DNA Tests Expose Catfish Sold as Cod and Haddock in UK Chip Shops

A BBC investigation of chip shops in Liverpool and Manchester identified ten takeaways that listed cod, haddock or simply "fish" on their menus. DNA testing at Liverpool John Moores University showed three of the ten samples were pangasius, a tropical freshwater catfish also known as river cobbler.

Wholesale pangasius costs about £3.40 per kilogram, compared with roughly £15 per kilogram for cod and haddock. The price gap allows unscrupulous shops to boost margins while charging customers the same price as traditional fish. One shop bought pangasius portions for £3.80, £4.20 and £5, while cod or haddock servings sold for £4‑£6.

A chip shop owner in Liverpool, who prompted the investigation, said the practice “puts people like me at a disadvantage.” He noted that honest businesses must compete with lower‑priced, mislabelled fish, eroding consumer trust. The National Federation of Fish Friers echoed the concern, urging clear species labeling to protect the industry’s reputation.

Professor Stefano Mariani, who led the DNA analysis, explained that the technique matches genetic sequences to identify species. He said the three pangasius detections “is quite a lot” for fish‑and‑chip outlets and that most diners cannot distinguish catfish from cod without training.

Legal obligations require traders to disclose the species when asked, but many menus simply list “fish” or “traditional fish.” The Chartered Trading Standards Institute acknowledges that while the issue is not widespread, “some unscrupulous businesses” still operate. Responsibility for enforcement falls to the Food Standards Agency, which may delegate investigations to local authorities.

Consumer reaction ranges from curiosity to disappointment. A customer whose wife is Thai welcomed the chance to try catfish but stressed the need for clear labeling. Another regular expressed that ordering cod or haddock carries an expectation of a marine species, not a farmed freshwater fish.

The findings mirror past food‑labelling scandals, such as the 2013 horse‑meat incident, highlighting that deception, not safety, drives regulatory attention. As DNA testing becomes more accessible, further mislabelling could be uncovered.

What to watch next: Authorities may increase spot checks on chip shops, and industry groups could push for mandatory species disclosure on menus.