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The mislabelling of fish is now amajor international concern.Fish stocks around the world arebeing over-exploited – in the last50 years nearly one in four of theworld’s fisheries has collapsed– and there has also been a dramatic rise inso-called IUU (illegal, unreported and unregulated)fishing. Worth as much as €20 billion a year, it’san industry that is putting further pressure on thesustainability of our fisheries in part due tomislabelling.Led by Dr Stefano Mariani, a marine biologist fromthe School of Environment & Life Sciences, a teamis investigating how to optimise and standardisethe way in which seafood products are geneticallyidentified, and ultimately make it easier toprosecute mislabelling offenders. According toMariani, part of the problem stems from the factthat most fish are now processed at sea, wheremany of the features that set individual speciesapart are removed.As a result, fish is sold in such a processed statethat it’s hard to know exactly what type of fish itis. This can lead to product substitution, when lessvaluable, more common species are mislabelledas rarer and often more expensive fish. As well asbreaking quotas for certain species, and putting afurther strain on the sustainability of fish stocks,it’s a practice that also cheats the consumerand may also expose them to the risk of foodallergies. “But don’t blame the fisherman,” saysMariani. “It’s a complicated supply chain and it’sthe big processing plants, supermarket chainsand suppliers that will decide the fate of differentbatches and orders of fish.”A recent survey in Americashowed shocking levelsof mislabelling, with over50% of fish wronglymarked.Worldwide issueIt’s a problem that is rife all over the world.A recent survey in America showed shocking levelsof mislabelling, with over 50% of fish wronglymarked. And despite the strong regulationsintroduced by the EU, there’s evidence that tunaand swordfish caught in the Mediterranean, aswell as North Sea cod, are also being mislabelled.What Mariani believes is needed is a forensic testthat will enable investigators to check whetherfish have been caught illegally, or whether aproduct in a supermarket or restaurant has beenmislabelled. DNA testing is central to this, andoffers a quick, cost-effective and reliable method,which can distinguish between species andprovide the forensic evidence needed to take acase to court. However, at the moment, a varietyof different methods are being used.Dr Stefano Mariani of theSchool of Environment &Life SciencesFish mislabellingA team of researchers at the University ofSalford is working on a process to stop aninsidious practice that is contributing to themismanagement of fish stocks worldwide.“The ultimate aim of the research is to producea simple, standardised process that allows you totake a piece of fish, subject it to the extractionof the DNA, and then the sequencing of aparticular portion of the DNA that identifiesthe actual species that you are dealing with,”explains Mariani. “It’s a process that is verysimilar to that which has been used in the recenthorse meat scandal.”Mariani’s research is part of a European projectcalled LABELFISH, which includes partners inIreland, Portugal, Spain, France and Germany, andwill focus on eight of the most popular species- Atlantic cod, haddock, hake, monkfish, plaice,tuna, ling and sardine. The research will also testthe effectiveness of EU legislation.Mariani’s team, and those in the partnercountries, have been testing shop-boughtsamples of fish using a variety of different DNAtesting technologies.“Traditionally different countries and differentgovernments had different control labs that wereusing different techniques to achieve the sameresults, and there was a lot of inconsistency.This can be a problem with potential legal cases.“We are aiming to standardise this wholeprocess as much as possible and hopefully this willthen become a model used around the world.“We want to ensure that in terms of procedure,collecting, delivery and reproducibility of all theresults, regardless of what country or laboratoryyou’re in, it’s going to be 100% reliable.“Ultimately,” he adds, “I would love to seenational, compulsory and well-enforced genetictesting, and random spot checking of productsalong the production chain in every country.”Below: Dr Mariani performs ademonstration at the ManchesterScience Festival in October 2012May 2013 | 39