When you buy what looks to be a nice piece of certified sustainable fish at the supermarket, you'd like to think that's exactly what you're getting. Unfortunately, things aren't always what they seem, according to researchers who have analyzed DNA isolated from store-bought, eco-labeled Chilean sea bass and report their findings in the August 23 issue of Current Biology, a Cell Press publication.
"We found that, for fish purchased in US groceries, not all those labeled as MSC-certified Chilean sea bass are actually MSC-certified Chilean sea bass," said Peter Marko of Clemson University. MSC stands for the Marine Stewardship Council, an international organization dedicated to recognizing and rewarding sustainable fishing.
In the case of Chilean sea bass, MSC certification labels 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.
In fact, some of the fish that his team purchased turned out to be other species entirely. Of those that were Chilean sea bass, some 15 percent were genetically distinct from fish collected previously from the certified fishery. One sample carried a haplotype (defined as a combination of genetic variants in cellular components known as mitochondria) that has only been found on the other side of the globe, in the southern Indian Ocean. Other haplotypes 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 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. Although unexpected, "the results are not exactly shocki
|Contact: Lisa Lyons|