NEW YORK — Fresh wild salmon from West Coast waters once generally migrated eastward in cans. But concern about the safety of farm-raised fish has given wild salmon cachet.

Chefs praise its texture and flavor as superior to the fatty, neutral-tasting farmed variety, and many shoppers are willing to pay far more for it.

"Fresh wild salmon" is abundant, even in the winter, when little of it is caught. In fact, it seems a little too abundant.

Tests performed for The New York Times in March on salmon sold as wild by eight New York stores, at an average price of $19 a pound, showed that the fish at six of the eight were farm-raised. Farmed salmon, raised in floating pens and available year round, sells for $5 to $12 a pound in the city.

The findings mirror suspicions of many in the seafood business that wild salmon could not be so available from November to March, the off-season.

Wild salmon become pink by eating sea creatures such as krill, which contain a carotenoid called astaxanthin. Farmed salmon are naturally grayish, but turn pink when they are fed various sources of astaxanthin, including one that is chemically synthesized and others that originate from yeast or microalgae. The coloring can be measured in laboratory testing.

With East Coast wild salmon all but extinct and West Coast catches restricted by quotas, farmed fish constitute 90 percent of U.S. salmon sales.

Yet last month, when fresh wild salmon should have been scarce, 23 of 25 stores checked by The New York Times said they had it in stock.

The newspaper sent random samples of salmon bought March 9 to Craft Technologies in Wilson, N.C., for testing, using a method with which scientists at the Food and Drug Administration (FDA) have identified wild and farmed salmon.

Only one sample tested wild. Six tested farmed. Another sample seemed to show that the fish had been farmed at one time and had escaped into the wild, not an uncommon occurrence.

Two scientific studies in the past two years have reported that farmed fish contain more PCBs and other contaminants than wild fish, and many studies have called farming practices an environmental hazard.

Told of the results of the fresh-salmon tests, Gretchen Dykstra, New York's commissioner of consumer affairs, said her agency would "be investigating whether these stores are in fact improperly baiting their customers." Mislabeling food is against federal law.

Officials at the stores had a variety of explanations.

One said his sales clerks "must have gotten the salmon from the wrong pile in the back."

Another said four of his vendors could not provide a paper trail. He said he now wanted proof of the source of the fish from his vendors, and would have his salmon spot-tested.

Still another said he had narrowed the source of his fish to two Northwest vendors and had suspended links with both.

Laura Fleming, a spokeswoman for the Alaska Seafood Marketing Institute, a state agency that promotes wild seafood, said, "The symptom is not confined to Manhattan."

"We've had calls from various places around the country ... from indignant fans telling us that stores are promoting product as wild Alaskan salmon when in fact it is not wild salmon at all," Fleming said.

Federal regulations governing country-of-origin labeling took effect April 4. They require fish to carry a paper trail back to the source, but they apply to full-service markets such as groceries, not to fish markets.

Even renowned chefs such as Eric Ripert of Le Bernardin and David Pasternack of Esca, who pay top dollar for the choicest seafood, could not visually distinguish between wild and farmed salmon. After the fillets were cooked, however, they could taste the difference.

"The most obvious clue is flavor," Fleming said, "but by that time, it's too late."