Government scientists say squid, which thrives in warmer waters, is flourishing around the North Sea.
They say haddock and cod, a staple of a Scottish chippy order, are heading north, away from British seas.
Dr John Pinnegar, of the Centre for Environment, Fisheries and Aquaculture Science (Cefas), which has been monitoring North Sea fish populations for more than 100 years, said models for 2025 and beyond suggested that seawater temperatures off the UK may continue to rise.
“Twenty or 30 years ago we hardly saw squid in our surveys,” said Dr Pinnegar.
“A lot of the things we see increasing in abundance around the UK are fish that would probably originally [be] thought of as being Mediterranean or characteristic of the Bay of Biscay, or around Portugal or Spain,” he added.
“They’re now increasing in UK waters because the waters are getting more conducive for those sorts of species, whereas other species are shifting the centre of their distribution towards the north of the UK.”
Data shows the distribution of cod has moved north towards Norway.
“Maybe consumers might like to choose species that are distributed in our own waters,” he said.
“There are quite a lot of species that seem to be increasing - things like red mullet, anchovies, sardines, John Dory, squid - all of these are quite nice to eat but they are the kind of thing you would have normally have eaten on your holiday to Spain or Portugal.”
A study earlier this year found that squid appeared to be benefiting from climate change, at the expense of finned fish, and they have been identified as a valuable alternative fishing target, particularly in the North Sea.