Elijah Voge-Meyers carries cod caught in the nets of a trawler off the coast of New Hampshire on April 23, 2016. (AP Photo/Robert F. Bukaty, file)

(CN) – Using DNA barcodes to certify where sustainable fish come from significantly cuts back on mislabeled fish, a new study suggests.

As global consumption of fish and seafood increases, so have pleas from sustainability advocates to raise and sell fish in more responsible ways.

Fish that is mislabeled, deliberately or otherwise, remains a challenge. A recent study of 4,500 seafood product tests concluded that an average of 30 percent of seafood is mislabeled in restaurants and by retailers.

In some cases, the mislabeling is unintentional – sometimes the result of mix-ups during processing or species being misidentified when caught. Other cases involve fraud, like passing off farmed catfish as cod.

A new study published Monday in Current Biology looked at the practices of the Marine Stewardship Council, an organization that labels sustainably harvested fish from a traceable supply chain.

The council’s certification process requires every entity trading its certified seafood to document how it is keeping the certified fish from the non-certified.

Researchers used DNA barcode technology to look at 1,402 fish products certified by the council. They found just 13 incorrectly labeled. All but one of the mislabeled products were found in western Europe and all involved either whitefish or flatfish products.

The results suggest to the researchers that the council’s supply chain certification process is an effective way to ensure that sustainably-sourced fish is labeled as such.

“The use of DNA tools to detect substitution in the fish supply chain is well-documented but until now has essentially revealed a depressing story,” said Rob Ogden from the University of Edinburgh.

“Our research flips this on its head and demonstrates how we can apply similar technology to validate the success of eco-labels in traceable, sustainable fishing.”

The Marine Stewardship Council’s study was done in conjunction with the laboratories at the TRACE Wildlife Forensics Network, as well as Science and Advice for Scottish Agriculture.

This month, the conservation group Oceana reported widespread mislabeling of seafood in the United States after conducting an investigation of more than 400 samples from across the country.

The group found 21 percent of the samples, which included sea bass and snapper, were mislabeled. About a third of the establishments they visited sold seafood that was mislabeled, according to the investigation.