Re: Hook wire diameter; relation to fish injury
Wannafish, I have not heard that, but IMO it would depend on the specific hook, the species being hooked, where in it's anatomy it may be hooked & the situation of landing the fish. Prolonged fights with lighter than practical equipment too could cause more damage regardless of the wire diameter. There are many variables that might cause an issue.
Generally, I think most will agree that lighter wire hooks, properly sharp will penetrate easier & quicker than a similar hook of heavier wire. Also, barbless hooks will usually penetrate easier & quicker than a similar size barbed hook even when the wire diameter is the same. This is a matter of larger cross sectional area as the barb penetrates. However additional damage can occur with any hook depending on the length of time it takes to subdue the fish & of course improper handling can compound the possible damage while attempting to remove a hook.
Too many variables to simply say that wire diameter is cause for concern as long as the hook sizes & style being used are reasonable IMO.
It's admirable that folks are concerned for the fish, as well as they should be if they intend to practice catch & release. Even in situations where the fish will be kept & consumed, there should still be some concern as not all fish that may be hooked will be "keepers". However, there's going to be some degree of damage as the hook penetrates & there may be some mortality no matter how careful an angler might be.
With all that said, the fact is that fishing of any type is a blood sport, even fly fishing. The only sure way to prevent damage to the fish is to not fish at all.
For myself, that's not an option! It's a choice we make.