Huge numbers of jellyfish have been reported in a West Highland sea loch amid increasing evidence of a worldwide increase in the gelatinous marine animals.
Experts say it is unclear whether the sudden surge is the result of low mackerel catches or if other factors have caused the phenomenon.
Noel Hawkins, who works on the Summer Queen Cruises out of Ullapool, has been monitoring and photographing changes to the marine environment.
He said: "Huge numbers of jellyfish have been shoaling at Ullapool Harbour and Loch Broom. Numbers not seen in years have been accumulating around the sea, coast and washing ashore on the beaches."
He said there was concern that the jellyfish may be having an impact on fish numbers in the area, with little sign of the expected annual mackerel shoals.
Mr Hawkins explained: "Certain fishing zones in the world have reported 'jellification', where jellyfish have reached such levels that other species have been displaced. There are scientific teams looking into this, but we just don't know.
"The most common species are the harmless blue-ringed moon jellyfish but there are also blue jellyfish and red lion's mane that can cause swimmers and fishermen problems if touched. There are also continued reports of barrel jellyfish, the largest jellyfish encountered in UK waters."
Faserburgh-based Andrew Tait, of the Scottish Pelagic Fishermen's Association, has spent 50 years fishing.
He said: "I am on the board of the west coast inshore group and they are making a big effort to catch more mackerel because of the increased allocation, but the uptake has been poor this year. I wouldn't think the jellyfish would have anything to do with it."
He said fishermen had noticed climate change was having an effect on water and tidal streams. "Our concern is that it doesn't affect the spawning cycle of the fish. Water to the fish is like air to us. If they don't like the water they could spawn in a place different to the last 100 years."
Calum Duncan, Scotland Programme Manager at the Marine Conservation Society, said: "It is very difficult to link cause and effect with certainty. That is why we are very keen that the public report their sightings of jellyfish to us so we can get a fuller picture. It appears that proliferations of jellyfish blooms across the world are on the rise.
"Jellyfish are just large plankton, so you get naturally occuring blooms caused by the surface of the sea getting warmer in spring and summer which, combined with current and wind, can lead to localised aggregation.
"That may be the explanation of what has happened in Loch Broom."
But he said climate change and pollution from agricultural run-off are taking nutrients into the sea which artificially boost the blooms.
Mr Duncan said: "However, globally there is also speculation that over-fishing may be contributing to the blooms. Fish eat plankton. If you have fewer fish to eat the plankton, then there may well be bigger blooms.
"So it could also be that there are more jellyfish in Loch Broom because there are fewer mackerel, rather than the other way round."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article