2025 Proclaimed 'The Octopus Year' Off Britain's Southern Shores.
Exceptionally high observations of one of the world's most intelligent invertebrates this past summer have prompted the designation of 2025 as the year for octopuses in an annual review of UK coastal waters.
A Confluence of Factors Leading to an Explosion
A gentle winter and then a remarkably hot spring prompted a huge population of common octopuses (*Octopus vulgaris*) to establish themselves along England’s south coast, across the southwestern peninsula.
“The volume of octopuses caught was approximately over a dozen times what we would normally expect in the waters around Cornwall,” commented a marine conservation officer. “Calculating the figures, approximately 233,000 octopuses were found in these waters this year – which is a significant rise from what is typical.”
The Mediterranean octopus is found in UK waters but typically so rare it is seldom observed. A population bloom is the result of the dual effect of a mild winter and a warm breeding season. These ideal conditions meant more larvae, maybe aided by large numbers of other marine life noted in recent years.
An Uncommon Occurrence
The most recent occasion, an octopus bloom of this size was documented in the mid-20th century, with past documentation indicating the one before that happened in the turn of the 20th century.
The remarkable abundance of octopuses meant they could be easily spotted in nearshore environments for the first time in recent history. Video footage show octopuses gathering in groups – unlike their typical solitary behavior – and “walking” along the ocean floor on their arm ends. One creature was even filmed grabbing submarine recording equipment.
“The first time I dived there this year I saw multiple octopuses,” the specialist continued. “And these are big. Two kinds exist in the region. One species is quite small, football-sized, but these newcomers can be up to a metre and a half wide.”
Looking Ahead & Coastal Highlights
A second gentle winter going into 2026 meant it was possible another surge in 2026, because in the past, with such patterns, events have occurred consecutively for two consecutive years.
“But, it's improbable, from previous blooms, that it will persist indefinitely,” they stated. “Marine life is unpredictable at the moment so it’s quite an unpredictable situation.”
The assessment also celebrated other “surprises, successes and joyful moments” along the coast, including:
- A record number of grey seals seen in Cumbria.
- Peak numbers of the iconic seabirds on an island off Wales.
- A first-ever sighting of the *Capellinia fustifera* nudibranch in Yorkshire, typically a southwestern species.
- A Mediterranean fish species 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 the North Sea and a spill of plastic pollution off the southern coast highlighted ongoing threats. Conservation teams are putting in immense work to safeguard and rehabilitate our coasts.”