The first and most important thing is to be sure you know your seafood dealer. Buy products only from approved, reputable licensed stores, markets or distributors with evidence of good refrigeration, icing and sanitation. Keep in mind that when someone is offering a really low price on an item there is usually a reason.
Fresh fish should have a mild sea breeze odor. A strong, fishy odor generally is not acceptable. Whole fresh fish should have bright, clear and shiny eyes. Scales should be shiny and cling tightly to the skin and the gills should be bright pink or red.
Fresh steaks and fillets should be moist and free of drying or browning around the edges.
Frozen fish should be received in undamaged boxes and must be frozen solidly with no evidence of freezer burn.
Fresh “shell on” products such as mussels, clams and oysters should be purchased alive. Live crabs will show leg movement and lobsters will curl their tails tightly beneath them when handled.
Freshly shucked oysters and scallops have a fresh odor and should be surrounded with a clear, slightly milky or light gray liquid. If in doubt about the source of raw oysters, clams and mussels, ask your supplier or seafood market personnel to show you the certified shipper’s tag that must accompany shell on products.
Frozen shellfish should always be received in vacuum packed moisture proof containers.