You are correct, the statistics are for reproducing populations.
However, for non reproducing populations
the difference is mortality is still less than 1% or less than 1 fish in 100 caught and released.
What kills the majority of fish is not whether the hook is barbed or not, but how long the fish is "played" and how long it is out of the water during the release.
While you can argue that barbless hooks in non reproducing populations are a benefit, I would argue that it is not worth the time for a game warden to check whether a fly has a barb or not. This comes from the experience with a barbless fly only regulation in my state of Wisconsin.
My state had a barbless fly only regulation in place for out early season C&R only fishery. The DNR wardens found several problems with enforcing the regulation.
A major problem was how to determine whether a hook was "barbless" or not. The DNR used a "cotton ball" test. For anglers who had crimped the barb on fly, they pushed the hook point into a cotton ball and if the hook came out with ANY cotton filaments on the fly, the fly was deemed to be barbed. This meant that anglers who had crimped the down barbs on their flies but the fly still captures a filament of cotton were cited. So anglers who were crimping flies, but failed the test were fined.
These anglers were a majority of the barbless infractions.
Secondly, wardens who were checking anglers for barbless hooks had less time to check anglers for licenses and keeping fish.
So citations for those more serious offenses went down.
The very next year, the DNR asked the Wisconsin Conservation Congress to remove the barbless fly regulation for the Wisconsin Early Season. They asked the Wisconsin State Council of TU Chapters to support removal of the barbless regulation and as the State Council Representative I was at that meeting and listened to the DNR reason for asking for repeal of the barbless regulations.
Up to that point both Wisconsin TU and FFF had supported the barbless fly regulation. We reversed our position and supported the Wisconsin DNR in repealing the barbless regulation.
What I learned is "good intentions" do not always translate into good regulations. Every new regulation places a burden on game wardens and my current view is that
any new regulation must show a benefit that is greater than it's regulatory cost on the fisheries personnel.
Here is a more detailed explanation from a previous post:
Our own University of Wisconsin conducted a study that confirmed that barbless regulations are
not needed, and in fact, are a waste of Fish and Game warden's time and resources. They also foster ill will amongst the fishing public. The most frequent ticketed violation in our barbless fisheries was the use of a barbed hook. Most of these violation were inadvertent, when either a barbless fly was lost and a new barbed fly was used or when the barb was not pinched down sufficiently.
From the UW study:
"Managers of stream trout fisheries must often make regulatory decisions based on incomplete or contradictory information, and if these regulations do not produce the anticipated biological advantages, agency credibility can suffer. Unnecessary regulations that restrict angling opportunities without producing biological gains can be particularly damaging, especially in the current national situation of stagnant or declining license sales in most states."
Several years ago, the Wisconsin DNR proposed that barbless flies only regulation be removed from our early trout season regulation. Modern fisheries research has shown that barbless hooks do
not result in improving the number of catchable fish.
At the Wisconsin TU State Council meeting, we supported the Wisconsin DNR proposal to remove the barbless regulation.
Regulation changes in my state go before a public vote of all sportsmen called the Wisconsin Conservation Congress. Here is the actual DNR ballot that was submitted to a statewide referendum of sportsmen at the Wisconsin State Conservation Congress.
"QUESTION 6 ? Eliminate barbless hooks restriction during early trout season.
Numerous scientific studies have been conducted showing that the use of barbed versus barbless hooks has little effect on trout mortality following release. In a 1997 study published in the North American Journal of Fisheries Management, for flies and lures combined, the average hook related mortality was 4.5% for barbed hooks and 4.2% for barbless hooks. Because natural mortality for wild trout range from 30-65% annually, the 0.3% difference in the two hook types is irrelevant at the population level, even when fish are subjected to repeated catch and release.
Most biologists agree that how deeply a fish is hooked has more to do with mortality than what type of hook is used. Despite the scientific evidence, anglers are required to use barbless hooks only during the early catch-and-release trout season. Elimination of that restriction would simplify trout fishing regulations and eliminate law enforcement issues.
The use of live bait will still be prohibited during the early catch-and-release trout fishing season. If adopted, this proposal will take effect on the first day of the month following publication in the Wisconsin Administrative Register.
Do you support allowing the use of barbed hooks during the early catch-and-release trout season in Wisconsin?
6. YES_______ NO_______"
The measure passed because if you educate sportsmen they can make the right choice.
Notice that the Wisconsin DNR specifically referred to the finding of the Scarpella and Schill study as the reason to make this change. Their study is the current gold standard comparing barbed and barbless hooks for fish mortality.
Fly fishers need to realize that we have little control over where the fish is hooked.
What we can control is the use of heavy enough tackle to quickly bring the fish to the net and removing the hook why the fish is in the water. This will save more fish than barbless hooks ever can.
