UKDIVING
Cuttlefish with dusting of sand
PHOTO: MARK WALTERS this had previously been very rare in UK waters, there had been a large number of reports in the summer of 2022 around the South West of England. My Eddystone comber sighting wasn’ t a one-off, as we found quite a few more specimens later on Fairyland Wall, this time getting photographic evidence.
Octopus and chips, anyone?
Back at home after the trip, I was intrigued about our octopus and comber sightings and about what they might mean for the changing fortunes of the UK’ s marine fauna. SCUBA Editor Simon Rogerson suggested I contacted Dr Keith Hiscock, who has been monitoring the seas around Plymouth for more than 30 years.
Keith kindly pointed me to the online Marine Biological Association yearly reports on South-West Marine Ecosystems www. plymsea. ac. uk / id / eprint / 10439 / A mine of information, these reports show that combers first appeared in any numbers in the area in 2022, and from then on have become increasingly common. Common octopuses were rare until the same year, when there was a huge increase in numbers, including a fisherman netting 150 individuals on one day in early June. Then in 2023 came the first reported sighting of breeding octopus from Porthkerris in Cornwall.
These increases in marine species from further south in the past few years coincide with an increasing number of marine heatwaves in South West waters, so it is easy to make the link. If these trends continue, which seems highly likely, then we should expect to see an increasing number of marine species with southern distributions appearing in UK waters.
As an additional example of this, in the 2022 report I came across a picture of a pretty orange coloured nudibranch, Gargamella rosi, and I realized that during our recent dive trip I had seen two of these at the Eddystone, not realizing this species is another of the Southern immigrants. The downside to this trend is that our UK species which favour colder waters – for example, cod – will likely be pushed north as our waters warm. Perhaps in the future we will be eating octopus and chips, rather than cod and chips. �
Common octopus Tompot blenny
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PHOTO: ROB BINNS PHOTO: DAVID PITTS