How to select fresh and frozen seafood safely

Only buy fish that is refrigerated or displayed on a thick bed of fresh ice (preferably in a case or under some type of cover). Because the color of a fish can be affected by several factors including diet, environment, treatment with a color fixative such as carbon monoxide or other packaging processes, color alone is not an indicator of freshness. The following tips can help you when making purchasing decisions:

Fish should smell fresh and mild, not fishy, sour, or ammonia-like.

A fish’s eyes should be clear and shiny.

Whole fish should have firm flesh and red gills with no odor. Fresh fillets should have firm flesh and red blood lines, or red flesh if fresh tuna. The flesh should spring back when pressed.

Fish fillets should display no discoloration, darkening, or drying around the edges.

Some refrigerated seafood may have time/temperature indicators on their packaging, which show if the product has been stored at the proper temperature. Always check the indicators when they are present and only buy the seafood if the indicator shows that the product is safe to eat.

Fresh fish and fish fillets sold as “Previously Frozen” may not have all the characteristics of fresh fish (e.g., bright eyes, firm flesh, red gills, flesh, or bloodlines), however, they should still smell fresh and mild, not fishy, sour, or rancid.

Source: https://www.fda.gov/food/buy-store-serve-safe-food/selecting-and-serving-fresh-and-frozen-seafood-safely