This article was originally published February 6, 2013.

INDIAN ROCKS BEACH, Florida -- Whetherit's broiled, blackened, or fried, grouper always seems to be a favorite at seafood restaurants around the Bay Area. But is the fish on the menu what winds up on the plate?

Last year, the conservation group Oceana found that 31 percent of seafood sold in South Florida restaurants, sushi venues, and grocery stores was mislabeled (grouper was mislabeled at a lower level: 18 percent).

10 News decided to see if Bay Area restaurants were selling what they're advertising. One of the restaurants we tested was Crabby Bills, which has locations in Indian Rocks Beach, Clearwater Beach, and St. Pete Beach. Grouper is one of its most popular items.

"It's probably six or seven percent of our total volume," said Crabby Bills CEO Matt Loder.

Loder told 10 News he knows he's serving real grouper because he trusts his suppliers. But he can't vouch for all of his competitors.

"That's what makes us so angry when we see other people fraudulently selling something else and, of course, charging less for it. It makes us look like we're the bad guys in this deal," said Loder.

10 News decided to check for fakes by ordering grouper sandwiches from ten different restaurants in the Bay Area. We brought them to the College of Marine Science at USF-St. Petersburg for DNA testing. The crew there can tell if the samples are real grouper or something cheaper, like tilapia or Asian catfish.

"Grouper is generally a thicker, flakier white filet," said Distinguished Professor John Paul, PhD. "Some of these other catfish are thin filets."

But Paul said most grouper lovers probably can't tellif their fish is fake once it's cooked. "When something's been blackened, buttered, and sauced, it all tastes like grouper."

A week after taking the samples to Paul's lab, we got the results, and they were encouraging: all of them turned out to be real grouper. The result from the Hurricane Restaurant in Pass-a-Grille didn't surprise general manager Rick Falkenstein.

"Oh, great! I know that," he said.

But Falkenstein also knows there are times when a competitor might not pass the test, and it makes him angry.

"How can someone in our industry sell something that's a fake and stand up and seat guests at their table? They deserve what they get," said Falkenstein.

A few years ago, the state started cracking down on restaurants that misrepresented food items on their menu. More than 40 Bay Area restaurants were eventually cited for advertising grouper and selling something else. One of them was Bella Habana in St. Pete Beach. But that was in 2006, when it was under old management. Mariano Alvarez bought Bella Habana in 2009.

"I've never had a problem," said Alvarez. "I will not serve anything that's not what it's supposed to be. Period!"

USF's College of Marine Science has developed a hand-held device that can test grouper DNA in less than an hour. Professor John Paul said the university hopes to eventually make the technology available to restaurant owners so they can verify fish at the dock.

"They want to know what they're getting before they put their money out," said Paul. "So, within 45 minutes to an hour, they'll have a correct answer."

For customers, Paul has another suggestion: check the price. If a restaurant is selling a grouper sandwich for five dollars, it's probably not grouper.

"I would be very suspicious," said Paul.

Here are the results of the restaurants 10 News tested, and the price for their grouper sandwiches in mid-January. (Prices can vary, and some of the restaurants may take grouper off their menu if the price their suppliers are asking is too high.)

  • Babalu, St. Petersburg -- Red Grouper $12.95
  • Frenchy's Rockaway, Clearwater Beach -- Red Grouper$10.95
  • Crabby Bill's, Clearwater Beach -- Red Grouper $12.99
  • Colonnade, Tampa -- Red Grouper $12.99
  • The Hurricane, Pass-a-Grille -- Red Grouper $10.75
  • Dockside Dave's, St. Pete Beach -- Black Grouper $12.95
  • Jimmy Guana's, St. Pete Beach -- Red Grouper $10.95
  • The Pub, Indian Shores -- Red Grouper $12.95
  • Harvey's 4th St. Grill, St. Petersburg -- Red Grouper $11.95
  • 4th Street Shrimp Co., St. Petersburg -- Red Grouper$11.99
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