Interesting question. Right now on the South Fork of the Snake River the Idaho Fish & Game has lifted all limits on rainbow trout and are encouraging anglers to harvest any and all rainbow trout they catch. They are even offering cash rewards for some selective-tagged fish. The competition between the rainbows and the native cutthroat is supposedly forcing the cutts out of their native range, thus the encouragement to kill the non-native bows. Browns are also not native to any watershed in the state. As for me, it would be a sad thing to harvest all of the brown trout out of my favorite spring creek just because they are non-native and thus considered 'invasive', since there seems to be approx. 90% browns, 9% cutts and 1%or less of bows. I think C&R makes sense in most cases and for most species. Every now and then I harvest a rainbow from the South Fork, but for the most part I continue to enjoy the sport the so-called 'invasive' species adds to the diversity. Last year I caught a South Fork Slam by hooking and landing a native cutthroat, a rainbow, a brown, a cutt-bow hybrid and a whitefish all in the same outing. I call that good sport and a very successful day (if I were to consider only native species as a slam then I could have stopped at the cutthroat and the whitefish...). Most, if not all of the rainbow and brown trout in the South Fork are native bred and born, not planted.
Current regulations on the Henry's Fork - both upper and lower -, in those areas that allow catch-and-keep, do mention that no cutthroat trout may be kept, which would lead one to believe that they are striving to re-establish the cutthroat population in that river. The upper river on the most famous stretches of the Box Canyon and the Railroad Ranch, are most famous for the tremendous rainbow trout fishing - no other species really is established in those upper reaches of the river - yet the rainbows are not native, and current regs nevertheless require zero harvest and flyfishing only on those stretches of river.
We all have to decide on our own what we consider 'invasives' and whether or not they add to or detract from the sport. I don't have a good answer, just what I've experienced and practiced. I'm sure there are some real problems in some waters with species that compete with the natives, but when it comes to trout I consider them all sport fish and appreciate the diversity. Real invasives to me are those such as snails, mussels, and rock snot; I think they pose a far bigger threat to our sport than do competing species of fish. I also don't advocate planting your favorite waters (bucket biology) with some species you think you would prefer live there. A few years ago someone or someones did this in Yellowstone Lake with Lake Trout and now they are eating the native cutthroat out of house and home - current regs require mandatory killing of any Lake Trout caught.
For me, C&R extends to all of the fish I catch, with very, very few exceptions.
Kelly.
Tight Lines,
Kelly.
"There will be days when the fishing is better than one's most optimistic forecast, others when it is far worse. Either is a gain over just staying home."
Roderick Haig-Brown, "Fisherman's Spring"