2025 Declared 'The Octopus Year' Off Britain's South Coast.

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

A Perfect Storm Leading to an Explosion

A gentle winter coupled with a remarkably hot spring triggered a massive influx of common octopuses (*Octopus vulgaris*) to establish themselves along England’s south coast, across the southwestern peninsula.

“The scale of the catch was roughly over a dozen times what we would normally expect in the waters around Cornwall,” explained an ocean conservation expert. “Based on the totals, around 233 thousand octopuses were caught in British seas this year – that’s a huge increase from historical averages.”

The Mediterranean octopus is found in UK waters but typically so rare it is infrequently encountered. A population bloom is the result of the dual effect of gentle winter conditions and a warm breeding season. This perfect scenario meant increased juvenile survival, possibly in part fuelled by large numbers of other marine life noted in recent years.

A Rare Phenomenon

The most recent occasion, a population surge of this scale of this size was observed in the 1950s, with past documentation indicating the one before that happened in 1900.

The sheer quantity of octopuses meant they could be easily spotted in coastal areas for a rare occurrence. Underwater recordings show octopuses gathering in groups – contrary to their normally lone nature – and ambulating along the seabed on their arm ends. A curious octopus was even seen investigating an underwater camera.

“During a first dive in that area this year I saw multiple octopuses,” the specialist continued. “They are sizeable. Two kinds exist in the region. The curled octopus is quite small, the size of a ball, but these common octopuses can be up to a metre and a half wide.”

Predictions and Marine Joy

If conditions remain mild heading into next year could lead to a second bloom the following year, because based on records, in similar situations, events have occurred consecutively for two consecutive years.

“However, it is unlikely, based on past events, that it will go on for a long time,” they said. “The ocean is full of surprises currently so it’s quite an unpredictable situation.”

The annual review also noted additional positive marine news along the coast, including:

• A record number of gray seals recorded in Cumbria.
• Exceptional populations of puffins on a Welsh island.
• A first-ever sighting of an unusual mollusc in a northern county, normally residing farther south.
• A type of blenny discovered off the coast of a southern county for the first time.

Not All Positive News

Not everything was good news, however. “The year was bookended by marine incidents,” said a head of marine conservation. “A major tanker collision in the North Sea and a spill of tonnes of plastic biobeads off the Sussex coast were serious issues. Conservation teams are putting in immense work to protect and restore our coasts.”