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

Record-breaking observations of one of the world's most intelligent invertebrates over the summer months have resulted in the designation of 2025 as the octopus's year in an annual review of UK coastal waters.

Ideal Conditions for a Population Boom

A gentle winter followed by an exceptionally warm spring catalyzed a huge population of common octopuses (*Octopus vulgaris*) to establish themselves along England’s south coast, spanning the Cornish and Devonian coasts.

“The scale of the catch was of the order of about thirteen times what we would usually anticipate in this region,” stated an ocean conservation expert. “Calculating the figures, around 233 thousand octopuses were found in UK waters this year – that’s a huge increase from historical averages.”

The common octopus is indigenous to these waters but usually so scarce it is infrequently encountered. A population bloom is attributed to the dual effect of a mild winter and a warm breeding season. Such favorable circumstances meant a higher survival rate for young, potentially supported by abundant stocks of spider crabs also recorded.

A Historic Event

The last time, an octopus bloom of this size was observed in the 1950s, with past documentation indicating the previous major event happened in the turn of the 20th century.

The sheer quantity of octopuses meant they could be readily observed in coastal areas for a rare occurrence. Video footage show octopuses congregating together – contrary to their normally lone nature – and “walking” along the ocean floor on the tips of their limbs. One individual was even recorded reaching for a diver's camera.

“On my initial dive in that area this year I saw five of these creatures,” they noted. “They are large specimens. We have two species in the region. One species is quite small, the size of a ball, but these newcomers can be up to a metre and a half wide.”

Looking Ahead & Coastal Highlights

A second gentle winter going into 2026 suggests the potential a second bloom the following year, because in the past, with such patterns, 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. “Marine life is unpredictable currently so it’s a very uncertain scenario.”

The report also celebrated other “surprises, successes and joyful moments” across British shores, including:

• Unprecedented numbers of gray seals observed in one northern region.
• Exceptional populations of puffins on an island off Wales.
• The first recording of a rare sea slug in Yorkshire, usually found in the south-west.
• A variable blenny spotted off the coast of a southern county for the inaugural time.

A Note of Caution

Not everything was good news, however. “The period was framed by environmental disasters,” stated an expert. “A significant shipping incident in the North Sea and the release of industrial pellets off the southern coast highlighted ongoing threats. Dedicated individuals are making huge efforts to safeguard and rehabilitate our coasts.”