Did you ever wonder if a restaurant's crabcake was made with Maryland crab or some foreign import? Or if that was really red snapper you bought, or an impostor? 

A bill introduced Wednesday in Annapolis would make it illegal for restaurants or markets to mislabel the seafood they sell, and moreover would require them to specify where their crabmeat came from.

"If I go to a restaurant and order a 'Maryland-style' crabcake, I'd like to know if it's made with Venezuelan crabmeat," said Del. Eric G. Luedtke, the bill's sponsor.

Luedtke, a Montgomery County Democrat, said investigations have found a significant share of seafood sold in restaurants is mislabeled. Such bait-and-switch winds up costing consumers more, he said, and sometimes can even have health consequences.

A study by Oceana, a Washington-based conservation group, found through DNA testing that one-third of more than 1,200 seafood items bought in stores nationwide were mislabeled, according to guidelines form the U.S. Food and Drug Administration. In the Washington area, 26 percent of fish was mislabeled, the group said. Snapper and tuna were among the most frequently misidentified products.

Luedtke said his bill is modeled on a seafood labeling law in Washington state.  It would require the species and common name of any fish or shellfish sold in the state be identified on a restaurant menu or on a sign in the market.

It would also require identifying the source of crab products by state or country, and bar selling anything as "blue crab" if it wasn't made from Callinectes sapidus, the species native to the Chesapeake Bay and the Atlantic and Gulf coasts. The Department of Natural Resources, which already encourages restaurants and markets to carry locally caught seafood through its "true blue" campaign, would be directed to draw up labeling regulations.

"Any time we can improve the quality of information consumers are getting, it's a good thing," Luedtke said.

Oceana supports Luedtke's measure as an antidote to mislabelling that it says often amounts to seafood fraud. The group has petitioned Congress to pass federal labeling legislation, and gathered signatures in support from 450 chefs nationwide, including 25 from Maryland and 10 from Baltimore. With no action to date in Washington, Oceana's campaign director Beth Lowell said action at the state level can help.

"When ordering Maryland's famous blue crabs, I want to be certain that I'm actually having crabs from Maryland that were caught in the Chesapeake Bay and that I am supporting local watermen," Lowell said.

Jack Brooks, co-owner of J.M. Clayton Co., a crab processor in Cambridge, and president of the Chesapeake Bay Seafood Industry Association, welcomed the bill, saying Maryland consumers often unwittingly buy or eat crabmeat imported from South America or Asia, hurting local watermen and businesses like his.

"The poor consumer is the one really taking it on the chin here," he said. "It's so sad they really don’t know the origin of seafood."

But Brooks called "problematic" one provision in the bill that would require U.S.-caught crab products be labeled by their state of of origin.  He said his business processes crabs from Virginia as well as Maryland, and that some of the watermen he buys from have licenses to work in both states.

Melvin R. Thompson, senior vice president with the Restaurant Association of Maryland, said he couldn't comment on the bill until member restaurateurs have a chance to review it.