2025 Hailed as the 'Year of the Octopus' Off England's South Coast.

Record-breaking observations of a supremely intelligent sea creature over the summer months have resulted in the declaration of 2025 as the octopus's year in a yearly report of the nation's marine environment.

A Perfect Storm Leading to an Explosion

A gentle winter and then a very warm springtime triggered a huge population of Mediterranean octopuses to take up residence along the southern coastline of England, spanning the Cornish and Devonian coasts.

“The volume of octopuses caught was of the order of about over a dozen times what we would typically see in Cornish waters,” stated an ocean conservation expert. “When we added up the numbers, around 233 thousand octopuses were found in British seas this year – which is a significant rise from historical averages.”

*Octopus vulgaris* is native to UK waters but typically so rare it is rarely seen. An explosive growth is caused by a combination of gentle winter conditions and a warm breeding season. Such favorable circumstances meant more larvae, possibly in part fuelled by significant populations of other marine life also recorded.

An Uncommon Occurrence

The most recent occasion, an octopus bloom of this size was documented in 1950, with past documentation indicating the last bloom prior to that was in the turn of the 20th century.

The remarkable abundance of octopuses meant they could be frequently seen in shallow waters for the first time in recent history. Diver videos show octopuses congregating together – contrary to their normally lone nature – and “walking” along the seabed on their arm ends. A curious octopus was even seen investigating an underwater camera.

“The first time I dived off the Lizard peninsula this year I saw multiple octopuses,” the specialist continued. “And these are big. Two kinds exist in these waters. The curled octopus is quite small, football-sized, but these common octopuses can be reaching impressive sizes.”

Future Prospects and Other Surprises

If conditions remain mild going into 2026 could lead to a repeat event in 2026, because in the past, in similar situations, populations have surged again for two years running.

“However, it is unlikely, from previous blooms, that it will persist indefinitely,” they cautioned. “Marine life is unpredictable these days so it’s hard to forecast.”

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

• Highest-ever counts of gray seals observed in Cumbria.
• Record numbers of puffins on Skomer.
• A first-ever sighting of an unusual mollusc in Yorkshire, typically a southwestern species.
• A variable blenny found off the coast of a southern county for the first time.

Not All Positive News

Not everything was good news, however. “The period was framed by environmental disasters,” said a head of marine conservation. “A major tanker collision in March and a spill of plastic pollution off the Sussex coast served as stark reminders. Staff and volunteers are working tirelessly to safeguard and rehabilitate our coasts.”