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

Exceptionally high observations of one of the world's most intelligent invertebrates over the summer months have led to the declaration of 2025 as the year for octopuses in an annual review of the nation's marine environment.

A Confluence of Factors Leading to an Explosion

A mild winter coupled with a remarkably hot spring catalyzed a huge population 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 13 times what we would normally expect in Cornish waters,” stated a marine conservation officer. “When we added up the numbers, nearly a quarter of a million octopuses were present in these waters this year – which is a significant rise from historical averages.”

*Octopus vulgaris* is native to British seas but usually so scarce it is rarely seen. An explosive growth is attributed to the dual effect of gentle winter conditions and a warm breeding season. These ideal conditions meant increased juvenile survival, potentially supported by large numbers of other marine life noted in recent years.

A Historic Event

The most recent occasion, a population surge of this scale this significant was documented in the mid-20th century, with historical records indicating the previous major event happened in 1900.

The remarkable abundance of octopuses meant they could be easily spotted in nearshore environments for a rare occurrence. Underwater recordings show octopuses congregating together – contrary to their normally lone nature – and moving along the bottom on their arm ends. A curious octopus was even recorded reaching for a diver's camera.

“During a first dive in that area this year I saw multiple octopuses,” they noted. “And these are big. There are two types in the region. One species is rather small, football-sized, but these common octopuses can be up to a metre and a half wide.”

Predictions and Marine Joy

If conditions remain mild this coming winter suggests the potential a second bloom the following year, because based on records, with such patterns, populations have surged again for two years running.

“Still, the chances are low, based on past events, that it will persist indefinitely,” they said. “But the sea keeps giving us surprises currently so it’s quite an unpredictable situation.”

The annual review also noted other “surprises, successes and joyful moments” along the coast, including:

• A record number of grey seals recorded in one northern region.
• Record numbers of the iconic seabirds on Skomer.
• A first-ever sighting of an unusual mollusc in Yorkshire, normally residing farther south.
• A Mediterranean fish species found off the coast of a southern county for the first time.

A Note of Caution

The year had its low points, however. “The year was bookended by environmental disasters,” stated an expert. “A major tanker collision in March and an accidental discharge of tonnes of plastic biobeads off the southern coast were serious issues. Staff and volunteers are putting in immense work to protect and restore our shorelines.”