The following is not a figment of my imagination, but comes from real-life experience and multiple interviews with Washington State Fisheries biologists.
More than a decade ago the Pend Oreille River had become a world-class Northern Pike Fishery. Some traveled thousands of miles for a chance at the plentiful lunken pike. The local economy was enjoying the prosperity that comes with the deep pockets of passionate fishermen. Fishery management complicit with tribes decided to destroy that fishery.
Subsequent to that debacle the same group took their landing craft-size boats loaded with gillnets into Lake Roosevelt to pursue the few pike who had managed to escape. They placed their nets far and wide in Lake Roosevelt. They caught some pike but the collateral damage to other species was and is unconscionable.
Unfortunately, the walleye bore the brunt of this misguided attempt at fishery management. A brood-sized walleye caught in a four-inch gillnet had about a four-hour window before it’s too late.
Walleye and northern pike are both excellent table fare and a capable person can debone either.
As far as farm-raised trout or salmon are concerned, I would suggest you research the chemical composition of the pellets they are feeding on.