Should You Avoid Frozen Fish If You Want Good-Quality, Nutritious Seafood?

You don’t need to avoid frozen fish if you want good quality and nutritional value, says Barton Seaver, the director of the Healthy and Sustainable Food Program at the Center for Health and the Global Environment at the Harvard T.H. Chan School of Public Health in Boston.


“The technology of freezing fish has evolved to the point where it’s comparable to, if not better than, fresh fish,” Seaver explains.

More than 85 percent of the seafood we eat in the United States is imported and the vast majority is frozen at some point, according to the National Fisheries Institute. Freezing preserves the nutritional value of the seafood.

“Historically, seafood was frozen as a last-ditch effort to keep it from spoiling. If fish wasn’t sold by Friday, it was frozen so it could be sold when demand was up. So it was a crappy piece of fish to begin with. But these days, fish is pulled from the water, filleted, and frozen within hours. That sounds pretty good to me.”

Stores that sell previously frozen fish, however, may be shortchanging the consumer of many benefits.

“If it’s frozen, it can stay in the freezer until you use it on your schedule,” says Seaver. “Why thaw it and start the process of spoilage? Retailers are playing to a taboo about frozen fish.”

To select good-quality frozen seafood:

  • Make sure the packaging isn’t torn or opened.
  • Avoid packages with frost, ice crystals, or liquid inside.
  • Avoid seafood that’s discolored.

Here’s a guide to the freezer shelf life of seafood, stored at 0 degrees or below, courtesy of the National Fisheries Institute:

Product Purchased Commercially Frozen for Freezer Storage Purchased Fresh and Frozen at Home Never Frozen, Thawed, or Previously Frozen and Refrigerated at Home
Fish Fillets and Steaks
Lean Fish
Cod, Flounder 10-12 months 6-8 months 36 hours
Haddock, Halibut 10-12 months 6-8 months 36 hours
Pollock, Ocean Perch 8-9 months 4 months 36 hours
Rockfish, Sea Trout 8-9 months 4 months 36 hours
Ocean Perch (Pacific) 8-9 months 4 months 36 hours
Fatty Fish
Mullet, smelt 6-8 months NA 36 hours
Salmon (cleaned) 7-9 months NA 36 hours
Crab (Dungeness) 6 months 6 months 5 days
Crab (king) 12 months 9 months 7 days
Crab (snow) 6 months 6 months 5 days
Crab, cocktail claws NA 4 months 5 days
Blue crabmeat (fresh) NA 4 months 5-7 days
Blue crabmeat (pasteurized) NA NA 6 months
Shrimp 9 months 5 months 4 days
Surimi products 10-12 months 9 months 2 weeks
Clams, shucked NA NA 5 days
Oysters, shucked NA NA 4-7 days
Lobster, live NA NA 1-2 days
Lobster, tail meat 8 months 6 months 4-5 days
Squid 8-9 months 4 months 36 hours
Breaded Seafoods
Fish portions 18 months NA NA
Fish sticks 18 months NA NA
Scallops 16 months 10 months NA
Shrimp 12 months 8 months NA
Smoked Fish
Herring NA 2 months 3-4 days
Salmon, whitefish NA 2 months 5-8 days

NA means the information is not available.


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43 Replies to “Should You Avoid Frozen Fish If You Want Good-Quality, Nutritious Seafood?”

  1. Good practical “Reality Meets Science” ™ approved info.
    Thanks Bonnie & CSPI
    Tom Rifai MD
    Harvard Medical School
    CME Online Course Director
    Lifestyle Medicine: Nutrition & The Metabolic Syndrome

  2. Good point. I ask for frozen seafood from the freezer rather than the stuff they have on display in the cooler. Most of the time they have what I want. If not I don’t buy it. I don’t shop daily for that day’s ingredients. It goes in my freezer so why buy thawed product and refreeze it ?

    1. you should NEVER refreeze fish that has been thawed–same with meat. once it’s cooked you can refreeze it, though that’s not a great idea taste-wise, it is safe to do.

  3. That all sounds great but aren’t we still dealing with the questions of where the fish comes from and the growing environment. Questions also about truth in the “type ” of fish!

  4. I totally agree with the frustration over supermarkets thawing frozen fish and then selling it. I shop once a week, and, often do not plan to have fish the night of grocery shopping. I try to buy fish at sale prices, and would love to stock up when there is a good deal, but won’t buy previously frozen thawed fish because I can’t refreeze it. FYI for those living close to a Trader Joe’s; they carry a great array of frozen seafood for reasonable prices.

  5. I won’t buy “previously frozen” anything unless I know it has been thawed that day and I plan to use it the same day. That’s just good common sense. Just like rinsing your fresh fruits and vegetables before using. Five minutes of time can save a week in the hospital or worse.

  6. I use nothing but Publix Whiting frozen fish fillets. They taste great EVERY time. Never waterlogged. They even improved on their vacuum seal process. Love it!

  7. I get frozen cod and flounder from Wal-Mart.
    The package says they are wild caught (Alaska), but it also says it is from China. Do you know if it is safe?

  8. I have found that buying a side of Coho commercially frozen,looks better, keeps better, than buying a side that is called Fresh Coho, portioning the fresh before freezing definitely not as good as the packaged frozen Coho/My local WholeFoods
    does not always have commercially frozen Coho, which I portion while frozen and put back in the freezer, and that had very high quality when I was ready to use my Coho portions.The fresh that I brought home, just was not as good
    in appearance.
    The reason given was this is the season for “fresh” Coho.”
    Therefore, no frozen.

  9. I was told this several years ago by the fish guy at Whole Foods. Now can we get some action against adding dye to make salmon obnoxiously red.

