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

Unprecedented observations of a remarkably clever cephalopod this past summer have prompted the declaration of 2025 as “the year of the octopus” in a seasonal assessment of Britain’s seas.

A Perfect Storm Driving a Surge

A mild winter and then a very warm springtime catalyzed a massive influx of Mediterranean octopuses to settle along the shores from Cornwall to Devon, across the southwestern peninsula.

“The scale of the catch was approximately 13 times what we would usually anticipate in this region,” stated an ocean conservation expert. “When we added up the numbers, approximately 233,000 octopuses were present in UK waters this year – that’s a huge increase from what is typical.”

The common octopus is found in UK waters but ordinarily in such small numbers it is seldom observed. An explosive growth is the result of a combination of a mild winter and favorable spring temperatures. This perfect scenario meant more larvae, possibly in part fuelled by large numbers of a favored prey species seen in the area.

An Uncommon Occurrence

The most recent occasion, a population surge of this scale of this size was observed in the mid-20th century, with archival data indicating the previous major event happened in 1900.

The remarkable abundance of octopuses meant they could be frequently seen in shallow waters for the first time in living memory. Diver videos show octopuses congregating together – unlike their typical solitary behavior – and ambulating along the seabed on their tentacle tips. One creature was even recorded reaching for submarine recording equipment.

“During a first dive there this year I saw five of these creatures,” the officer added. “And these are big. We have two species in these waters. One species is smaller, football-sized, but these common octopuses can be with a span of 1.5 meters.”

Future Prospects and Other Surprises

A second gentle winter this coming winter could lead to a second bloom the following year, because historically, under these conditions, events have occurred consecutively for two consecutive years.

“Still, the chances are low, based on past events, that it will become a permanent fixture,” they said. “Marine life is unpredictable at the moment so it’s quite an unpredictable situation.”

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

• Highest-ever counts of grey seals observed in one northern region.
• Peak numbers of the iconic seabirds on a Welsh island.
• A first-ever sighting of an unusual mollusc in Yorkshire, normally residing farther south.
• A Mediterranean fish species spotted off the coast of a southern county for the first occasion.

Environmental Concerns

Challenges were also present, however. “The year was bookended by marine incidents,” said a head of marine conservation. “A major tanker collision in the North Sea and the release of plastic pollution off the southern coast were serious issues. Conservation teams are making huge efforts to safeguard and rehabilitate our coasts.”