Nymphing with ice-movement.
In our area, there is always a chance of frozen rivers and anchor ice in the depths of winter. When that occurs and the thaw begins allowing the ice-dams to break or the anchor ice to move, large nymphs can be dislodged and become vulnerable to trout. So even in the depths of winter is it possible to catch times when there are a number of nymphs tumbling in the water having been dislodged by the moving ice.
Nymphing During Run-off
As note above, during run-off the nymphs tend to get dislodged by the increased water flow and debris . During that time the water tends to become a little discolored emboldening the trout to seek the nymphs in the shallower opaque stretches. If the run-off is strong and dirty, the trout will seek the more protected areas the dirty water will fill the trout's gills with silt. Consequently the trout will seek the slower moving water where the current will not hold as many silt particles. Again, the relatively opaque water will provide protection to the fish not afforded when the water is clear.
The most productive method for fishing a stonefly nymph is the dead-drift presentation accompanied by much line mending . Having both weighted and unweighted patterns is advisable. Some patterns are tied on curved hooks to imitate a nymph's appearance when it is tumbling with the current. While trout will take both the standard version or the curved type, having both styles is a good idea.
The stonefly nymph can be drifted down and across stream into holes, alongside logs, or through undercut banks where large trout are likely to rest. Occasionally, try some pulsing action, especially at the end of the drift.
Try to feel the fly bouncing on the bottom and watch for hesitation in the line drift. Often a rock or stick will cause the line to hesitate, but sometimes it will be a fish. Set the hook anytime the line stops moving.
Adding weight to the line might make the rig a little unwieldy so one may be forced to rely on the "lob" cast. This is a short line variation of the roll cast. Essentially one allows the line to drift downstream to the full extent of the line and leader. This will bring the fly to the surface and impart tension to the line. As the pressure on the rod increases, pick up the line and roll it up stream to the desired position. The key is to allow the drifting line to extend itself fully to impart maximum pressure to the tip of the rod when the cast is about to be made.
When short-line nymphing this way, it is paramount for the fly to be on the bottom of the river. If you do not feel your fly bouncing along the bottom every other cast or so, add a little more weight. The type of weight one uses is open to debate. Split shot will weaken the line when attached. On the other hand, mouldable putty is fine in theory but in summer it runs like honey and in winter hardens without fastening itself to the line. Twist-on lead strips are also useful, but as they have to be crimpled they can also weaken the line. My preference is to use say 3x tippet then attach several pieces of tippet down to 6x or 7x. The shot or lead can then be attached on say a short 4x or 5x section and the knots will prevent the twisted lead slipping too far. However, in dirty water where material can be picked up by the knots and the weight, one will be cleaning the line often.
Leaders can be relatively short - from six to 10 feet long tapered and heavier than you normally fish if water conditions are particularly murky.
Always keep your hooks sharp as bouncing stoneflies along rock covered river bottom dulls the hooks quickly.
Even when there is no major stonefly activity on the river, stoneflies are always excellent patterns to use during times when no other obvious feeding activity is going on.
During low flows of the late season, drifting a stone through deep runs will often produce trout when all other fly patterns fail to interest. It is always good to try a dropper with a smaller fly trailing the larger stonefly.
Fishing During Emergence
As previously noted, nymphs crawl ashore onto rocks near the banks to shed their ekoskeleton. They use the sunlight to dry off their wings, then climb in the bushes surrounding the stream to mate before flying onto the water to lay eggs. Consequently, fishermen should look for fish hanging out under streamside bushes, waiting for big stone flies that are either crawling ashore or that have fallen into the water after drying off. Undercut banks, logs and other structures will hold fish waiting for the fallen stone to crawl or drift by. Look for areas where the growth is tight to the bank.
Dry stonefly imitations can be fished much like hoppers. Fish them upstream with a “splat” next to a log or undercut bank. Presentations need not be delicate. The stonefly females very often land on the water with a small splash and to fish the stonefly hatch one should do the same. Aim the fly a little low so that when the fly lands on the water it splats down.
Imparting action to the fly on the water is an important ingredient in imitating a struggling insect.
If there is no immediate strike, allow the fly to drift drag-free downstream a bit and then make it skitter and dance a bit on the surface. High-sticking will help. A longer rod will also assist. The stoneflies move about actively on the surface and this can attract a trout's attention as well. Because the stoneflies move and dance about so much on the water the trout slash and swipe at them. Consequently, strikes are often violent.