There's some discussion on the course angling scene (who are always ahead of us game anglers) that barbless hooks cause more damage due to the amount of additional movement. To be honest i've never really been overly sensitive to the barbless only regime let's face it what effect does a micro barb have really? We should be more worried about poor handling of the fish after hooking (and i don't jut mean after landing either, an over-extended 'fight' can be seriously dangerous to the fish).
Having said all that, and been present with scientist guys for scale sampling, electro tagging and electro fishing, even simply watching fish in their general annual spawning regime i've witnessed the fact they can stand up to quite a bit of 'punishment' with no serious after effects. Be careful of the 'moral' stance as well, 100% C&R does not give you the 'High Ground' selective retention of fish does, that way you are 'harvesting' and being very selective on a food source, not merely using another living animal for self gratification. But all wild troots over two pounds should be carefully returned
