‘Octopus boom’ in British waters for the first time in 70 years: Divers and fishermen report bumper sightings along Cornish coastline
- Huge numbers of octopus have been seen along Cornwall’s coastline this month
- Common Octopus rarely seen in Cornish waters – usually recorded twice a year
- Conservationists believe this could be evidence of an octopus population boom
- The last recorded south coast boom was in 1948 – more than 70 years ago
Huge numbers of octopus have been seen along Cornwall’s coastline this month, in what experts are describing as a ‘bumper year’ for the species.
Divers and snorkellers have reported an increase in sightings of Common Octopus (Octopus vulgaris), particularly around Cornwall’s Lizard peninsula.
One Mevagissey fisherman reported catching 150 octopuses in a single day, compared to his usual catch of one or two a year.
Despite its name, this large species of octopus is rarely seen in UK waters and has been recorded in Cornwall just twice a year on average.
Conservationists now 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, ‘Common Octopus’, this large species of octopus is rarely seen in UK waters and has been recorded in Cornwall just twice a year on average.
Octopuses and humans share ‘jumping genes’
New research reveals that the human and octopus brain both share the same ‘jumping genes.’
Over 45% of the human genome is composed of sequences called transposons, which are these ‘jumping genes’ that can ‘move’ from one point in a genome to another by shuffling or duplicating.
The research by Stazione Zoologica Anton Dohrn of Naples shows that the same ‘jumping genes’ are active both in the human brain and in the brain of two species, Octopus vulgaris, the common octopus, and Octopus bimaculoides, the Californian octopus.
‘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.’
The Common Octopus is known for its large eyes, soft bag-like body and tentacles which can span up to one metre (over 3 feet).
Like other cephalopods, their populations fluctuate dramatically, and scientists are attempting to learn more about their behaviour and abundance.
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.
Cornwall Wildlife Trust explained that female octopus lay a huge number of eggs – between 100,000 and 500,000.
Once hatched, they drift off with ocean currents and have to fend for themselves.
Many perish but, if conditions are good, many can survive, and this is why there are sometimes big increases in populations.
‘We hope this is a sign that octopus populations are healthy in our Cornish waters,’ said Slater.
‘But sadly not all of our marine life is thriving,’ he added.
‘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.’
OCTOPUS DEFENCE MECHANISMS
One of the most effective ways octopuses avoid predation is by camouflaging with their environment.
They have special pigment cells allow them to control the colour of their skin, much like chameleons.
As well as colour change they can manipulate the texture of their skin in order to blend in with the terrain.
As well as camouflage they can escape predators by using a ‘jet propulsion’ method of escape, where they rapidly shoot out water to propel them through the water rapidly.
The jet of water from the siphon is often accompanied by a release of ink to confuse and evade potential enemies.
The suckers on the tentacles of the eight-legged beasts are extremely powerful and are used to drag prey towards a sharp beak.
As well as protection from other animals, it has been recently found that octopuses can detect the ultrasonic waves that preempt a volcanic eruption or earthquake, giving them enough time to escape.
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