The question:

Can a fisher-person catch as many trout in the backcountry streams of the park by using dry flies as he/she can catch using nymphs?

The hypothesis:

More trout can be caught in the backcountry streams of the Smokies on a dry fly than on a nymph.

The argument:

The streams of the Smokies are not fertile. This leaves the trout being opportunistic feeders. They are also not heavily fished. This leaves the trout with little knowledge of mans ways. A big, bushy, dry fly drifting overhead is more likely to be noticed and viewed as an easy meal than a nymph drifting in the currents. Additionally, because the fisherperson can see the dry, he/she can control the drift better making for a more naturalistic presentation. The fisher can also detect the strike more readily, leading to more caught fish.

The counter-argument:

Most of a trouts diet is taken under the surface. Thus, they are more used to taking nymphs than dries, and will hit a nymph more often than a dry.

My view of the counter-argument:

It is certainly true that more of a trouts diet comes from under than the surface than on the surface. However, it does not necessarily translate into a greater catch rate in the backcountry streams of the Smokies due to the factors mentioned in the argument above. In food-rich and slow-moving waters such as tailwaters that are more heavily fished, the argument holds. I will almost always choose a nymph on those streams.

The test:

Spend six hours on a backcountry stream using a dry with a nymph dropper and make an observation about the numbers of fish caught on each.

On Saturday, September 19, 2015, I fished a backcountry stream from 9:00 to 3:00 using an Orvis Holo Humpy (#14 red and #14 lime) with a #16 red Copper John dropper.

The water was particularly low* and the weather was sunny and warm.

* Possible bias: Low water is often conducive to dry fly fishing. During high water periods on this same stream, a nymph may be equally or more productive.

The observation:

I landed 52 trout. A mix of about 1/3 rainbows and 2/3 brooks. 13 (25%) were taken on the nymph and 39 (75%) were taken on the dry.

Discussion:

Some of the trout that took the dry would likely have been caught on the nymph had there not been a dry and vice-versa. This would skew the results. Let's examine that for a moment. If 50% caught on one would have been caught on the other and I was only fishing one fly, I would have landed 45 on the dry and 32 on the nymph. The dry still wins. What would it take to reverse the observation? If 25% of the fish that took the nymph would have been caught on the dry and 75% of those caught on the dry would have been caught on a nymph ... the dry and nymph tie. I believe this an unlikely scenario, so I still conclude that the dry is the winner.

Possible biases:

The low water was already mentioned, but there are more. First off, I have been fishing dries in the park almost exclusively for 20 years. I am more experienced, and better at dry fly fishing than nymphing. Thus, I should have expected to catch more on the dry. I did not attempt to make the presentation of the nymph "best." I fished the dry by placing it where I wanted it to float and concentrating on a good dry fly drift. The nymph was just along for the ride.

The possible bias in favor of the nymph is that I would likely have used a different dry fly instead of the colorful foamy one I used. Had I used a more realistic dry, I would have caught more fish on the dry.

Conclusion:

In summary, there are a few key take-aways from this test. These are very important, so don't miss the point.

First, I had a great day on the water.

Second, there is not near enough data to answer the question of whether or not more fish can be caught on a dry or nymph. I will need to repeat this, and similar tests over the remaining years of my life.

Third, I encourage each of you to perform your own tests and share results with us.