C&R salmon fishing is wrong in the river where they have a low chance of survival after being released. C&R should only be done if you caught a fish you are not targetting and you don't want it or you cant legally keep it. In the chuck they can rest up, so not much an issue. But in the river as they embark on that epic return for their one and only chance to reproduce? Give me a break! Go to a stocked lake and fill your boats if you still want to C&R.
When you get your limit river fishing salmon (either sockeye, coho, chum, Chinook), go home. Especially sockeye!!!
Never never go just to simply C&R. As I said, take up trout fly fishing if you want to do C&R. That's what I do.
I'm guessing this is simply bait from the trolls under the bridge but I will bite anyway in case it truly is a misguided angler.
While studies continue on mortality rates of C&R, and nothing has been concrete either way, I can only go on 30+ years of fishing experience as well as my background in conservation.
Salmon, like any other fish in the river, have plenty of places to hole up and rest. They are not on some continuous march up the river. They will often pull into areas of slack water or in the eddy of large rocks and debris to rest before moving on.
From the thousands of fish I have seen in my line of work at the final spawning grounds sitting on their redds with huge chunks of flesh missing from bears and eagles, treble hooks and lines sunk deep in their back, and massive amounts of line and ripped up net tangled around their fins, it's my opinion that salmon are a lot more resilient to C&R then you are giving them credit.
I highly doubt a minute or two fight with a fish which is carefully released will cause so much stress that they will be unable to continue their journey upstream.