2025 Proclaimed 'The Octopus Year' Off England's Southern Shores.

Record-breaking observations of one of the world's most intelligent invertebrates this past summer have resulted in the naming of 2025 as the year for octopuses in a seasonal assessment of UK coastal waters.

A Perfect Storm for a Population Boom

A gentle winter coupled with an exceptionally warm spring triggered a massive influx of Mediterranean octopuses to take up residence along the shores from Cornwall to Devon, spanning the Cornish and Devonian coasts.

“The reported landings was roughly over a dozen times what we would normally expect in Cornish waters,” stated a marine life specialist. “When we added up the numbers, around 233 thousand octopuses were found in these waters this year – that’s a huge increase from what is typical.”

The Mediterranean octopus is found in these waters but ordinarily in such small numbers it is rarely seen. A population bloom is the result of the dual effect of gentle winter conditions and favorable spring temperatures. These ideal conditions meant increased juvenile survival, possibly in part fuelled by large numbers of a favored prey species noted in recent years.

A Rare Phenomenon

The last time, a population surge of this scale of this size was observed in 1950, with past documentation indicating the previous major event occurred in the turn of the 20th century.

The huge numbers of octopuses meant they could be easily spotted in nearshore environments for the first time in living memory. Diver videos show octopuses being sociable – unlike their typical solitary behavior – and ambulating along the ocean floor on the tips of their limbs. One individual was even filmed grabbing an underwater camera.

“The first time I dived there this year I saw multiple octopuses,” the officer added. “They are large specimens. We have two species in these waters. The curled octopus is smaller, the size of a ball, but these common octopuses can be up to a metre and a half wide.”

Looking Ahead & Coastal Highlights

Another mild winter this coming winter meant it was possible another surge the following year, because based on records, in similar situations, the blooms have repeated for two years running.

“However, it is unlikely, based on past events, that it will become a permanent fixture,” they said. “But the sea keeps giving us surprises currently so it’s a very uncertain scenario.”

The report also highlighted additional positive marine news across British shores, including:

• Unprecedented numbers of gray seals recorded in one northern region.
• Exceptional populations of puffins on a Welsh island.
• The initial discovery of a rare sea slug in a northern county, typically a southwestern species.
• A Mediterranean fish species found off the coast of a southern county for the inaugural time.

Not All Positive News

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 March and a spill of tonnes of plastic biobeads off the southern coast were serious issues. Staff and volunteers are working tirelessly to defend and heal our coasts.”