Every few months there is a post in which a poster thinks that barbless hooks will improve or preserve a trout fishery. This was debunked years ago but fly fishers continue to de-barb their hooks in the belief that this saves fish populations.
Barbless hooks minimize scarring and they make hooks easier to remove from clothing, nets, and fishermen BUT they do not improve the fishing; and some barbless hooks actually kill more fish than the barbed variety.
I discussed the science 6 months ago on this post:
Here are the three posts I made:
It is interesting to me that no one has posted research that shows barbless hooks increases fish population; or stated another way, that barbed hooks in a catch and release fishery results in fewer fish. The question is whether the increased mortality of barbed hooks results in fewer fish.
Research show that this is not so.
I think one needs to keep in mind that the goal of C&R is to maintain the fish population at or near the carrying capacity of the river. The assumption is then is that breaking the "barbless rule" somehow leads to a decrease in the population of fish in a healthy river.
That assumption is actually false.
Barbed Hook Restrictions in Catch-and-Release Trout Fisheries: A Social Issue
D. J. SCHILL and R. L. SCARPELLA
Idaho Department of Fish and Game, 1414 East Locust Lane, Nampa, Idaho 83686, USA
—We summarized results of past studies that directly compared hooking mortality of resident (nonanadromous) salmonids caught and released with barbed or barbless hooks. Barbed hooks produced lower hooking mortality in two of four comparisons with flies and in three of five comparisons with lures. Only 1 of 11 comparisons resulted in statistically significant differences in hooking mortality. In that instance, barbless baited hooks caused significantly less mortality than barbed hooks, but experimented design concerns limited the utility of this finding. Mean hooking mortality rates from past lure studies were slightly higher for barbed hooks than barbless ones, but the opposite was true for flies. For flies and lures combined, mean hooking mortality was 4.5% for barbed hooks and 4.2% for barbless hooks. Combination of test statistics from individual studies by gear type via meta-analysis yielded nonsignificant results for barbed versus barbless flies, lures, or flies and lures combined. We conclude that the use of barbed or barbless flies or lures plays no role in subsequent mortality of trout caught and released by anglers. Because natural mortality rates for wild trout in streams commonly range from 30% to 65% annually, a 0.3% mean difference in hooking mortality for the two hook types is irrelevant at the population level, even when fish are subjected to repeated capture. Based on existing mortality studies, there is no biological basis for barbed hook restrictions in artificial fly and lure fisheries for resident trout.
Restricting barbed hooks appears to be a social issue. Managers proposing new special regulations to the angling public should consider the social costs of implementing barbed hook restrictions that produce no demonstrable biological gain.
This research confirms the earlier work (1987) of Robert Behnke, the leading trout researcher in the USA.
Behnke, 1987. Catch and Release Fishing
, A decade of experience. Proceedings from USA National Sport Fishing Symposium.
Summary of Catch and Release based research over previous 10 years for National Sports Fishing Symposium, USA. “consistent agreement among hooking mortality studies that demonstrate no significant difference in mortality of fish caught and released on single, treble, barbed or barbless hooks.”
Professor Behnke wrote an editorial on pg. 56 in the Fall 2007 issue of TU's Trout magazine titled "Trading Stubbornness for Science".
Trout Unlimited is dedicated to the preservation of cold water fisheries. To their credit, they did due diligence and refused to perpetuate the lie that barbless hooks improves the fishery.
To quote Dr. Behnke, ".....statistical analysis of many hooking studies performed over many years agreed that the type of hook was insignificant in determining mortality.
Several state agencies, without an understanding of this scientific data instituted barbless-only restrictions on special regulations waters. When angling violations records were examined in Idaho and Oregon, the barbless violations were the most common. Almost all of these violations were accidental; a fly is broken off and in a moment of excitement, a new fly, not fitting the narrow legal description of barbless, is tied on and the angler commits a violation."
"In view of the fact that there is no scientific or biological justification for the barbless hook regulations, a change in the law in Idaho and Oregon was proposed. Public meeting were held. The hard core, no-kill, barbless-only fanatics generated lots of heat, but no light, in a passionate defense of an irrational opinion."
"I have characterized such irrational behavior by some anglers as a trivial pursuit and the arrogance of ignorance......"
If any requirement of C&R fishing is to adversely impact fish population, it must, either in whole or in part along with other practices, be sufficient to adversely impact the fish populations above the natural mortality level.
It is only then that the trout population will be below the river's carrying capacity.
The are reasons to be gentle on trout that will be released, but let us not forget that what is important is that quality trout are present at the carrying capacity of the river. Sometimes this means harvesting fish, other times releasing fish, and that barbless vs barbed hooks has no effect on fish populations.
There are reasons to go barbless because they cause less scarring of fish, less scarring of fishermen and so on. However to say that barbless make a difference in fish populations or is necessary or even desirable for successful C&R is false.
