Not that this has anything to do with science its just an observation. The last three years we have had some pretty good numbers of salmon make it over lower Granite dam. We have caught several with net marks on them. I doubt that these fish were released by the commercials or tribes, they got away on their own some how. One fish we caught last year had a 3 inch deep cut in its belly just behind the anal fin, and two more marks up further on the body.