Shrimp, prawns and fish farming

Image by Getty Images via @daylife

A salmon farm in Scotland.

I always look for wild-caught seafood and try to avoid fish fillets from large species that contain a lot of harmful mercury, such as swordfish and Chilean sea bass.


But not all farmed fish is bad.


Whole Foods Market pledges all of the farmed fish it sells is raised on feed that doesn't contain antibiotics, added growth hormones, or "poultry and mammalian by-products."


I buy wild-caught salmon, haddock and flounder fillets at Costco Wholesale in Hackensack, but this merchant doesn't tell you much about how its farmed fish is raised.


Both Whole Foods and Costco sell farmed salmon that is artificially colored by chemicals in the feed, because the confined fish don't eat their wild cousin's natural, colorful diet of shrimp and krill.


The Monterey Bay Aquarium Seafood Watch usually recommends fish farmed in the United States, but not imports.


Farmed shrimp


Costco sells Black Tiger EZ Peel shrimp imported by the Mazzetta Co. of Highland Park under the trade name SEAMAZZ.


In an exchange of e-mails, Mazzetta's Jeff Goldberg said Costco had mislabeled U-15 prawns sold in a SEAMAZZ bag as having been raised in Bangladesh.


All of the farmed shrimp supplied to Costco are raised in Indonesia and Vietnam without harmful additives, he said.


Large, head-on U-4 prawns I bought at Costco were treated with a preservative to prevent the heads from turning black, Goldberg said, but all others are sold without heads and are not preserved in any way.


"We do not use any preservatives or antibiotics in the production of the shrimp we sell Costco," he said, "[and] the only additive used during production is salt."


Costco often labels SEAMAZZ shrimp as "prawns."


Goldberg said: "The term prawn is very misleading, but is generally used in Europe or by some restaurants in the U.S. to make shrimp sound 'sexier.'


"We stick to the term shrimp, which is very clear."


Seafood Watch recommends consumers avoid imported Black Tiger shrimp, whether farmed in "open systems" or wild-caught.


Although Costco and other food stores are required to tell consumers where seafood comes from and whether it is wild-caught or farmed, restaurants are under no such obligation, and few restaurant reviewers include that information in their appraisals.