Lets not perpetuate the myth. If you want to use barbless, great. If you want to use barbed, there is no reason to feel guilty.
Finally, the Wisconsin DNR did it's own research and found that barbless makes no difference in a fishery even when used with bait or lures. The DNR removed all barbless requirements in our special regulations fisheries. When presented with the research, I voted as a member of the Wisconsin State Council of TU to support that change.
I would also add that an occasional photo does not make a difference either. If you do it fast, gently, and resuscitate before release, you are not harming the fish population.
Other than harvesting fish, in my view the greatest harm is done by anglers that overplay fish.
I wanted to chime in again on the barbless hooks since almost all fly fishers are unaware that the science on larger barbless hooks has changed by 180 degrees.
The main reason is the stiletto effect
of barbless hooks. With no barb to hold the hook in place, the barbless hook becomes a curved blade or knife that can make multiple stab wounds as the fish struggles. With no barb, the hook can penetrate deeper reaching the carotid artery or the brain of the trout.
See this quote on page 76 from About Trout, The Best of Robert J. Behnke from Trout Magazine. Professor Robert J. Behnke
is the leading authority on trout and Trout Magazine is the publication of Trout Unlimited.
"Almost all hooking mortality studies have demonstrated no significant difference in mortality between trout caught on single ...... barbed, or barbless hooks. There is however a slight but consistent increase in mortality due to barbless hooks.
...... this is due to what he calls the "stiletto effect" ....... almost all mortality of trout caught on artificial lures or flies is due to rupture of the respiratory filaments of the gills or penetration of the carotid artery in the roof of the mouth. Because of their greater penetration power, barbless hooks are more prone to puncture the carotid artery."
Here's another quote from Fly Fishing Yellowstone
: "There is no biological reason to believe that a barbless hook is going to increase the chances of a trout's survival. There is a public perception that it does. So; as noted previously, here, Yellowstone National Park has changed it's fishing regulations to require barbless hooks. -- As soon as the stiletto effect, (and it's deep infections,) becomes widely publicized; fly fishers, the public, and the powers at Yellowstone National Park will probably change the rules again."
There has been a patent awarded for a barbless hook that reduces the stiletto effect. Here's a quote from the patent application, "To date barbless hooks have been made from normal barbed hooks flattening the barb out. Without the barb these hooks cause less damage to the fish upon removal, however they can cause severe damage to the fish during the fight as they tend to jump around a fish's mouth, making several wounds as the hook jumps out and repositions elsewhere. This is known as the "stiletto effect"........ The bulb just behind the point of the hook provides some holding power thereby reducing the "stiletto effect" while increasing the chances of landing the fish, and allowing for fast and safe release causing less damage to the fish and increasing its chance of survival."
The bottom line is that barbless hooks can kill slightly more fish
than barbed hooks. I still believe that small barbless hooks kill slightly few fish than barbed hooks but larger barbless hooks actually kill more fish than barbed hooks. Larger barbless hooks can "brain" trout; and by repeated punctures, even smaller hooks have a greater change of a fatal carotid artery or gill injury.
There are reasons for and against both barbed and barbless hooks. You will land more fish with barbed hooks. Barbed hooks take a bit more longer to remove and cause more local soft tissue scaring of fish. Barbless hooks are more easily removed if you hook yourself or someone else.
Personally I pinch down the barbs only when required by a barbless hook regulation, or when using really small hooks (18 and smaller) that are difficult to remove anyway. I never pinch down the barbs on streamers or hooks larger than 16 unless required by law. Barbless hook regulations are contrary to the latest research and may make us feel good while they are actually killing the fish they were meant to preserve.
By de-barbing the larger hooks and not the smaller, you are actually doing just the opposite of what science tells you to do to save the most fish.
It is point of the hook kills and not the barb. The function of the barb is to hold the hook in place, and the function of the point is to stab and penetrate. It is the act of stabbing that kills fish.
Ouitdoors in Maine: Barbless hooks revisted | Sun Journal
Barbless hooks have been sold to fly fishers on the basis of less mortality with the belief that the mortality difference would lead to more fish.
But the science has shown that there is only a slight mortality difference between barbed and barbless hooks. This slight difference has ZERO population effect. It is the act of catching a fish that is the overwhelming cause of C&R mortality and not the type of hook used.
The "advantage" of barbless is when we hook our nets, clothing, or ourselves. I believe this should be the choice of the fly fisher and not legislated.
There is also a cosmetic advantage in that there is less scarring of the fish. Barbless may be an esthetic issue, but it is not a population issue in my opinion.
In my state of Wisconsin we used to have a mandatory barbless hook regulation for an early season fishery. This was repealed when our DNR's own research and the studies of other researchers became known. We now have an early season without a mandatory barbless hook regulation.
There is the issue of the stiletto effect. I happen to believe that it is real and that it does cause more injury. I also believe the injury potential increases as hook size and potential penetration depth increases. So I individualize when I will remove my hook barbs and when I will not.