Seafood is an important part of a healthy diet. It's been attributed to healthy hearts and proper development in children. While eating fish and shellfish is important, it's equally important to take precautions to avoid foodborne illness. Here are the FDA's tips for selecting, serving, and storing seafood safely.

Start right when you buy the fish. 
Only buy seafood that is stored on plenty of ice. If it looks slimy or smells sour, steer clear. If you're buying fish that has been frozen, make sure it's below the frost line but does not have too many ice crystals on the packaging — it may have been sitting for too long.

Immediately put fish on ice or in the fridge when you get home.
If you plan on using the fish in more than two days, package it in a moisture-proof container and freeze it.

Store raw fish and cooked fish separately.
When you plan on cooking the fish, let it defrost in the fridge overnight.

Seafood is safe to eat when the internal temperature has reached 145ºF.
The best way to check is by using a food thermometer. The fish should not stay out of the fridge for more than two hours once it has been cooked. 

· Fresh and Frozen Seafood: Selecting and Serving It Safely [U.S. Food and Drug Administration]