Forget the smell test.

Diners today can barely trust their own eyes when it comes to divining what type of seafood is poised to pass their lips.

The issue, tagged “seafood fraud” by industry watchdogs, touches on a range of interrelated concerns from food security to basic economics.

A broad coalition of sustainability-minded chefs, seafood wholesalers and advocacy groups are fighting to improve traceability and accountability in the seafood-marketing realm.

And they’re doing so, at least in part, by dispelling the myth that seeing necessarily correlates to believing.

Hook, Line and Sinker

As part of an ongoing effort to expose suspect seafood offerings, the international conservation group Oceana snatched up 1,215 samples from 674 retail stores scattered across 21 states. It discovered that roughly one-third of the purchases were mislabeled, according to existing Food and Drug Administration standards.

The most commonly counterfeited fish in the bunch: red snapper. Only seven of the 120 samples sold as such were the real deal.

Oceana Campaign Director Beth Lowell says the intentional swapping of ocean species affects all, from penny-pinchers to the nutrition-minded.

“Seafood fraud can certainly thwart your best efforts,” she told a crowd of nearly 100 participants who recently gathered at the National Aquarium for a tasting menu of mystery fish (more on that in a second).

Oceana warned Congress about the dangers of mislabeling last spring, huddling with Democratic Rep. Edward J. Markey, who’ll soon represent Massachusetts in the Senate, and House Minority Whip Steny H. Hoyer of Maryland, as well as Senate Democrats Mark Begich of Alaska, Barbara Boxer of California and Sheldon Whitehouse of Rhode Island, about the largely under-the-radar issue.

The lobbying effort spawned the Safety and Fraud Enforcement for Seafood Act, bicameral bills (HR 1012, S 520) calling for enhanced identification and traceability standards that were reintroduced this March.

While he is sympathetic to Oceana’s mission, Joe Lasprogata, vice president of new product development at Samuels & Son Seafood, cautioned that the group might be casting too wide a net. “Any time you’re not getting what you pay for, it’s a problem,” he asserted. “But how big it is is debatable.”

The Whole Story

Xavier Deshayes, executive chef at the Ronald Reagan Building and International Trade Center, admitted that even though he’s around seafood all the time, identifying a popular species once it’s been filleted — much less after it’s fully prepared — could be a daunting task.

“Once it’s cooked … it’s going to be difficult for you,” he said, adding that spicy sauces provide the perfect camouflage for sneaking carefully selected imposters past unsuspecting diners.

Deshayes tested that theory at the third annual Fresh Thoughts dinner. The event, sponsored by Oceana and hosted at the National Aquarium in Washington, D.C., featured a multi-course tasting of authentic seafood alongside cut-rate doppelgangers.

Attendees — including National Aquarium staff, public policy advocates, a young woman studying environmental science and a college-aged gentleman who shared his love of fishing area waterways — began getting schooled in the art of epicurean misdirection the minute they stepped into the tank-lined exhibit hall.

One chart displayed filets of commonly served fish — Pacific cod, tilapia, escolar, rockfish, farm-raised Atlantic salmon — next to lesser known knockoffs. (Very hard to differentiate, especially for an untrained eye.)

But an ice-filled bowl of genuine (halibut, snapper, wild king salmon) vs. fake-out (fluke, corvine, farm-raised salmon) filets proved to be the real conversation starter.

“I’m not even sure you could trust Whole Foods, but maybe that’s just me,” one attendee said, second-guessing her own shopping habits after puzzling over the mystery fish.

Servers floated around with complimentary beverages and gourmet nibbles.

A swallow of shrimp ceviche was dominated more by accompaniments (lime bath, diced onions) than the main event (neutral shellfish).

Caviar-topped deviled eggs were delightful, briny orbs atop creamy egg mousse.

A spoonful of crab mac and cheese featured rich, cheesy elbow macaroni enveloping finely shredded savory crab.

Or so we all thought.

