Today we continue our series on trout fishing tactics, based on our approach at Chile West but applicable in any water where trout swim! In most trout fisheries nymphs are the biggest part of a trout’s diet, so we’re kicking things off with some information on nymphing.
Current speed is one of the most important things to keep in mind when selecting and fishing a nymph.
Nymphs generally live under rocks near oxygenated water – water with a steady current. In high water conditions, nymphs get pulled from the rocks. When the nymphs are ready to hatch they swim to the surface or crawl out onto land. In both cases, the “heavy water”, meaning faster current, will sweep the nymphs downstream.
Think of the nymphs as silt. The heavier the silt, the faster it settles in the water. As the current speed slows, the nymphs gain the ability to swim to the surface and hatch out or fall to the bottom and crawl under a rock.
With this in mind, it makes sense that the bigger nymphs will hatch in heavier water and the smaller nymphs will hatch in slower water.
There are a variety of nymphs, all with different characteristics and sizes, so let’s simplify things for now and categorize them into two groups – stoneflies and mayflies.
The stonefly nymph will crawl from the river bottom, out of the water, and hatch out on the rocks, so when fishing a stonefly nymph you should concentrate your fishing close to bottom and the water’s edge where the nymphs are more likely to be. Stonefly nymphs come in a variety of sizes, some of them rather large, so think of them as silt – bigger nymphs in heavier water.
The mayfly nymph swims to the surface to emerge. These nymphs range from tiny to small and are more vulnerable to heavy current. The slower the river current, the easier the nymph can swim to the surface to emerge. The faster the current and the deeper the water, the farther downstream the nymphs will emerge on the surface from their lie on the bottom. With this in mind, fish the heavy water with your nymph close to the bottom. As the current slows, fish the nymph higher up in the water column – sometimes just under the surface!