May 23, 2016
Learn the dominant hatches in lakes, ponds, and reservoirs, and how to imitate them
Thousands upon thousands of lakes—from tiny alpine tarns to large, lowland irrigation impoundments—dot the geography of the Western United States and Canada. Many of these water bodies are incredibly rich ecosystems that support self-sustaining or augmented trout and char populations.
These waters support diverse fishing opportunities, from lots of small fish to quality, managed fisheries that regularly produce fish in excess of 10 pounds.
Each year more and more anglers are discovering the challenges and rewards of fly fishing in stillwaters. While there is a mind-shift in thinking standing versus moving water, the basic fishing instinct and level of angling success in either venue is gauged by our understanding of where the trout live and how they interact with their primary food sources. An added bonus is that many of the most significant trout foods are aquatic insects that are common to both stream and stillwater environments.
Trout have simple lifestyles once we look beyond the basics of adequate water quality. They need access to productive feeding zones, as well as nearby resting areas where they are safe from predators.
In lakes, the most abundant sources live in the shallow water or shoal zones of the lake. This equates to water less than about 25 feet in depth.
Within this depth range, sunlight energy can penetrate to the lake bottom and allow photosynthesis to work its magic. Submergent and emergent green plant growth thrives under the influence of a long, sunny growing season. Underwater forests of pondweed, coontail, milfoil, bulrush, cattail, and chara provide ideal habitat for important invertebrate trout food sources. They include scuds, midges or chironomids, mayflies, damselflies, dragonflies, caddisflies, leeches, water boatmen, and backswimmers.
The transition zone between the shoal and deep water is known as the drop-off. Plant life becomes less abundant as the water gets deeper because the influence of photosynthesis becomes less pronounced. Drop-offs are important refuge areas for trout, particularly during warm summer periods when the shoal water can be too warm for the trout during daylight hours.
The deepwater zone of the lake is often referred to as the abyss, as it is the deepest part of the lake. The maximum depth of many small trout lakes is often less than 50 feet, but they can be much deeper. The deep water is home to tiny crustaceans such as zooplankton, which at times are an important part of the diet of all age classes of trout and in particular of juvenile fish.
At other times of the year, the deepwater zone yields significant chironomid emergences, bugs coming off in 65 feet of water and trout gorging on the pupae right at the lake bottom. That scenario does provide some very interesting fishing opportunities.
In the fall, water boatmen and backswimmers undertake mating and swarming flights, which often sees them diving into the deep water of the lake. Trout sense their presence and take advantage of this abundant food source in water that is less traveled.
The most prolific and well-known North American stillwater fisheries are blessed with the right combination of water chemistry, a good balance of shoal and deeper water areas, a diverse food base, and a long growing season. Add some progressive fisheries management objectives and regulations, and you create another fly-fishing paradise.
Fishing from a Boat
All the fishing tactics discussed in this article are based on presentations from an anchored craft. If possible, your boat should be anchored from both the bow and stern so that changing wind directions will not move the fishing platform. This setup allows you to maintain control over retrieves, which is critical to detecting strikes regardless of line type or retrieve.
A depth sounder/fish finder is another key piece of equipment. They allow you to see the shoals, sunken islands, drop-offs, old stream or river channels and they tell you the depth you are fishing.
Sounders with side-scan capabilities are ideal since so much of the best fishing occurs in shallow water. Having the ability to scan fish to the side or in front of the boat confirms that you are fishing over productive water. The bottom line is that proper depth presentation and fishing location are as important as having the right fly.
The most prolonged and abundant aquatic insect emergences in Western stillwaters are chironomids or midges. They are always the first hatch of the year, and often also the last hatch of the year just prior to winter and ice cover. There literally could be several hundred species of chironomids inhabiting any given trout lake. Trout of all sizes will feed on the larval, pupal, and adult stages of the chironomid, but it is the pupa that fish literally gorge on day after day for weeks on end during the spring through mid-summer period and then intermittently right up until winter sets in. Big trout love to eat small food items when they are in abundance.
