Yeah, Rapala put out a great book 30 years ago on how to properly freeze and preserve fish. Key: Don’t wash the fish until you thaw it to use. Water on filets immediately starts bacterial breakdown. We usually try to eat it within a month. Fatty fish like Lake Trout and Salmon you don’t want to go much past that. I have some invalid friends I share with as well. They can’t fish, and can’t really afford to buy much fresh fish.