If you ordered grouper ($12 per pound) at a restaurant, and the chef slipped you catfish ($2.50 per pound) instead, could you tell the difference? Most diners can’t, which is where Mahmood Shivji comes in. Shivji’s a DNA researcher, who’s developed a method of testing the DNA in seafood dishes. In the past two years, he’s analyzed more than 100 restaurant plates, and discovered more than half were misleading customers, the Miami Herald reports.
Shivji originally developed the technique to expose fishermen who were illegally hunting endangered shark species, then cutting them up to hide identifying features. But a local TV station convinced him to turn his talents to busting fish swappers. Soon stations around the country were calling for his services, mailing him frozen fish samples of what was supposed to be snapper, but turned out to be tilapia. Now he’s convinced it’s a huge problem, both because it defrauds consumers and complicates ocean conservation efforts. (Read more fish stories.)