"Small" is a relative term when it comes to describing the size range of chironomids found in productive Western stillwaters. Pupal patterns are tied in hook sizes ranging from almost minute #20 to big bombers on #10-3XL. A heavy chironomid emergence could easily see literally hundreds of thousands of the pupae in one small area of a lake making their way to the surface to complete the transformation to the adult phase. Trout simply swim through the water inhaling pupa after pupa with each breath they take. The key to being consistently successful during chironomid hatches is having good imitations that are fished at the proper depth and with the right amount of movement, which in some cases means no movement at all. You should be constantly scanning the surface and subsurface areas of the lake for newly emerged adults or rising pupae. A quick sweep of a long-handled aquarium net reveals many clues about the day's menu.
One of the most effective methods to fish the chironomid pupa is with a floating line and strike indicator. While to some this form of fishing is similar to watching paint dry, it is a deadly way to present and maintain chironomid pupal patterns at precise depths.
The majority of chironomid emergences occur in depths of less than 20 feet, which provides the perfect situation to fish with indicators. The general rule of thumb when fishing chironomid pupae is to fish them as close to the bottom of the lake as possible, which means setting the indicator so that the fly is suspended between 12 and 16 inches off the bottom.
In most emergence situations the trout prefer to feed on the pupae closer to the bottom than higher in the water. This is particularly true in clear lakes, where feeding higher in the water increases their exposure to predators such as ospreys and loons. In many jurisdictions it is legal to fish with more than one fly and suspending two different colored pupal patterns spaced about 18 inches apart can really help narrow down specific color preferences for that particular emergence.
It is critical to watch the strike indicator closely. There are days when the strikes are aggressive and the strike indicator goes down hard, but other times it barely moves or quivers, and a slow response will miss the fish completely.
Pupal color choice should always be based on examining the real pupa or newly emerged adults or by using a throat pump to sample the live pupa in the throat of the fish. Matching pupal size and color as closely as possible is often the difference between a great day on the water compared to just the occasional hookup.
Chironomid pupae can also be fished with floating lines without strike indicators. In this method use a leader at least 25 percent longer than the depth of water being fished. For instance, if anchored in 12 feet of water I use a leader that is 15 to 16 feet in length, and I allow plenty of time for the fly to sink.
Determine where the fly is in relation to the lake bottom by using your watch to record the seconds, and when you think the fly is close to the bottom, begin a slow hand-twist retrieve. This moves the pupal pattern horizontally through the water while staying in a very narrow depth zone close to the lake bottom. If the fly hangs up on the bottom, reduce your wait time on the next cast.
This same setup can be used to wind drift pupal patterns. Try this method when there is a slight breeze on the water. Make a cast perpendicular or 90 degrees to the wind, and allow a belly to form in the line as it slowly drifts downwind. The pupa will be drifting naturally just off the lake bottom. Watch the end of the fly line for strikes, which will vary from aggressive, hard pulls to slight hesitations in the drift.
Chironomids also emerge from deep water, often in excess of 50 feet, particularly later in the season. Use full-sinking lines to imitate the natural pupal ascent from these depths.
I use a type 6 or 7 sinking line with a 6- to 7-foot leader, and cast the same length of line as the depth of the water. If I'm anchored on 50 feet of water, I cast about 50 feet of fly line. Wait for the line to sink until it is straight up and down, and then start a slow hand-twist retrieve to pass the pupal pattern through all the potential feeding zones.
Typically, the fish take the fly within a few feet of the bottom or follow it up to within 10 feet of the surface before striking. It can be exciting fishing, as the takes are not subtle.
More recently, anglers have been fishing chironomids in even deeper water, as much as 80 feet in depth. It has been effective to just suspend the pupal pattern a couple feet off the lake bottom and wait for the rod to double over. Make sure you are holding the rod securely when fishing this technique.
Regardless of the tactic or fly line type, make sure your fly is tied on with a nonslip loop knot. This simple knot significantly increases the number of fish you hook simply because the fly moves so much more naturally. As a general rule of thumb, use loop knots when fishing any fly under an indicator and natural movement is important.
The most common chironomid pupal colors include black, brown, green, maroon, and various shades of these colors. Ascending pupae often take on a silvery or silvery-gray sheen, a result of gases that build up under the pupal shuck in preparation for the adult emergence.
