Just before opening or cooking seafood, scallops, mussels, clams, or oysters in the shell should be scrubbed under cold water to clean them. Soaking seafood in water with flour or cornmeal to encourage the creatures to eat to clean out the grit only shortens their life. Store frozen fish and salmon and seafood at zero degrees or below. For fish that is purchased frozen, it is recommended that it be used within two months. If your home freezer door is opened frequently, it is recommended that fish and slmon be used within two weeks for optimum taste and nutrition.