Common Additives to Watch Out for on Seafood Packaging

Frozen seafood in a grocery store

A source of protein, micronutrients and essential fatty acids, seafood is a great substitute for red meat. But how do you know that you’re getting the benefits of healthy fish, without any unwanted additives? While packaged meals make for quick and easy dinners, they often contain plenty of unhealthy ingredients, from chemicals to preservatives.

For healthy meals, the best choice is to start with fresh or frozen fish. Here are some things to watch out for on the packaging of seafood products, or to research at home before you hit the grocery store.

Antibiotics and Hormones

Not all seafood is created equal. Depending on where the fish is raised and under what conditions, fish farmers may use antibiotics and growth hormones to increase yield. Look for seafood varieties labeled “all-natural” and always make sure any claims are verified by a reputable third-parties such as the Aquaculture Stewardship Council.


While they are a convenient favorite, many frozen or pre-packaged seafood products contain lots of sodium. Specifically, watch out for:

  • Fish sticks — more than 500 milligrams for five frozen fish sticks
  • Smoked salmon (lox) — about 1,700 milligrams per 3-ounce serving
  • Canned fish such as tuna, salmon and crab — as much as 300 milligrams in 3 ounces


frozen fish sticks

Sodium acts as a preservative, but it’s not the only one used. Other preservatives you may see listed on packaging include: erythorbic acid, sodium erythorbate and sorbic acid.

To avoid preservatives and excess sodium, choose pre-made items less often. Instead, stock up on fresh or frozen fish and make your own healthier variations. (Try this recipe for homemade, baked fish sticks from Eating Well.)


Some producers use sodium tripolyphosphate (STPP) to improve the retention of water by the protein in the fish. This makes fish appear firmer, smoother and glossier—and makes older fish appear fresher than it really is. It’s commonly used on scallops, shrimp and flaky filet-type fish such as flounder. It also makes the fish heavier when it is weighed (which increases the cost) and may be a neurotoxin. STPP is not required to be listed on packaging, so do some research in advance or ask your grocer if the fish is being sold “dry”. In industry terms, “wet” fish is that which has been soaked in phosphates.

Artificial Coloring

Appetizers with smoked salmon

Some fish farmers are using artificial coloring to make their fish look extra fresh and appealing. Farmed salmon, for example, is naturally light pink. However, the fish are fed pellets which contain Carotenoids to give it the rich red hue characteristic of wild salmon. This is just another reason to look for “all-natural” on the packaging.

Fish can also be sprayed with carbon monoxide to enhance the color, kill parasites and give it that “just caught” look. This is common among fish imported from China; fish from Latin America is not sprayed with carbon monoxide, so it is a better choice. Here’s what to look for to tell!

Be a Conscious Consumer

Seafood is fantastic, but it’s always important to be conscious about what you are buying. Look for seafood labels from third-party regulators that provide assurances that specific health and safety certifications are being met. Some to watch for include:

With a bit of preparation and awareness, you can be assured the seafood you are buying is providing the best nutrition for you family. And when in doubt, it’s always better to buy a fresh or frozen fish fillet and prepare it yourself. It doesn’t have to be a challenge! Check out these quick and easy fish recipes to get started.

If you’re unsure or can’t find the information you’re looking for on the packaging, talk to your local fishmonger. They know their product best, so they’ll be able to answer any questions you might have and guide you in the right direction.

Photo credits: Shutterstock / Vereshchagin Dmitry, Shutterstock / PosiNote, Pixabay