Huge numbers of common octopus have been seen along the coastline of Cornwall, UK, this month in what experts are describing as a ‘bumper year’ for sightings. Cornwall Wildlife Trust’s conservation officers believe this could be evidence of an octopus population boom – an event last recorded along England’s south coast more than 70 years ago.
Despite its name, the common octopus (Octopus vulgaris) is rarely seen in UK waters and has been recorded by the wildlife charity just twice a year on average. The species is known for its large eyes, soft bag-like body and tentacles which can reach up to one metre in length. Like other cephalopods, their populations fluctuate dramatically as scientists attempt to learn more about their behaviour and abundance.
Divers and snorkellers have reported an increase in sightings of common octopus in Cornwall, particularly around the Lizard peninsula, the most southerly point of the British mainland. Local fishers along Cornwall’s south coast have also witnessed large numbers of octopus in their lobster pots and cuttlefish traps, with one Mevagissey fisherman reportedly catching 150 octopuses in a single day, compared to his usual catch of one or two a year.
‘I got really excited when I started receiving messages from our Seasearch divers – not only because sightings of these striking animals are few and far between, but because they’d seen several of them on one dive,’ said Matt Slater, marine conservation officer at Cornwall Wildlife Trust. ‘They are such amazing, alien creatures – one of the most intelligent animals in our oceans – and to witness a population explosion in our local waters would be incredible.’
Massive population booms of octopus are uncommon, but not unheard of. The Marine Biological Association has reported on several major octopus ‘plagues’ along the south coast of England from Lands End to Sussex; first in 1899 and most recently in the summer of 1948.
‘We hope this is a sign that octopus populations are healthy in our Cornish waters, but sadly not all of our marine life is thriving,’ said Slater. ‘By taking action for wildlife and recording your marine sightings with us, we can build up a picture over time and confirm if occurrences like this are a one-off or if octopus populations are steadily on the rise.’
For more about the trust and its activities, visit To find out more about Cornwall Wildlife Trust’s marine conservation work visit www.cornwallwildlifetrust.org.uk