Although frozen fish can stay safe indefinitely, it begins to degrade in quality after three to six months. This storage time depends on the quality of the fish and how well it was packaged.
Frozen food should be stored at 0 degrees Fahrenheit to maintain maximum quality and safety. The fish should be packaged in an airtight container, a plastic bag, foil or laminated paper to ensure that the food retains its freshness for as long as possible. The freezer should not be overloaded, and enough space should separate the frozen items to allow cold air to move around them.