DNA barcodes for seafood by David Schindel

A new technology will help you ensure that the fish on your plate is what it’s supposed to be. It’s called a DNA barcodes for seafood. Using your cellphone, you’ll be able to scan a barcode on a restaurant menu. Where was it fished? What fisherman caught this? When it was caught? Was it tested? Does this fisherman have a good record of authentic labeling? EarthSky spoke with David Schindel of the Smithsonian Institution about DNA barcodes. Schindel heads the Consortium for the Barcode of Life, an international project that aims to make a digital library of all life by collecting snippets of DNA. This interview is part of a special EarthSky series, Feeding the Future, produced in partnership with Fast Company and sponsored by Dow.

What are DNA barcodes?

DNA barcodes are DNA sequence data records taken from the same portion of the genome of all organisms that are sampled. They’re linked to the specimen that gave the tissue that was sequenced.

These records go into GenBank – a U.S. National Institutes of Health gigantic gene sequence database. It’s partnered with a similar large database in the UK for Europe, the European Molecular Biological Lab and the DNA Databank of Japan. All three of these big databases hold DNA barcode records.

But basically, a DNA barcode is a sheet of data. You can fit the data on one page. The core of it is the name of the species and a sequence of about 650 letters that we think of as the signature of that species.

Tell us how these DNA barcodes are being used in the food industry and restaurants.

One area is seafood. I think we’re all aware of the tremendous pressure that’s being put on seafood stock. I should include freshwater stock, both fin fish and invertebrates such as clams, mussels, lobsters and crabs. As we fish more and more of these supplies down, there’s pressure to find substitutions.

That is, there’s pressure to substitute a high-value species with something cheaper or farm-raised – a look-a-like that will not be detected by usual means – and to sell it at a high price.

There’s another pressure, which is really very unfortunate, and that is to fish protected species, which are already endangered and should not be harvested under any circumstances Selling protected species with fraudulent labeling as a legal species is one way of generating income.

DNA barcoding is a very straightforward way of testing this.

Right now, most of the barcoding is being done in academic research institutions and in government labs. But here’s how it would work for consumers. Think about a supply chain of fish. First, fishermen bring fish on shore. Most of the time, the fish has its skin and head still on, and it’s sold as a whole fish. But increasingly, as the fishing industry becomes industrialized, the fish are processed on-boat and they come ashore as fillets. Once the skin and head is off the fish, it can be very difficult to identify the species.

Now think about what you could do with DNA barcoding. Then, when fish filets come ashore, an organization or an agency like the Food and Drug Administration might take samples on some random or focused basis. And in a few hours, you could have identification of everything that was sampled.

Some species are more prone to mislabeling than others. Red snapper, halibut, cod, lots of things in the rockfish family, yellow fin tuna – these are high-priced fish that are fairly commonly mislabeled, sometimes accidentally, sometimes on purpose. In fact, our studies show anywhere from 30 to 50 percent fraudulent labeling either in seafood markets or in restaurants. It’s a little bit higher in restaurants and in supermarkets. Processed foods, like fish sticks for example, are commonly not labeled correctly.

How is the Consortium for the Barcode of Life working with the food industry to put these DNA barcodes to use?

We have been working with the Food and Drug Administration (FDA) for years. They’ve been very methodical in developing what they’re calling a reference fish encyclopedia, their own database of very high quality, high confidence barcode records. Their primary focus is on public health. Their interest started when there was a case of fraudulent labeling of fish that turned out to be imported as monkfish, but it turned out to be puffer fish. So there were cases of hospitalization.

More and more, I think, the FDA is sampling for consumer fraud. And as the FDA has taken interest, and media reports of fraudulent labeling became more common, the food industry took notice. We’ve been approached by several groups, mostly fish distributors, who want to create a voluntary standard. They say, it’s well and good for FDA to take an interest, but they think that the seafood industry has to clean its own house.

So they’re putting together a consortium of restaurants and distributors. They’ve approached us in the Consortium for the Barcode of Life to develop an industry standard, a voluntary set of standards about how fish are periodically sampled at the dock and during the transmission through the supply chain down to the restaurant. The goal is to sample that chain of material until it gets to the restaurant to make sure the labeling hasn’t been switched. We’re still at the stage of designing what the standard would be, what level of sampling would be appropriate to provide confidence. But I think it’s a really interesting and laudable effort on the part of the industry.

Here’s an experience that I’m looking forward to when I go to a restaurant. Of course, I’d like to know more about what I’m eating, the wine I’m ordering. I’d like to learn a little bit more about where it all came from. The image that some people have in mind is being able to sit down to a restaurant meal and take out your smart phone and scan a barcode on the menu and find out more about the species, more about how the dish is prepared but also about the species. Where was it fished? What fisherman caught this? When it was caught? Was it tested? Does this fisherman have a good record of authentic labeling? And all of that could be on your smart phone while you enjoy a glass of wine and you wait for your meal to be served. I think that would be not just comforting to me as a consumer but it would enrich the dining experience.

So I guess DNA barcoding ultimately will affect us in grocery stores, too.

Yes. For example, in some supermarkets, you’ll see the green and blue and orange labeling about the sustainability of those fish stocks. It let you make a decision about where you want to eat on the food chain. Large fish or small fish? What about the politics and economics of that fish? What about its sustainability? If you’re a foodie, and you have confidence in the species that you’re being served, will it allow you – over time – to focus on taste differences between this snapper and that snapper species? That’s something you can’t do if fish are fraudulently labeled.

So to all the seafood aficionados out there, beware of what you’re buying – and look forward to DNA barcoding, coming soon. When we have barcode testing in the marketplace, you’ll have much more confidence that you’re really getting the fish you want to buy.

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