In the wake of high profile reports of seafood mislabeling, the FDA recently announced it will expand its use of DNA testing in inspections of seafood manufacturers and restaurants. Proponents say this testing, known as DNA barcoding, will enhance detection of fish caught illegally or illegally substituted for other species, but some warn that such testing could be ineffective if enforcement agents don’t receive proper training.

DNA barcoding involves rapid testing of a small sample to see if its genetic makeup matches with genetic markers of a species.

A group of international researchers have launched the Barcode for Life initiative to expand DNA barcoding for field research and food inspection. The FDA is already using this method for some inspections and is working with researchers to create testing protocols and DNA reference libraries to expand its use. The agency has outfitted nine new field laboratories for DNA barcoding according to FDA spokesman Douglas Karas.

Conservationists hope DNA barcoding will help curb rampant mislabeling of seafood. Approximately 1/3 of seafood sold in the U.S. is mislabeled, estimates Margot Stiles, a marine scientist with Oceana, a marine-conservation organization. Often, an off-limits species or fish caught outside of catch-limit rules enter the U.S. market through deception, said Stiles.

“It’s hidden underneath some other piece of fish or is mislabeled,” said Stiles.

Recently, a Boston Globe investigation found that nearly half of the seafood sampled from Boston-area restaurants was mislabeled. Often, cheaper seafood was substituted for more expensive species on menus. Restaurant owners interviewed for the investigation said they thought the practice was widespread; some even claimed the bait-and-switch tactics were sanctioned by the FDA, which it is not.

In an email, Karas said that the FDA was not pressured to expand DNA barcoding in response to the expose. The agency has been working carefully to create DNA barcoding standards that will be strong enough to stand up in court.

“This has been in the works for a while,” Karas wrote in an email.

The agency is doing limited field-testing of DNA barcoding for enforcement. In 2010, for example, DNA barcoding was used by the FDA to detect that an Illinois seafood manufacturer, Gourmet Express Marketing Inc., had substituted ocean perch for seafood labeled as red snapper. The FDA opened up an enforcement case against the company partly because of the testing.

But the FDA doesn’t necessarily need to use DNA barcoding solely for court-admissible evidence, said David Schneider, Executive Secretary of the Consortium for the Barcode of Life.

“Barcoding is fast and cheap and could be used as a ‘triage’ tool to identify producers and distributors who merit closer investigation,” Schneider wrote in an email.

While headlines have focused on the discovery of seafood substitution in restaurants, some biologists see the most potential for DNA barcoding in detecting mislabeled seafood imports. It’s estimated that just two percent of imported seafood is currently inspected, and often inspectors aren’t qualified to detect illegal imports, said Richard Mayden, chairman of the biology department at Saint Louis University.

“Most of the people working the border, they don’t know what they’re looking at,” said Mayden. “They don’t know the scientific name; they don’t know the common name.”

Conservationists like Stiles hope expanded DNA barcoding will give inspectors a rapid and reliable way to test imports.

“There’s no control otherwise of fish coming into the country,” Stiles said.

But if done poorly, such testing can create new problems, said Mayden. While he favors expanded use of DNA barcoding, he warns that it won’t work unless wildlife and border officials are properly trained.

In the 90s, he said, one DNA testing laboratory held up caviar imports because of mistaken identification of samples. The error devastated some importers.

“They better have some people who know what the hell they are doing,” Mayden said.

But seafood stakeholders and conservationists agree that if the federal government increases its enforcement against seafood substitution, it will be following the lead of the marketplace.

“What’s going to drive this is going to be the customer and the money,” Mayden sad.