2025 Proclaimed 'The Octopus Year' Along Britain's South Coast.

Exceptionally high encounters of one of the world's most intelligent invertebrates during the summer season have prompted the designation of 2025 as “the year of the octopus” in an annual review of UK coastal waters.

A Confluence of Factors Leading to an Explosion

A mild winter followed by an exceptionally warm spring triggered unprecedented numbers 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 thirteen times what we would usually anticipate in the waters around Cornwall,” stated a marine life specialist. “When we added up the numbers, nearly a quarter of a million octopuses were found in British seas this year – that’s a huge increase from historical averages.”

*Octopus vulgaris* is found in UK waters but usually so scarce it is seldom observed. A sudden increase is attributed to a combination of a mild winter and favorable spring temperatures. These ideal conditions meant more larvae, maybe aided by abundant stocks of spider crabs seen in the area.

A Rare Phenomenon

The most recent occasion, an octopus bloom comparable was documented in the mid-20th century, with historical records indicating the last bloom prior to that occurred in 1900.

The remarkable abundance of octopuses meant they could be frequently seen in nearshore environments for the first time in living memory. Underwater recordings show octopuses being sociable – unlike their typical solitary behavior – and “walking” along the seabed on the tips of their limbs. A curious octopus was even recorded reaching for submarine recording equipment.

“The first time I dived in that area this year I saw multiple octopuses,” they noted. “They are sizeable. We have two species in the region. One species is rather small, the size of a ball, but the *Octopus vulgaris* can be with a span of 1.5 meters.”

Looking Ahead & Coastal Highlights

Another mild winter this coming winter could lead to a repeat event the following year, because historically, in similar situations, the blooms have repeated for two years in a row.

“However, it is unlikely, looking at history, that it will persist indefinitely,” they said. “But the sea keeps giving us surprises currently so it’s hard to forecast.”

The annual review also highlighted further encouraging coastal sightings across British shores, including:

• A record number of grey seals recorded in Cumbria.
• Exceptional populations of puffins on an island off Wales.
• The initial discovery of the *Capellinia fustifera* nudibranch in a northern county, normally residing farther south.
• A Mediterranean fish species spotted off the coast of Sussex for the first time.

A Note of Caution

The year had its low points, however. “The period was framed by environmental disasters,” said a head of marine conservation. “A significant shipping incident in March and the release of plastic pollution off the Sussex coast highlighted ongoing threats. Conservation teams are working tirelessly to safeguard and rehabilitate our coasts.”