Want to know what kind of fish is on your plate? So do Mario Batali, Rick Bayless, Thomas Keller and a who's who list of major chefs who are taking a stand against seafood fraud.

More than 500 restaurant owners, culinary industry leaders and chefs - including Daniel Boulud, Jacques Pepin and Eric Ripert - signed a petition posted by conservation advocacy group Oceana.

The letter asks the U.S. government to prevent unapproved fish from reaching the American market by mandating tracing programs.

American consumers are eating more imported seafood, according to the petition.

But after leaving the ocean, fruits de mer traverse an increasingly complicated supply chain, "increasing the risk of fraud each step of the way and making it more difficult for us to make eco-friendly choices," according to the petition.

Information about a particular fish's origin is often limited, according to the chefs. The petition cites studies that up to 70 percent of seafood is mislabeled, with common and inexpensive species often disguised as more in-demand varieties.

With more companies such as Target committing to sustainable and traceable fish, the calls for a more transparent system are swelling.

Tests this spring at Los Angeles sushi bars, restaurants and grocery stores showed that 55 percent of 119 fish samples were misidentified, according to Oceana. "Overglazing" fish by adding layers of ice and "soaking" scallops to boost bloat are also common fraudulent practices, regulators have said.