  10. Fish is so easy and quick to thaw………..why buy it thawed?
    I’m not sure it’s safe to re-freeze once it’s thawed.Isn’t there some bacterial growth in the thawing process?

  11. This article is very poorly thought out and in my opinion should not have been published. I am a long time subscriber and always thought that Bonnie Leibman’s articles were first rate. It’s hard to believe that she wrote this one. It declares that “Frozen fish is as good as if not better than fresh fish”. Is there any science to support this statement? I see none in the article.

    There is a quote from Barton Seaver- “But these days, fish is pulled from the water, filleted, and frozen within hours. That sounds pretty good to me”‘ but no mention of any research to support his opinion. It may “sound pretty good to him” but that doesn’t make it factually correct.

    Mr. Seaver also says “Retailers are playing to a taboo about frozen fish.” What does this meam? What is the taboo?

    The article also says “Stores that sell previously frozen fish, however, are shortchanging the consumer of many benefits.” I’d like to know what they are but they are not in this article.

    I think that an article like this weakens the credibility of “Nutrition Action”.

    1. The “taboo” is that consumers used to avoid frozen fish because it was old/not so great (before new tek where they are now able to freeze on the boat). So retailers are thawing frozen fish to cater to that old notion (fresh is better than frozen).

      There’s nothing wrong with the article. It’s a common sense piece.

  12. I ditto what Lou has just mentioned as I was also wondering. So what is the difference in nutritional value of fresh vs frozen? That is what is important to me. What do we lose in the freezing process?

  13. Mike B.

    Since so many species only have .1% left, we know according to Consumer Reports that the vast majority of seafood is mislabled- cheaper, more toxic varieties being substituted when we can’t see for sure what type of fish it is.

    Add to all the radiation being dumped into the ocean from the refissioned Fukishima meltdown and avoiding seafood is a life and death decision.

  14. This was not that helpful. What about buying fresh fish at Cosco…huge pieces and then freezing the fish as soon as you get home.We have been doing this routinely. Is there anything wrong?

  15. Man working in meat/seafood dept at Harris Teeter told me their sashimi grade tuna frozen to very low temp to reduce risk of parasites. Important to my family because we eat tuna tartar and pan seared tuna. I buy mine still frozen. He also suggested anything thawed in the seafood counter at least be pan seared to reduce risk of bacterial growth.

  16. OK, just avoid anything from non-regulated countries (China, Vietnam, Chile, Indonesia, Phillipines, etc.) even if it sez “wild-caught”…maybe, maybe raised in the cesspools or Mekong river (same difference) AND, much frozen pre-packed fish has no additives, EXCEPT “tripolyphosphate” “to retain moisture” That’s a salt, added to the pre-freezing soak so that it absorbs water…on thawing, you lose up to 1/3rd of weight in water!

  17. RE: frozen ‘Ahi (Tuna) watch out for “treated with Carbon Dioxide-to retain color”..Actually, it ADDS color-the most unnatural fluorescent-red fish you ever saw…and it is NOT “tasteless”…I can taste the gas, whether raw or cooked…which explains why stores in Hawaii that use it are making their poke’ (raw fish) with the most ungodly flavorings (Kim Chee sauce??)…to cover up.

  18. I find that most frozen fish seems to be sourced from China even if it says Alaska or West Coast. I do not want fish from China, especially Tilapia, and do not trust the packaging and labeling. I appreciate that the nutrients arguably are greater in frozen fish, but I won’t buy it.

  19. I enjoyed all of the responses. Was wondering if anyone has a source for wild Alaskan salmon that is frozen and KOSHER.I was buying this at Cosco but they have recently discontinued this. The kosher marking needs to be a U with a O around the U or a “backward” C with a little k inside. These are usually on the front of the pkg. at the side or bottom. Thank you.

  20. I have eaten fish forever; but noticing now that frozen fish is now
    a sensitive and growing intolerable food for my
    digestive ststem

  21. The problem is that you can not go to the store every day just for buying the piece of “fresh” or “freezed” fish you will eat.
    I buy some kgs of fish, previously filleted and than put it away in my freezer and take one dayly.
    Obviously, my freezer is not as good freezing as industrial ones, so maybe I am eating some how spoiled fish. But I do not see a practical or economical solution for this. I am sure most people do this here in South America or in Peru.

  22. is a wonderful source for information about what fish to purchase. They publish a guide which is updated regularly for each area of the country that can be printed out in pocket size to carry when you shop!
    I also agree with those who submitted comments about purchasing frozen fish from Trader Joe’s – I’ve never been disappointed with their selection or quality.

  23. Avoid crumb coated frozen fish unless you know for certain that it has been prepared in a reputable country such as Canada or the USA. Also do your research and buy the most sustainable varieties. Another point to bear in mind is to avoid bottom feeders(filled with more contaminants)..

  24. If the market has “previously frozen” fish, chances are they have frozen solid in the back that you can ask for. I do it all the time when fish is on sale.

  25. Is there a recommended way to thaw frozen fish? I usually place it in a pan of cold water and it thaws ready to cook in 45 mins. (10oz fillet of Haddock)

  26. I am blessed to live on the shores of Lake Erie. We fish for yellow perch and walleye and freeze it the same day it is caught in a baggie with water which creates a block of ice. How long should I keep this? Some years we have quite a bit of perch at the end of the season. Thanks.

  27. Where did I read that much seafood is caught (near Alaska) and flash-frozen at sea, then shipped to China where it is thawed and deboned and then refrozen and shipped back to the states? I wonder about this in light of the advice not to refreeze fish or meats.

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