Norm -- there have been scads and scads of research projects on hooking mortality that compared barbed vs. barbless hooks. Maybe I can make two overview comments.
1. I would contend that we can see no decrease in hooking mortality from barbless hooks. I know, I know: this does not fit with "common sense," and some folks will want to throw rocks at me! However, I can show you just as many studies where barbless hooks had the same or more mortality as did the barbed hooks. It sort of splits out on a 50:50 basis. The Trout Unlimited anglers don't like to hear this, but it's true. We just don't have evidence that barbless hooks reduce hooking mortality, even though common sense says they will be handled less and should have higher survival.
2. There have been a couple more recent studies actually showing that barbless hooks can cause MORE mortality than barbed hooks. One study was on bluegills in Nebraska, and another was on largmeouth bass. So, HOW CAN THIS BE? Well, the contention in those two studies was that the barbless hooks would actually penetrate further, and a greater portion of fish hooked in the roof of the mouth would have the hooks penetrate the brain case.
So, we'll see what kind of hornets nest this might create. However, that's my story and I'm stocking to it! :-)
Dave
