2025 Proclaimed the 'Year of the Octopus' Off Britain's South Coast.

Record-breaking encounters of one of the world's most intelligent invertebrates during the summer season have resulted in the declaration of 2025 as the octopus's year in an annual review of the nation's marine environment.

A Perfect Storm Driving a Surge

A mild winter and then an exceptionally warm spring triggered a huge population of common octopuses (*Octopus vulgaris*) to take up residence along England’s south coast, spanning the Cornish and Devonian coasts.

“The scale of the catch was of the order of about 13 times what we would usually anticipate in Cornish waters,” stated an ocean conservation expert. “When we added up the numbers, approximately 233,000 octopuses were found in these waters this year – which is a significant rise from the norm.”

The Mediterranean octopus is found in these waters but ordinarily in such small numbers it is seldom observed. An explosive growth is attributed to the dual effect of a mild winter and a warm breeding season. These ideal conditions meant increased juvenile survival, possibly in part fuelled by large numbers of other marine life seen in the area.

A Historic Event

Previously, a population surge of this scale this significant was recorded in the mid-20th century, with archival data indicating the previous major event was in 1900.

The remarkable abundance of octopuses meant they could be frequently seen in nearshore environments for the first time in recent history. Diver videos show octopuses congregating together – unlike their typical solitary behavior – and “walking” along the seabed on their tentacle tips. One creature was even filmed grabbing a diver's camera.

“On my initial dive there this year I saw five of these creatures,” they noted. “They are sizeable. There are two types in these waters. One species is quite small, the size of a ball, but the *Octopus vulgaris* can be with a span of 1.5 meters.”

Predictions and Marine Joy

If conditions remain mild going into 2026 could lead to a repeat event the following year, because historically, in similar situations, events have occurred consecutively for two years in a row.

“But, it's improbable, from previous blooms, that it will become a permanent fixture,” they cautioned. “But the sea keeps giving us surprises at the moment so it’s a very uncertain scenario.”

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

• A record number of grey seals seen in Cumbria.
• Exceptional populations of puffins on a Welsh island.
• The initial discovery of an unusual mollusc in Yorkshire, usually found in the south-west.
• A type of blenny spotted off the coast of Sussex for the first occasion.

A Note of Caution

Challenges were also present, however. “The year was bookended by environmental disasters,” said a head of marine conservation. “A significant shipping incident in March and a spill of plastic pollution off the southern coast were serious issues. Dedicated individuals are making huge efforts to defend and heal our shorelines.”