took out a roman this afternoon to defrost for supper.when i took the plastic of it was covered with funny brownish/greenish spots. wife said it looks like frostbite because i didnt seal the bag off properly. i want to know if i can still eat the fish.must i throuw it away.and how must i go from now on to prepare it.dont want to waste the fish because of my own stupidity.any advise greatfully accepted.