Q. How can I be sure I’m always buying the freshest seafood?

Learn to judge the quality of fish and shellfish.

If you can see the whole fish, look for clear, bright, bulging eyes; bright-red, slime-free gills; firm flesh; brightly colored scales; and an ocean-fresh scent with no traces of a strong “fishy” smell. Fillets should be bright and uniform in color with firm, moist flesh. Avoid fillets with bruises, red spots, and yellowing or browning at the edges or flesh that is ragged, mushy, gaping, dry or “fishy” smelling.

A fresh, live lobster should curl its tail inwards when lifted, and a fresh, live crab’s legs should move continuously. Their shells should be hard, except for softshell blue crabs and new-shell lobsters. Live clams, mussels, oysters and scallops should have clean, unbroken, and moist shells that are tightly closed or close when tapped.

Shucked clams, mussels and oysters should be plump, with clear liquor free of shell particles or grit. Meats should have a clean ocean smell.

Fresh shrimp should be firm; the shell should be translucent and moist.

Look for frozen seafood that is frozen through and glossy. Avoid partially thawed fish and any fish with flesh bearing white or dark spots, ice crystals or freezer burn or dry, papery edges.

Q. Is fresh seafood better than frozen?

Not necessarily. Both fresh and frozen products can be of high or poor quality. Frozen seafood is often superior to its fresh counterpart when the product is harvested in a remote location and has spent several days getting to the store for sale. Frozen is often preferred for fish caught by boats that spend a week or two at sea, because frozen fish is of better quality than the fish caught early in the trip and stored in the hold until the boat returns to port.

Q. What is the best-quality seafood — FAS, previously frozen or fresh?

The answer depends on so many variables and is better to train your eyes and nose to judge quality.

Product quality depends on the species, the distance it had to travel to the store, how soon after harvest it was frozen, and what temperature it has been kept at since harvest.

Ideally, fish that are going to be frozen should be processed into its final form and frozen as quickly as possible under sanitary food handling conditions to as low a temperature as possible.

The freezing and storage temperature should be a minimum of 0 degrees F and preferably stored at minus 20 to minus 30 degrees F.

Ideally, fresh products are handled properly from harvest throughout the distribution process and kept at 32 degrees F. The shelf life varies by species and handling. New England groundfish, for example, that is good quality and held at 32 degrees F should be fresh for 14 days.

Q. I want to buy my fish now and cook it in four days. Will it still be safe to eat if it’s stored in the refrigerator?

Four days is pushing it for refrigerated fish. Keep it for one to two days maximum from the day of purchase and store it as close to 32 degrees F as possible. Most home refrigerators operate at 40 degrees F, which will cause the product to deteriorate.

Q. What fish are highest in Omega-3 fatty acids?

Common fish that are high in Omega-3s include: Swordfish, Atlantic Salmon, Silver Perch, Western Blue Grouper, Black Oreo, Blue Mackerel, Spanish Mackerel, and Gemfish.

Shellfish generally aren’t as high in Omega-3s as the above fish, but the ones with the highest levels include Oysters, Mussels, Squids, and Blue Crabs. All fresh fish are nutritious, and many have a good source of omega-3 oils. Even if it is not as rich of omega-3 as those listed above, eating a wide range of different seafoods and other natural foods will ensure a balanced diet.