Not only is eating fish not the most sustainable of food choices, it's likely a rip-off. If you're eating a pricey fish like cod or salmon, there's more than a one in five chance that it's something much cheaper. The FDA, though, is developing a new regulatory program to fight fish fraud. The agency is building a library of fish DNA that it can use to test samples of raw, frozen, steamed, or deep-fried fish and determine the sample's species.

This genetic identification process is known as DNA bar coding, and it's gotten so cheap that the FDA can do a bar code test for about $10 a sample. That might keep sellers from trying to pass off fishy fish, which is pretty gross, as an ocean scientist explained to The New York Times back in May:

“If you’re ordering steak, you would never be served horse meat,” said Dr. Hirshfield of Oceana. “But you can easily be ordering snapper and get tilapia or Vietnamese catfish.”

The agency isn't just concerned about overpriced snapper substitutes, though. Mislabeled, toxic fish has sickened people in the past.

One point of order: if your fish doesn’t taste like it's supposed to, do not cut off a sample and send it to the FDA! They don't want your half-eaten dinner! You can file a complaint, though, and the agency might investigate.