2025 Declared 'The Octopus Year' Off Britain's South Coast.
Exceptionally high observations of a supremely intelligent sea creature 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 Leading to an Explosion
A mild winter followed by a very warm springtime catalyzed a huge population of Mediterranean octopuses to establish themselves along England’s south coast, from Penzance in Cornwall to south Devon.
“The volume of octopuses caught was approximately thirteen times what we would normally expect in the waters around Cornwall,” explained a marine conservation officer. “When we added up the numbers, around 233 thousand octopuses were present in these waters this year – representing a massive jump from historical averages.”
The Mediterranean octopus is indigenous to British seas but usually so scarce it is seldom observed. An explosive growth is the result of a combination of gentle winter conditions and favorable spring temperatures. This perfect scenario meant a higher survival rate for young, possibly in part fuelled by abundant stocks of spider crabs also recorded.
An Uncommon Occurrence
Previously, a population surge of this scale this significant was recorded in the mid-20th century, with past documentation indicating the last bloom prior to that happened in 1900.
The remarkable abundance of octopuses meant they could be frequently seen in coastal areas for the first time in recent history. Video footage show octopuses gathering in groups – contrary to their normally lone nature – and ambulating along the seabed on the tips of their limbs. A curious octopus was even filmed grabbing a diver's camera.
“During a first dive in that area this year I saw five octopuses,” the officer added. “They are sizeable. There are two types in these waters. One species is smaller, the size of a ball, but these newcomers can be up to a metre and a half wide.”
Future Prospects and Other Surprises
A second gentle winter heading into next year meant it was possible a second bloom in 2026, because based on records, in similar situations, events have occurred consecutively for two years running.
“Still, the chances are low, from previous blooms, that it will persist indefinitely,” they said. “The ocean is full of surprises these days so it’s hard to forecast.”
The report also celebrated other “surprises, successes and joyful moments” around the UK coastline, including:
- A record number of gray seals observed in one northern region.
- Record numbers of puffins on an island off Wales.
- The first recording of the *Capellinia fustifera* nudibranch in Yorkshire, typically a southwestern species.
- A type of blenny spotted off the coast of Sussex for the first time.
Environmental Concerns
The year had its low points, however. “The year was bookended by marine incidents,” said a head of marine conservation. “A major tanker collision in the North Sea and an accidental discharge of plastic pollution off the southern coast served as stark reminders. Staff and volunteers are putting in immense work to protect and restore our marine habitats.”