“Tonight, I lied just to play with you,” Deshayes announced once everyone was seated, finally clueing in guests as to what they’d actually let slide down their gullets.

The ceviche sported farm-raised shrimp (impossible to tell), the caviar was actually paddlefish roe from Missouri (somewhat stunning), and the mac and cheese had been seeded with imitation crab (par for the course).

But Deshayes was just getting started.

The deception continued as patrons were plied with cleverly concealed stand-ins. Black grouper from Panama City, Fla., cooked escabeche style, was escorted by a similarly prepared weakfish from Port Pierce, Fla. My tablemates leaned toward the fatty, oilier portion on the left being the grouper; I actually preferred the leaner, flakier cut on the left, which turned out to be the weakfish.

The salmon course proved tougher. Each plate was piled with pan-roasted Alaska wild king salmon from Kodiak Island alongside farm-raised salmon from the east coast of Canada.

“I don’t know,” a fellow journo offered after examining slices of each up close.

“I’m clueless,” an Oceana aide said.

“Well, they all taste delicious,” a punchy layman proclaimed.

We finally reached a consensus, properly distinguishing the wild salmon (terrific sear, stronger taste) from the fake (burnt orange color, buttery flesh).

The final exam put the elusive red snapper up against farm-raised tilapia from Ecuador, masking both in a vibrant chimichurri crust. The snapper shined through, revealing a heartier, gamier taste than the more innocuous interloper.

Reeling Things In

Lasprogata acknowledged being familiar with Oceana and its study, but indicated that he doesn’t buy the arguments wholesale. He projected that 5 percent to 6 percent of the industry might be deliberately trying to overcharge for an inferior product.

“As many proteins increase in price, it’s an opportunity for the unscrupulous,” Lasprogata argued. “And that’s the problem that needs to be addressed.”

But he’s more concerned that the purported “fraud” might have more to do with semantics than actual seedy behavior.

Lasprogata said Samuels & Son Seafood does its best to educate its customers, but suggested that the information doesn’t always trickle down to frontline restaurant and retail staff — particularly inexperienced, minimum-wage servers and counter staff.

“If you don’t know what you’re looking at  . . .  you could easily make a mistake,” he said of the potential domino effect of a misidentified portion. Likewise, there are cultural issues that must be considered, since any given fish could be known by different names around the globe.

“The one thing that is confusing about this issue is not mislabeling but regional identification,” he counseled.

To that end, he said Samuels & Son has been working with the Pennsylvania branch of the FDA to develop a DNA library to better identify all manner of seafood.

Jonathan Pearlman, director of operations at Congressional Seafood, said his organization has fully embraced transparency, tagging its inventory with scannable QR codes that track each item “from hook to plate.”

ProFish President Gregory Casten and John Rorapaugh, ProFish’s director of sustainable dining initiatives, are also involved in the fight, working both internally and marketwide to groom better informed consumers.

But they, like Lasprogata, have concerns about picking the right targets.

“The fraud of mislabeling  . . .  is committed strictly for monetary gain and as such it can be found at all levels of fish handling. Our observation is that the most blatant abuse comes not from those stages in the course of getting a fish to market, but at either the unscrupulous last dealer to the retailer or with the retailer themselves,” Team ProFish warned in an email from Casten and Rorapaugh.

The wholesaler has instituted a slew of safeguards to halt such shady dealing, ranging from the adoption of morality clauses in contracts to widespread DNA testing and its homegrown, traceability-advancing FishPrint system.

ProFish is pleased Congress has shown an interest in tightening regulatory safety nets, but stressed that there is more work to be done.

“It is key that a labeling standard is decided upon and a technology led system is adopted and built by the industry,” Team ProFish counseled.

In the meantime, they urged consumers to do their homework when contemplating catch-of-the-day specials.

“Ask the restaurant or retailer a few questions: Where was this fish caught? How was this fish caught? Is it farmed or wild?” Team ProFish advised. “Not that there are good or bad answers in these cases; you just want to make sure the person you are trusting your meal to can answer them.”