Stoneflies can produce some fantastic nymph fishing, especially in the cold flows associated with the spring months. These big tantalizing insects are prolific in most cold, clean streams found throughout the greater U.S. making them a staple in the diets of large trout. For most inexperienced fly anglers using a tiny nymph pattern does not seem like it could strike up interest from trophy class fish; but in all actuality out of all the lunkers caught every year a large majority of these fish are taken by nymph patterns.
Foragers: Stonefly nymphs live on the river or stream bottom, crawling on and around sticks and rocks to get food.
Stonefly nymphs live on the river or stream bottom, crawling on and around sticks and rocks to get food and take shelter from their many predators. As a group in general, stoneflies require well-oxygenated, high quality water, making their prime habitat fast, riffled stretches of pristine river.
Residing on a half-sunken stick or submerged tree branch is one of the stoneflies nymphs' favorite hiding spots, but these types of structures are not always the safest places for these aquatic critters. Being washed free from their cover or being caught in the current isn't unusual for stoneflies nymphs, making them very vulnerable to hungry fish.
During the normal course of their underwater life, stonefly nymphs have to avoid many potential downfalls but the danger from hungry fish is especially heightened in the spring when the mature nymphs migrate towards shore to molt and become an adult. If a nymph is able to reach the shore it will climb out on the surrounding rocks, grass, or tree branches, and emerges into an adult. Fortunately for fish many nymphs are not so lucky. They are knocked loose and drift helplessly to the hungry fish waiting below. As the migration of stonefly nymphs heightens, trout key in on this very quickly and wait along the edges of the shallows to feed on these tasty morels trying to escape to the banks of the river.
The necessary fly tackle for stonefly nymph fishing is not any different then traditional fly tackle:
5- or 6-weight fly rods matched to the proper weight fly reel
Forward-floating fly line
Light tippet material (2x to 4x)
Standard 9-foot leader
In nature when a stonefly nymph becomes dislodged from a stick, the nymphs tumble across the bottom out of control. Very rarely do these aquatic insects allow themselves to be found higher in the water column seeing as this would put them in grave danger. Therefore as educated fly anglers presenting your flies on or near bottom is a must to get a consistent bite from fish.
Getting your fly down to the bottom of the river as fast as possible can be accomplished in a few different ways. The best technique to allow your fly to sink fast is to heavily-weight the fly you intend on fishing and using a light 2X or 3X tippet. The combination of a weighted fly and a light tippet will allow the fly to sink fast by not having excessive water tension working on the tippet. A forward-floating line and some sort of a strike indicator is a good addition to this system seeing as this will allow the angler the best opportunity to present the fly to the target and see takes from fish.
As with any other heavily-weighted flies; long casts need to be avoided. Short upstream pitches are ideal and should be used whenever possible. Casts in the 15-25 feet range are what you are looking for and make it easy to handle to fly and detect strikes from fish. Once the fly has hit the water let the fly sink and indicator drift downstream. Fish the indicator as you would a dry fly, making mends to the line as needed to achieve a drag-free drift.
The sunken fly should be on or near bottom bouncing all the way down stream. As the fly drifts downstream past your position; gather the slack line to keep the fly drifting as natural as possible. Once the fly starts to swing beneath your position pick the rod tip up slowly to see if any fish are flowing quietly and then proceed to start your next cast. Make sure to keep up with the slack line being created as the fly drifts, you will get a better drift with less slack and you will be able to strike more quickly when a fish bites.
Ready, Set. To set the hook, simply raise the rod and pull the fly line down with your free hand to take up the slack and bury the hook into the fish's jaws.
Even though stoneflies nymphs can be found throughout all the different water types found in a stream, fishing these flies in three specific types of water can be especially productive.
- Current seams: This type of water condition can be defined as any place where fast-flowing water currents join up with slow flowing currents. Currents seams can be found thought large runs or near sunken logs, just take a few seconds to observe the water you intend to fish before you let your nymph fly. Cast your nymph just above the seam and allow the fly to drift along with the slow water next to the fast current. Fish will find this presentation deadly, and will strike greedily to swallow your fly.
- Slow, deep pools just downstream from a fast glide or shallow riffle: Pools that form at the bottom of glides or runs are great for holding hungry fish. Fish will stage in these pools waiting for aquatic insects to be flushed downstream into their mouths. These pools are ideal for fish who want to feed heavily while expending little or no energy in the process. To fish these runs, simply cast the fly in the run and allow the fly to drift naturally downstream into the slow-moving pool.
- Fast riffled rock runs: Boulder fields and areas that hold large rocks are great spaces for trout to hide and ambush unlucky stoneflies that have been washed loose. These large rocks provide the much needed current breaks for fish to sit, requiring little energy to fight the fast moving current. Additionally this faster-paced water will jar free lots of aquatic insects for the fish to feed upon. Target the slow water areas located behind the rocks for your fly to drift through. In this slack water the fish will magically appear and take your nymphs swiftly.
For these three different sections of river ideally it is best to do your fishing at the downstream end of the stretch of water. Cover the water just above you thoroughly, and then proceed to move upstream. If you were to cast directly to the head of the hole then you could potentially end up scaring any fish at the bottom of the stretch of river with your fly line.
If you decide to go out and do a little stone nymph fishing then understanding how to read your strike indicator is a must. First and foremost, do not set the hook if you see a slight bit of movement in the indicator. If your fly is bouncing the bottom like it is suppose to then the strike indicator will constantly be stopping and jerking as it works it way down stream. When trout take stonefly nymphs they usually do it with gusto, so you should not have any problem identifying the strikes from the fly bouncing on the bottom. To set the hook, simply raise the rod and pull the fly line down with your free hand to take up the slack and bury the hook into the fish's jaws.
Types of Fly Patterns
If you walk into any fly shop around the world you will find dozens of different styles and colors of stonefly patterns that imitate these aquatic insects very well. Truthfully the patterns that do not look like exact replicas of insect seem to work best, but a few key features will help your patterns stand out from the rest. Ideally the pattern you choose to fish with should be heavily weighted in the underbody to get the fly down to the bottom fast, but the incorporation of a bead to the head of the fly will add weight along with some flash. Along with this flies that have rubber legs used in their construction will add much need movement in the water. Another good idea is to try and find a pattern that uses some sort of vinyl or rubber ribbing for the body, because this stiff, sturdy material will help with the fly's durability.
The stonefly nymphs you choose should match to the color of the insects living in the river you will be fishing. If you are not sure about the natural stoneflies colors carrying patterns in either black or chocolate brown should cover most conditions. The size of the fly pattern is another concern for anglers. Basically the earlier in the season the bigger the stonefly nymphs will be. Carrying a few different sizes is a good idea, and when you hit the water turn over a few logs to see what size fly best matches the resident stones.
If you are looking for an edge this coming season or simply a change from the norm then using stoneflies to target large aggressively-feeding fish could be exactly what you are looking for. Early season stoneflies can be much different than anything you have ever fished before simply because of their hefty size, and it is this size that is ever so enticing to fish. Work the flies thoroughly though holes and rifles, but be warned; hold on tight it won't take long for fish to get excited and into a feeding frenzy over the stones you are serving up.