The two most important and most common pupal colors are a black-bodied pupa with a red wire or red holographic tinsel ribbing, and a gunmetal gray Flashabou pupa with red wire or holographic tinsel rib. The key is matching the real bugs as closely as possible in terms of size, shape, and color.
Prolific chironomid fisheries in British Columbia include Dragon Lake near the city of Quesnel and White lake near the city of Salmon Arm. Both fish well during May through mid-June. There is also a good chance to hit respective Callibaetis mayfly emergences at both these lakes during the same time period. Crane Prairie Lake near Bend, Oregon offers heavy emergences of a variety of sizes (species) of chironomid pupae through June and July. The fishing gets better as hot summer temperatures settle into the area.
Many Western stillwaters support healthy populations of mayflies. The most widespread are those found in the genus Callibaetis, the speckled-winged mayflies. The preferred habitat of mayfly nymphs is the lush emergent and submergent vegetation growing within the shoal or littoral zones of the lake. There, trout feed on the immature nymphs, migrating mature nymphs, emerging adults, newly emerged duns and egg-laying spinners.
Depending on the size of the lake and elevation, you may encounter mayfly hatches right from mid-spring through summer. Often, the emergence is most intense over a one- to two-week period.
In the majority of productive lakes, the nymphal swim to the surface of the lake attracts the most intense interest of foraging fish. These fully developed nymphs are easily recognized by their swollen and darkened wingpads. They swim on a shallow angle to the surface, where the dun or nonreproductive adult emerges.
Floating lines with 12- to 20-foot-long tapered leaders and nymphal patterns are my go-to method of presentation. I prefer to make long downwind or wind drifted casts, and allow the fly to sink close to the bottom. Use slow, 2- to 4-inch-long strips interspersed with several short, quick pulls.
Bulging or porpoising riseforms are telltale signs that the fish have switched from feeding on subsurface nymphs to the emerging adults. Look for individual feeding fish, track their movements, and place a cast well ahead of the fish using an emerger pattern on a floating line and a 12- to 14-foot leader.
This emergence also offers some great dry-fly fishing as newly emerged duns and returning egg-laying spinners are extremely vulnerable when they pause at the surface. Swirling and splashy riseforms are good indicators that some surface feeding is underway. Again, it is important to be constantly watching the lake for insect presence, fish movement, and the presence of birds that are likely also feasting on the same bugs.
There are many good fly patterns that imitate the Callibaetis and other species of mayflies found in Western stillwaters. Pheasant-tail Nymphs, Gold Bead Flashback Pheasant-tail Nymphs, Bird's Nest Nymphs, Parawulff Adams, and Parachute Adams in sizes 12 to 16 should be in your fly box.
Sheridan Lake in the Cariboo region of B.C. sees an intense but relatively short emergence of Callibaetis during June and early July. Chopaka Lake in eastern Washington has good emergences during the month of May, and Hebgen lake in Montana offers consistent mayfly fishing opportunities through July and August.
Damselflies are another common inhabitant of productive Western stillwaters. Like mayflies, the damselfly nymphs frequent the vegetation growing in the shallow areas of a lake. The damselfly nymph is a carnivore, often preying on immature mayfly nymphs, scuds, and anything smaller than itself.
The nymphs can take up to four years before emerging into the adult stage. Trout seek out both immature and fully developed nymphs. Some of the most intense feeding occurs when the mature nymphs leave the protection of the dense aquatic vegetation to complete their life cycle. This emergence swim sees the nymphs swim near the surface in search of stalks of longstem bulrush or cattails to crawl up and out of the water.
Once out of the water, the adult form emerges from the old nymphal shuck. The migrating nymphs swim in a slow, sinusoidal motion within a few feet of the surface of the lake, making them easy targets for hungry trout. Observant anglers often see the nymphs swimming in the water.
The ideal way to fish this emergence migration is with a floating line setup with a 12- to 14-foot leader and a damselfly nymph pattern that closely matches the olive/brown color of the real insects. Situate your boat so that you are casting out into the lake and retrieve your fly in the same direction that the real nymphs are heading—most often this is toward shore.
A common strategy for me is to anchor my boat right along the edge, or partially within a heavy patch of bulrush. I cast out into the lake, allow the fly to sink 3 to 4 feet down, and then start a slow retrieve of 3- to 5-inch pulls toward the boat. Remember, the real nymphs take regular pauses during this swimming adventure.
