2025 Proclaimed the 'Year of the Octopus' Along Britain's Southern Shores.

Record-breaking encounters of one of the world's most intelligent invertebrates during the summer season have prompted the naming of 2025 as the year for octopuses in an annual review of UK coastal waters.

A Confluence of Factors for a Population Boom

An unusually warm winter followed by an exceptionally warm spring triggered a huge population of common octopuses (*Octopus vulgaris*) to establish themselves along England’s south coast, from Penzance in Cornwall to south Devon.

“The scale of the catch was roughly 13 times what we would typically see in this region,” explained a marine life specialist. “Based on the totals, approximately 233,000 octopuses were present in UK waters this year – representing a massive jump from what is typical.”

*Octopus vulgaris* is native to UK waters but ordinarily in such small numbers it is seldom observed. A population bloom is caused by the dual effect of gentle winter conditions and favorable spring temperatures. These ideal conditions meant more larvae, maybe aided by significant populations of spider crabs seen in the area.

An Uncommon Occurrence

Previously, an octopus bloom of this size was observed in the 1950s, with archival data indicating the last bloom prior to that happened in 1900.

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

“During a first dive there this year I saw five of these creatures,” they noted. “They are sizeable. There are two types in UK waters. The curled octopus is quite small, football-sized, but the *Octopus vulgaris* can be with a span of 1.5 meters.”

Predictions and Marine Joy

A second gentle winter this coming winter meant it was possible a repeat event the following year, because based on records, under these conditions, the blooms have repeated for two consecutive years.

“Still, the chances are low, based on past events, that it will go on for a long time,” they said. “But the sea keeps giving us surprises at the moment so it’s a very uncertain scenario.”

The assessment also highlighted additional positive marine news across British shores, including:

• Highest-ever counts of grey seals seen in Cumbria.
• Record numbers of puffins on a Welsh island.
• The first recording of a rare sea slug in Yorkshire, typically a southwestern species.
• A type of blenny spotted off the coast of a southern county for the first time.

Not All Positive News

Not everything was good news, however. “The period was framed by ecological challenges,” said a head of marine conservation. “A major tanker collision in March and a spill of industrial pellets off the Sussex coast highlighted ongoing threats. Conservation teams are working tirelessly to protect and restore our marine habitats.”