I did a lake trout study on walker lake, northwest of Bettles,  in the late 80s. Big lake. Mark and recapture.  Few fish lost. It was amazing that for the size of the lake how few fish there were. Many a yard long but about the size of your arm in diameter.  There were arctic char there too that were like 8 pound bulldozers. Invertebrate diet. Short growing season.  Like most of northern alaska, or alaska in general cannot support a modern human harvest. Not enough energy input. Simple math. I imagine some of the 3 plus foot fish we tagged were very old.