But on Monday, there was talk that the traditional meal of fish and chips could be replaced with a version of squid and chips after new research showed that cold-water fish, such as cod and haddock, are leaving Britain’s warming waters and heading north. They are being replaced with squid, anchovies and red mullet — species that thrive in warmer waters.

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The research on changing fish populations in the North Sea, presented Monday at the British Ecological Society’s annual conference, comes from the Center for Environment, Fisheries and Aquaculture Science (Cefas), a British government research agency.

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“Our models for 2025 and beyond suggest that seawater temperature may continue to rise in the future. As a result, U.K. waters will become more hospitable for some species and less suitable for others, with the overall result that most commercial species will move northward,” said John Pinnegar, the program director for marine climate change at Cefas.

Cefas, which has been studying North Sea fish populations for more than 100 years, said that the number of squids in the region has risen sharply over the past three decades. In 1984, the lab found squids at 20 percent of its 76 survey stations in the North Sea — in 2014, that figure was 60 percent.

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Cod, a particular favorite here, has been struggling to make a comeback after decades of overfishing. With cod numbers severely depleted, Britain become reliant on importing the fish from places such as Iceland and Norway. Cod numbers in the North Sea fell to their lowest level in 2004 and have risen slowly since then, even with various fishing restrictions. Scientists say the Britain's warming waters are affecting fish reproduction.

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Pinnegar said that Brits may need to become more excited about fish other than their traditional favorites.

“U.K. consumers enjoy eating quite a limited range of seafood, but in the long term, we will need to adapt our diets,” he said. “In 2025 and beyond, we may need to replace cod and other old favorites with warm-water species, such as squid, mackerel, sardine and red mullet.”

There was mixed reaction on social media to the proposed reworking of the national dish. There were some, like calamari lovers, who found reason for cheer. But there were others, too, for whom it seemed as if anything less than traditional fish and chips could be a tough sell.