In the fall, trout search out the juvenile nymphs that are hiding in the submerged vegetation. A great way to fish with baby damselfly nymphs is to suspend them under a strike indicator, and fish the edges of weed patches or the open holes within the dense plant growth. Work the fly just off the lake bottom, and give it occasional quick irregular pulls just to add a bit of erratic movement. More often than not, the trout will eat the nymph as it just hangs there.
Newly emerged and fully developed adult damselflies are also highly prized food items. Trout move into the shallow-water stands of cattails and bulrushes and sometimes crash their bodies against the plant stems to knock the still fragile adults into the water, where they become helpless floating meals.
Windy days and downdrafts also knock hovering adult damselflies into the surface film. Make sure you have a few adult patterns in your box for those special days of frenzied surface feeding activity.
Well-known damselfly nymph patterns include Whitlock's Damsel Nymph and Kaufmann's Marabou Damsel.
Henry's Lake in eastern Idaho is well known for its prolific population of damselflies that result in heavy and prolonged emergences through the months of June and July.
No stillwater fly box is complete without a good selection of leech patterns, and although they do not emerge or hatch like an aquatic insect, they are an important food source during all open water periods. In the fall especially, leeches become a significant source of protein as fish are bulking up prior to winter ice cover.
Leeches are reclusive, typically found hiding under rocks, within woody debris, and in vegetation that covers the benthic areas of the shallow shoal zones of the lake. They are active in low-light conditions and at night, which helps explain why night fishing in shallow water during warm summer months can be so productive.
Leeches come in various colors including black, shades of brown, green, maroon, and mottled variations of all these colors. They are long-lived, and can reach lengths in excess of 8 inches when fully extended. Leeches swim in a distinctive up-and-down undulating motion that fish find hard to resist.
While there are lots of big leeches available, it is often the very small leeches that find their way into the stomachs of the trout. That is why micro leeches have become so popular. By small we are talking about patterns tied on #12 or #14 scud hooks.
Leeches can be fished with floating or with sinking lines of various densities. However, much of my leech fishing occurs along the edges of drop-offs into water less than 5 feet deep. This makes floating lines an ideal choice, with tactics similar to those described (above) for chironomid pupae.
Leeches are particularly effective when fished under an indicator. My favorite presentation is to cast into a slight breeze, and allowing the fly to drift back in a natural, drag-free drift. The combination of the up-and-down motion of the indicator, with a loop-knotted tungsten beadhead leech, makes this an ideal way to cover prime real estate of the shoal zone.
Clear intermediate sinking lines are another proven way to fish leeches in water less than about 18 feet deep. The slower sink rate of this line can be used in combination with slow strip or hand-twist retrieves to keep a leech pattern moving along just above the bottom substrate.
The edges of the drop-off can be fished with faster-sinking lines that are matched to the slope being fished. I anchor just on the edge of the drop-off, and cast out over deeper water for a retrieve that climbs up the face of the slope, but you can also anchor on the drop-off slope, and cast parallel to it. Both methods are covering prime fish-holding water.
There are many fish-catching leech patterns to choose from. Many are tied with dubbed mohair-based materials and/or with marabou, as both breathe and pulse when stripped or drifted through the water. Beadhead patterns add more flash and further irregular movement to the fly especially when tied on with a loop knot. The Ruby-eyed Leech, maroon micro-leech, and rabbit strip leech are tying styles that are consistent producers in lakes throughout the West.
These are just a few of my favorite and most dependable methods to fish productive Western stillwaters. Use them as a starting point, and as you find success, I'm sure you'll add variations to suit your local ponds, lakes, and reservoirs, and make your outings more enjoyable.
Brian Chan lives in Kamloops, British Columbia, where he is a professional fisheries biologist. He has been fly fishing in stillwaters for nearly 40 years and is a well-known author, video producer, lecturer, and angling guide. He is the coauthor with Philip Rowley of Stillwater Solutions Recipes. Rowley and Chan recently joined the pro staff of Montana Fly Company, which ties their patterns. The flies are also available from stillwaterflyfishingstore.com.