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

Unprecedented sightings of a supremely intelligent sea creature this past summer have resulted in the naming of 2025 as “the year of the octopus” in a yearly report of the nation's marine environment.

Ideal Conditions Driving a Surge

An unusually warm winter and then an exceptionally warm spring triggered a huge population of common octopuses (*Octopus vulgaris*) to settle along the shores from Cornwall to Devon, from Penzance in Cornwall to south Devon.

“The reported landings was approximately thirteen times what we would normally expect in the waters around Cornwall,” commented a marine conservation officer. “When we added up the numbers, nearly a quarter of a million octopuses were found in British seas this year – that’s a huge increase from the norm.”

The common octopus is indigenous to these waters but ordinarily in such small numbers it is infrequently encountered. An explosive growth is the result of a combination of gentle winter conditions and favorable spring temperatures. Such favorable circumstances meant a higher survival rate for young, maybe aided by abundant stocks of spider crabs noted in recent years.

A Historic Event

The last time, such an octopus proliferation of this size was observed in the 1950s, with archival data indicating the last bloom prior to that occurred in 1900.

The huge numbers of octopuses meant they could be readily observed in coastal areas for the first time in recent history. Diver videos show octopuses gathering in groups – unlike their typical solitary behavior – and moving along the ocean floor on their arm ends. A curious octopus was even filmed grabbing a diver's camera.

“During a first dive there this year I saw five octopuses,” they noted. “And these are big. We have two species in the region. One species is smaller, the size of a ball, but these newcomers can be reaching impressive sizes.”

Looking Ahead & Coastal Highlights

If conditions remain mild this coming winter suggests the potential a repeat event next year, because based on records, with such patterns, events have occurred consecutively for two years running.

“However, it is unlikely, based on past events, that it will go on for a long time,” they stated. “Marine life is unpredictable these days so it’s a very uncertain scenario.”

The report also highlighted additional positive marine news along the coast, including:

• Unprecedented numbers of gray seals observed in one northern region.
• Peak numbers of the iconic seabirds on a Welsh island.
• The initial discovery of the *Capellinia fustifera* nudibranch in Yorkshire, normally residing farther south.
• A type of blenny found off the coast of Sussex for the first time.

A Note of Caution

The year had its low points, however. “The calendar year was marked by marine incidents,” stated an expert. “A significant shipping incident in March and the release of plastic pollution off the Sussex coast highlighted ongoing threats. Dedicated individuals are making huge efforts to protect and restore our marine habitats.”