Summit County Citizens Voice

Some certified ‘Chilean sea bass’ sold in stores doesn’t qualify for the label

A Patagonian toothfish, sometimes sold in stores as Chilean sea bass. Photo by Monterey Bay Aquarium Seafood Watch.

By Summit Voice

SUMMIT COUNTY — It turns out you can’t trust anyone these days, especially not the fishmonger at your local market. A recent DNA study by Clemson University biologists shows that some eco-certified Chilean sea bass sold in grocery stores does not qualify for the label — in some cases, it’s not even sea bass at all.

“Our data point to a problem with the supply chain,” said Clemson population biologist Peter Marko. “Fish are being sold that are improperly labeled. Where and how the uncertified fish reach market was not the focus of our research but are issues that deserve attention.”

The fish is slow-growing and reproduces late in life, factors that make it susceptible to over-fishing, according to the Monterey Bay Aquarium’s Seafood Watch program.

More info from the seafood watch program:

“The fishing methods used to catch Chilean seabass cause more problems: bottom trawling can damage seafloor habitat, and miles of baited longline gear can fatally hook and drown endangered albatross and other seabirds. For these reasons, most Chilean seabass should be avoided.”

In the case of Chilean sea bass, certification labels from the Marine Stewardship Council should indicate that a fish was harvested from the only recognized sustainable Chilean sea bass fishery, a population living in waters surrounding the sub-Antarctic island of South Georgia and a nearby plateau called Shag Rocks, Marko explained.

Restaurants and retailers selling the fish should be able to produce chain of custody certification. If they can’t, consumers should assume the fish was harvested illegally.

And Marko’s research shows that, even if the documentation does exist, it’s not always valid — a good reason for consumers to avoid the fish altogether. The seafood watch program suggests Sablefish (black cod) from Alaska and British Columbia, and Pacific halibut as the best alternative choices for consumers.

Marko and his fellow researchers, Holly Nance and Kimberly Guynn, bought fish in grocery stores and then did some DNA analysis to compare with fish known to have come from the certified fishery. Some of the fish that his team purchased turned out to be other species entirely.  Altogether, they analyzed mitochondrial DNA from fish purchased at retail outlets in eight states. Eight percent of 36 fish sampled were “actually other species,” according to Marko.

Of those that were Chilean sea bass, some 15 percent were genetically distinct from fish collected previously from the certified fishery. One sample likely originated on the other side of the globe, in the southern Indian Ocean. Other genetic markers that the researchers uncovered amongst fish marked with an MSC-certified label commonly trace to South American waters, and still others had never been recorded before in previous genetic surveys.

The scientists reported their findings in the Aug. 23 issue of Current Biology, a Cell Press publication.

“The simplest explanation for this result is that other species plus Chilean sea bass from other, uncertified fisheries are being added to the supply chain for MSC-certified Chilean sea bass,” Marko said. The results were unexpected but not exactly shocking, according to Marko, given widespread mislabeling in the seafood industry and the potential profits to be made.

It isn’t clear who is responsible for the misleading labels, given that fish pass through many hands from the time they are caught to the time they are purchased.

“There is no question that organizations like the Marine Stewardship Council are trying their best to guide consumers to sustainably harvested seafood, but it is currently difficult to guarantee the geographic origins of fish,” Marko said. He added that the MSC has been working on ways to confirm fishes’ origins, and the new study may serve as a model for how to go about that.

The only thing it seems that concerned consumers can really do for now is keep Chilean sea bass off their dinner menus. “At a grocery or on a plate in a restaurant, Chilean sea bass from South Georgia looks the same as Chilean sea bass from other parts of the world,” Marko said.

Marko has been a fish sleuth before. In 2004, he and his students at the University of North Carolina at Chapel Hill used genetic analyses to identify red snapper, finding out that a significant number of the fish sold in markets were not what were advertised.

Filed under: biodiversity, endangered species, Environment, Summit County news Tagged: | biodiversity, Chilean sea bass, Clemson University, endangered species, Environment, Marine Stewardship Council, Patagonian toothfish, Seafood Watch, sustainable seafood