Protecting A Fishery With Ineffective Angling?

February 2025

We know modern tactics are improving catch rates with new techniques like jigged nymphing, and new technologies, like forward facing sonar which is lighting up the scene in the conventional tackle world.

We also know that fish need recovery after angler encounters. Plus, too many angler encounters can change fish behavior to the detriment of catching the same fish in the short-term future. Multiply all that by every angler on the water spooking, or hooking fish and this is how you end up with "educated" fish and technical waters... So, logically, it would follow that if anglers were less effective, any potential impacts from hook-to-fish entanglements would be reduced. Fishing pressure, in some ways, could lighten. Further, over time bold behavior in fish (willingness to chase flies) may bounce back too. All of this is a long way around to say this: maybe we can choose to fish ineffectively on purpose to support the whole of the fishery. It's an angler-behavior conservation strategy I haven't seen discussed as viable regulation in the trout fishing world, at least not using this argument. But it does have roots in salmon angling.

We can explain the argument with some simple math. If you think of your next catch as a probability, it would be based on factors like overall fish density, water conditions, effectiveness of a fly and angler prowess. From there we end up with a probability value for catching any given fish: how many times out of 100 tries would that fish eat your fly in that situation. Usually anglers try to maximize things like fly effectiveness, or strive for maximum angler prowess to increase their odds. But instead, if anglers actively suppress these characteristics they could reduce their individual impact on a greater number of fish over the course of their fishing excursion. (See Appendix). Catching less, intentionally.

How would that look in practice?

Maybe you only skate dry flies, passing over nymphing all together. Maybe you only fish certain larger patterns in hopes of drawing out the rare large fish, knowing you're sacrificing opportunities for catching numbers. Streamer junkies might already be using this approach, though I can't say their motives are necessarily derived from conservation goals. Maybe you just swing flies. These tactic restrictions are actually in place on select world famous Atlantic Salmon fisheries where fly fishing is the only permitted method, and single unweighted barbless flies with no more than two hooks are allowed. They also enlist a pool rotation to keep anglers from working the same piece of water for too long. Undoubtedly there are more efficient ways to catch fish, but that's not really the point of the rules.

It's something to think about when fishing your home waters, or chasing native fish in pristine places. Maybe it's worth trying when summer temperatures start climbing and fish are on the brink of over-stressing even before factoring in angling pressure.

Sources:

• New Fly Fisher. 2020. Atlantic Salmon Fishing Basics. https://youtu.be/amUEmRL7oYc?si=xDHjeAJpGDFcD43o&t=912
• Shostak. 2021. Drake Equation. SETI Institute. https://www.seti.org/drake-equation-index

Appendix:

Catch Probability =D⋅F⋅T⋅W⋅H⋅A⋅Y⋅S⋅Ti

C = Probability of a Catch

D = Fish Density

F = Fraction of Feeding Fish

T = Fraction of Fish in Favorable Temperature

W = Fraction of Fish in Favorable Water Chemistry

H = Fraction of Fish in Suitable Habitat Patch

A = Fraction of Fish Near Abundant Food Source

Y = Effectiveness of Fly

S = Angler Skill

Ti = Time spent by angler