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

Unprecedented sightings of one of the world's most intelligent invertebrates over the summer months have prompted the designation of 2025 as the year for octopuses in a yearly report of UK coastal waters.

A Confluence of Factors Leading to an Explosion

An unusually warm winter followed by an exceptionally warm spring triggered unprecedented numbers of Mediterranean octopuses to take up residence along the southern coastline of England, across the southwestern peninsula.

“The reported landings was of the order of about thirteen times what we would usually anticipate in the waters around Cornwall,” explained an ocean conservation expert. “Based on the totals, around 233 thousand octopuses were present in these waters this year – which is a significant rise from what is typical.”

The common octopus is native to these waters but ordinarily in such small numbers it is rarely seen. A sudden increase 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, possibly in part fuelled by significant populations of spider crabs seen in the area.

A Rare Phenomenon

The last time, an octopus bloom this significant was recorded in the mid-20th century, with past documentation indicating the previous major event was in 1900.

The huge numbers of octopuses meant they could be frequently seen in shallow waters for the first time in recent history. Underwater recordings show octopuses congregating together – contrary to their normally lone nature – and “walking” along the bottom on their tentacle tips. One creature was even recorded reaching for an underwater camera.

“During a first dive there this year I saw five octopuses,” the specialist continued. “And these are big. Two kinds exist in UK waters. The curled octopus is quite small, about the size of a football, but these newcomers can be up to a metre and a half wide.”

Predictions and Marine Joy

If conditions remain mild this coming winter could lead to another surge in 2026, because in the past, in similar situations, populations have surged again for two years in a row.

“Still, the chances are low, from previous blooms, that it will persist indefinitely,” they cautioned. “The ocean is full of surprises currently so it’s a very uncertain scenario.”

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

• Highest-ever counts of gray seals observed in one northern region.
• Exceptional populations of puffins on Skomer.
• A first-ever sighting of a rare sea slug in a northern county, typically a southwestern species.
• A Mediterranean fish species spotted off the coast of Sussex for the first time.

A Note of Caution

Challenges were also present, however. “The period was framed by marine incidents,” stated an expert. “A significant shipping incident in March and an accidental discharge of tonnes of plastic biobeads off the Sussex coast were serious issues. Dedicated individuals are making huge efforts to protect and restore our shorelines.”