffins on an island off Wales.
• The initial discovery of a rare sea slug in Yorkshire, typically a southwestern species.
• A type of blenny spotted off the coast of a southern county for the first occasion.

Not All Positive News

Challenges were also present, however. “The year was bookended by environmental disasters,” said a head of marine conservation. “A significant shipping incident in March and the release of tonnes of plastic biobeads off the Sussex coast served as stark reminders. Staff and volunteers are working tirelessly to safeguard and rehabilitate our coasts.”