Go to the Freezer Section
When I am far away from the sea, I never bother with the "fresh" fish displayed in the supermarket. It will most likely stink, be days old or worse -- thawed, pre-frozen seafood. Ick. Americans who live inland don't eat seafood like coastal people do, so the supermarket will not sell enough seafood to really get their hands on the top-quality fish. Frozen fish, on the other hand, won't be so damaged.
The exception to the "No Fresh Fish" rule in supermarkets is where there is a local freshwater fishery. In the Northern states, walleye and yellow perch are often available -- buy them whenever you can, as they are world-class fish. Smoked whitefish ("chubs") are another local favorite in some states. You can get great sturgeon far inland in the Pacific Northwest. And remember that farmed catfish and trout are available nationwide, and the methods used to raise either fish are, for the most part, environmentally friendly.
When you are over at the freezer section, look at the labels. The first thing you should look for is an indication that this seafood was caught in America, Canada, Iceland or New Zealand. These countries have the best fishing management practices in the world, and in the case of American seafood, you are helping create jobs here. Many other countries are over-fishing their part of the oceans. And a special note on farmed shrimp from Southeast Asia: These shrimp are loaded with chemicals and pesticides, and are so horrid for the environment -- and the local people -- that I recommend you avoid them altogether.
Sorry, but unless you have access to a really good supermarket in a major inland city, don't buy shellfish. That means no "fresh" clams, oysters, mussels or lobsters. Even lobsters, which will be sold live in tanks, lose a lot of quality when they languish in a tank. Again, Easterners eat a lot of lobster, so the stock moves fast. A lobster in a tank in Iowa could have been sitting there for weeks. And it is tough to ship live clams, oysters and mussels long distances without losing quality: It can be done, but you'll know that the quality is high by the price and the smell. My advice? Buy frozen, or stick to fish.
Look for Value-Added Seafood
Smoked fish and canned fish travel well, and many supermarkets carry excellent options. I rely a lot on either local smoked fish such as whitefish or trout, or the smoked salmon that's available everywhere. As for canned fish, look for European tuna or sardines or anchovies; this is an exception to the "buy American" rule. The tuna in bags is generally good, as is American tuna stored in oil. The water-packed stuff may save you a few calories, but it is generally nasty tasting.
Choosing the Right Frozen Fish
Not every fish freezes well. Oily fish such as yellowtail or some tuna are generally unsuited to freezing, and even salmon can suffer if frozen too long. Look instead for these common supermarket fish:
- Pacific cod or pollock
- Sockeye salmon (it's leaner than king salmon)
- Yellowtail tuna (generally cut from lean portions)
- Swordfish or Thresher shark
- Pacific halibut
- "Sole," which is really flounder
- "Snapper," which is rarely true red snapper
- American shrimp
- American squid
- Alaskan king or snow crab
- Vacuum-packed sea scallops (they must be sealed to be worth buying)
Look for the Seal
As I mentioned above with sea scallops, vacuum-sealing is a sure sign of good frozen fish. I never buy frozen fish that has simply been placed on a styrofoam tray, covered with plastic wrap and tossed in the freezer -- that is a recipe for freezer burn. The only exception to the vacuum-seal rule is when the package explicity says the seafood was "flash frozen," which means it was frozen right after it was caught in a super-cooler. Once frozen this way, it can be placed in a sealed bag without a vacuum seal and stay in good shape for several months.