And oh my! Those purist fly fishermen probalby kill more than all the rest (excluding the indians) ever watched a fly fisherman hook a big Steelhead only to play it out for an hour or more? That fish has little chance of survival.
If you want to protect the natives, close it all down and leave them alone in the river to do their duty. Maybe some day there will be enough come back that a few dead ones from whatever means of death, will not hurt the system.