I fish barbless most of the time. The only fish that I don't go barbless on are some saltwater species.
If I lose a trout due a thrown hook, it's my fault. Most likely I let the line go slack. Places where I fish for "trophy trout" usually have barbless hooks regs, so I really don't have much say in the matter.
MASH 'EM man. All my trout flies are either barbless hooks or hooks I have mashed the barbs on. I dont lose anymore fish one way or the other, its easier to get the hook out of not only the fish but your hand as well and you will not hurt a fish pulling a barbless hook out. I actually think the hooks, "hooks" the fish better also, you dont have the barb in the way of getting good penatration.
I never did until I started regularly fishing outwest, especially Yellowstone. It was a pain having to worry about whether or not I'd remembered to pinch the barbs on all my flies, and/or sit around one night going through my boxes to make sure. So I just got into the habit of mashing the barbs of everything I was tying.
I do probably miss and lose more fish because my flies aren't barbed, but as MoscaPescador said, 9 times out of ten it's something I did wrong, and keeping fish on barbless hooks is something I'm getting better at.
I don't think it makes that much difference in terms of the sustainability of a fishery compared to other factors (habitat, predation, etc), but it certainly reduces my handling time for each fish, which I see as a benefit. And they're easy to remove from anything else- clothes, skin, fishing vests, etc.
I will echo what everybody has said so far. I fish for trout 100% of the time with barbless or mashed down barbed hooks. I also C&R trout 100% of the time. I am not concerned if a fish gets off the hook because of a mashed barb. If I have one on for a bit and he gets off, well the fight was still fun while it lasted. Plus like others have said barbless hooks are easier to remove from body parts. Once I had a barbed BWO (I hadnít mashed down the barb at home and was going to do it after I tied it on, at the river) go all the way through my lower lip.
I was wetting the knot with my mouth when a gust of wind blew my rod over pulling the BWO out of my hand and through my lip. Needless to say removing the barbed hook from my lower lip on the river sucked and I do not care to ever repeat that experience.
On the other hand on my trip last Sunday I buried a #14 parachute hares ear in my right index finger. This fly had already been de-barbed and I removed it quickly and resumed fishing.
As I told my son as he was pulling the bugger out of his rear..."this is why we mash the barb, its much easier to get out of everything"...and most of the waters I fish require barbless hooks and some of the wardens do the good ole cotton ball test.
I rarely catch a fish that bleeds, but when I do, an examination of the hook
reveals that I failed to mash the barb down completely. I've been tying with
a magnifying lens on my vise for two years, and I check the barbs through
the lens now.
P.S. I read an article by Lefty Kreh, and he mentioned that another famous angler
considered a fish hooked to be a fish caught. When I told my wife that, she
latched onto that philosophy like nothing else...LOL! She does have a tendency to let her
line go slack, and a lot of fish don't make it to the net, but she considers them caught.
Sasha's post reminded me of last summer, when I was recruited to help a fishing partner remove a #24 trico spinner from the corner of his mouth. Basically the same thing happened- he was tying the fly on and it wound up embedded in flesh, and he couldn't see the thing to get it out....
Mash the barbs and don't worry about losing fish. If you play them right you won't lose them. The best time to bend the barb is at the vise, but if you don't tie carry a small pair of smoothed nose pliyers like the Dr Slick De-Barb Pliers. Tiemco also has a simular pair. The pliers with ridges on the nose makes it a lot harder to bend the barb down.
Location: Lake of the Woods/Rainy River Minnesota Canada border
Re: Mashed or not?
In my recent personal experience, I don't think mashing hurts the holding power much. I don't know if you can actually mash 'em enough to make it equal to a barbless. I say this because I did one of the dumber things I have done lately. I was tying a clouser and had the hook point up in the vice. In fact the fly was finished and I was just waiting for the head cement to set. I turned to grab something and sunk the fly all the way to the bend in my right forearm. It picked up my tying station. I tried to pull it out with it still in the vice. No go. I took it out and tried to pull it out with pliers, and still no go. I tried the push down on the hook and pull with a mono loop. Not a bit of help there either. So I jammed it the rest of the way through and mashed the barb. I mashed the snot out of it. Still would not come out. I could not see any of the barb sticking up but it was still sticking like it was glued. How fish ever get off I have no idea. I eventually resigned myself to the idea that the fly was history, and cut the barb and point clean off. Then it backed right out. I don't think the mashed barb works very well. Very well if you want it to come out easy that is. In some places Conservation Officers enforce barbless restrictions with a wool patch. Given the difficulty getting a mashed barb out of my arm I doubt you will pass the wool patch test very easy. If you want barbless, go all out barbless from the start. I would not count on mashing.