2025 Proclaimed 'The Octopus Year' Off England's South Coast.
Unprecedented observations of one of the world's most intelligent invertebrates this past summer have prompted the declaration of 2025 as the octopus's year in a yearly report of Britain’s seas.
A Perfect Storm for a Population Boom
A mild winter followed by a remarkably hot spring triggered a huge population of Mediterranean octopuses to settle along the southern coastline of England, spanning the Cornish and Devonian coasts.
“The scale of the catch was approximately 13 times what we would normally expect in Cornish waters,” commented an ocean conservation expert. “Based on the totals, around 233 thousand octopuses were caught in these waters this year – that’s a huge increase from the norm.”
The common octopus is native to British seas but usually so scarce it is infrequently encountered. A population bloom is attributed to a combination of a mild winter and a warm breeding season. Such favorable circumstances meant a higher survival rate for young, maybe aided by significant populations of other marine life seen in the area.
A Rare Phenomenon
The most recent occasion, an octopus bloom of this size was documented in the 1950s, with archival data indicating the one before that was in 1900.
The huge numbers of octopuses meant they could be readily observed in shallow waters for a rare occurrence. Diver videos show octopuses congregating together – unlike their typical solitary behavior – and ambulating along the bottom on the tips of their limbs. One creature was even seen investigating an underwater camera.
“On my initial dive off the Lizard peninsula this year I saw five octopuses,” the specialist continued. “And these are big. There are two types in the region. One species is rather small, the size of a ball, but the *Octopus vulgaris* can be reaching impressive sizes.”
Looking Ahead & Coastal Highlights
A second gentle winter going into 2026 meant it was possible a repeat event in 2026, because based on records, with such patterns, the blooms have repeated for two consecutive years.
“But, it's improbable, looking at history, that it will go on for a long time,” they cautioned. “But the sea keeps giving us surprises currently so it’s quite an unpredictable situation.”
The assessment also noted additional positive marine news along the coast, including:
- A record number of gray seals seen in one northern region.
- Peak numbers of the iconic seabirds on Skomer.
- The initial discovery of a rare sea slug in a northern county, usually found in the south-west.
- A Mediterranean fish species spotted off the coast of Sussex for the first occasion.
Environmental Concerns
Challenges were also present, however. “The year was bookended by ecological challenges,” noted a conservation leader. “A significant shipping incident in March and an accidental discharge of plastic pollution off the southern coast highlighted ongoing threats. Conservation teams are putting in immense work to defend and heal our shorelines.”