In theory, aquaculture is a perfect solution to declining natural sources and the capriciousness of supply: The fish farmer can control the size of his schools and arrange for them to mature when the market is right.
“But in practice it has taken time to pay out because of start-up problems,” says Joyce Nettleton, director of science communications for the Institute of Food Technologists. She has studied the aquaculture industry. “Catfish and trout are flourishing, and on the coasts salmon are doing well, but even these are not without their problems.
“Birds that feed on the fish are a big problem, especially in shallow ponds,” she says. “And there is disease.”
A dozen or so years ago, large food companies got into aquaculture but pulled out because they couldn’t make it pay fast enough, Nettleton says. Getting the fish to the right size at the right time was not as easy as expected, and overstocking was a problem. People didn’t buy what still is a relatively expensive food. “The price was never going to come close to that of chicken,” she says.
Another problem is that you can’t always cultivate the same species that grow wild, Nettleton says. “There is no farm substitute yet for cod, for instance.”
However, some fish farmers are experimenting with ways to raise cod and halibut, especially in Canada, where the government has almost shut down cod fishing, says David Harvey, a USDA aquacultural economist. In the Midwest, farmers are experimenting with yellow perch and walleye.
Aquaculture is one answer to some of the safety questions about fish from polluted environments, says Nettleton.
Many of the farm-raised species are very sensitive to water quality, she says. “Hatchlings won’t survive if the water isn’t good. But one of best new aspects of fish in aquaculture is that water quality is high.”
How such fish taste also depends on water and feed, Harvey says. Fish raised in confinement can acquire off-flavors if the water is not kept fresh: Buyers and distributors take pains to assure that the fish they buy lives up to flavor standards, he says.
The nutritional quality of farmed fish on the whole is about the same as those in the wild, Nettleton says, though farmed catfish, for instance, has more fat.
“On the other hand,” Nettleton says, “farmed catfish are free of off-flavors and odors.”
