DV-14-03 Identifying hake species in Maine markets

Anna Bass
University of New England

Like other ground or bottom-dwelling fish such as cod, haddock, and flounder, hake is a popular food fish. The name “hake” describes a number of different species—red, white, and long-finned hake, which are more closely related to cod, and silver hake or whiting—yet markets and menus typically just use “hake” without identifying the species. Mislabeling of seafood products is a worldwide issue. Authenticating the species of fish sold on the market is important for consumer health and prevention of the fraudulent sale of fish of lesser value.

Maine Sea Grant program development funds supported development of the Rapid Gadoid Identification Assay (RaGIA) to differentiate between five species of hake and six additional Gulf of Maine gadoids. This assay used Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) to assess the validity and specificity of labelling for hake, pollock and haddock fillets in two southern Maine markets. The markets were partners in the research.

Assay accuracy (percentage of samples matching the predicted pattern) was 100% for all species with the exception of silver hake (Merluccius bilinearis); 94.7%), spotted hake (Urophycis regia; 92.3%), and Atlantic cod (Gadus morhua; 77.8%). Market hake were identified as 93.5% white hake (U. tenuis) and 6.5% red hake (U. chuss). All market pollock and haddock were correctly identified. All fillets tested were sold under acceptable market names; however, the distributor’s label provided an incorrect scientific name for 29 fish. The information was provided to the participating markets, who can now be confident in assuring their customers that they are buying the “right” fish.

Laura Whitefleet-Smith, who worked with Bass on this project, won the Best Graduate Student Poster award at the 2014 New England Estuarine Research Society meeting in Salem, MA, for “Species identification of hake in Maine markets.”

Sea Grant funds: $1,752