Some of the contaminated feed was tracked to six Washington state hatcheries and was withdrawn immediately.
The Canadian-made meal included what was purported to be wheat gluten, a protein source, imported from China. However, the material was actually wheat flour spiked by the chemical melamine and related nitrogen-rich compounds to make it appear more protein-rich than it was, said officials.
The farmed fish are the third food animal to be given contaminated feed - pigs and chicked have also been given feed containing the chemical - but the level of contamination is not thought to pose any danger to human health, said Dr. David Acheson, assistant commissioner for food protection at the US Food and Drug Administration (USFDA) .
It wasn't immediately clear if any of the farmed fish entered the food supply. Most of the farmed fish in Northwest stores is Atlantic salmon, and many stores have increased labeling to differentiate farmed vs. wild-caught salmon.
"We make sure our customer is fully aware that a fish is a farmed product, or that it is wild fish," said Michael Batton, a head chef at the QFC-Harvard Market in Seattle.
News reports on Tuesday identified two Canadian companies -- Westaqua Commodity Group and Skretting -- that distributed fish feed spiked with the melamine. Both companies distribute feed to salmon farms as well as trout and other types of fish farms.
Skretting said has recalled a batch of its feed shipped to the United States after USFDA testS found traces of melamine, although it had received no complaints of ill effects for fish.
Skretting is a subsidiary of Nutreco, a multinational company based in the Netherlands that is involved in fish and other animal feed manufacture, as well as fish farming.
The food used at Washington state hatcheries was a starter feed eaten by fall chinook salmon, steelhead, rainbow trout, brown trout and possibly chum salmon. There were no reports of any abnormalalities among the several million fish estimated to have consumed this feed. John Kerwin, hatchery division manager for the state Department of Fish and Wildlife said the starter mix is fed to the young fish only for a few weeks at a time before they move on to other feeds.
Some of the contaminated feed also went to Oregon, where it was distributed to hatcheries that raise salmon and other species that are released into the wild. Last week, an Oregon hatchery was informed that feed from Skretting was contaminated with melamine. However, Oregan officials said that no ill effects were seen in any of the 870,000 spring chinook produced for the Willamette River system which may have eaten the contaminated feed.
The Skretting feed was shipped to six other Oregon hatcheries. The feed at those hatcheries has yet to be tested.
Melamine, a chemical found in plastics and pesticides and not approved for use in pet or human food in the United States. Since March 16, more than 100 brands of pet food have been recalled.
Source: The Seattle Times