Spring Excursion

I managed to hit a couple of central Alberta trout streams over the weekend. Water conditions were good; and as expected there were several species of winter stoneflies hatching along with a few midges. I did see a few fish rise but my dry fly offerings were consistently ignored. Nymphs produced similar results and it wasn’t until I switched to a marabou sculpin on a fast sink tip that I hooked my first good fish.

A nice bank where big browns like to lurk

 As for the winter stoneflies, the usual suspects were out and about – most of them in the size 16 range.



Mesocapnia projecta

Capnia sp.

There was one unexpected stonefly – one that, due to its life history, is rarely available to trout. Isocapnia integra larva prefer to live deep in the gravel; an area we refer to as the hyporheic zone. Here the only water flow is from stream water that seeps under the gravel through small aquifers, sometimes resurfacing again mid-stream, or at small spring like upwellings at the tail end of a gravel bar. It was at one of these “springs” that I spotted these stoneflies emerging – they were only in direct proximity to where water was seeping out of the ground.

Isocapnia integra adult female and nymphal exuvia

Females have reduced wings (brachypterous) and males lack wings entirely, so once they emerge they do not travel far. It is likely that they mate and lay eggs right at the spring; and the nymphs re-enter the hyporheic aquifer upon hatching. There have been reports of fully winged morphs – a strategy that may allow them to disperse when habitat conditions deteriorate.

Isocapnia integra just starting to emerge

In Alberta this species has been reported from Waterton and Banff national parks – they have not yet been documented this far from the mountains.

Isocapnia integra adult female

I also revisited a spring creek that used to produce some large browns years ago, but the upper end was still locked in ice. I did not spot any fish in the lower end on this trip but I know they are there.



A small Alberta spring creek that beckons further exploration

Trip Planning Resource

The Alberta Environment stream flow monitoring web page is starting to report flows for a few of the lower elevation streams. More monitoring stations will come on line as the gauging equipment thaws out.

Alberta Environment Stream Flows

This web page is a great resource for anglers who want to get an idea of what to expect in terms of stream flows for the areas they will be fishing. If your specific stream is not listed, you can usually get a good idea of the conditions by looking at flows for streams or rivers near your destination.

In Defence of Smaller Flies

One mistake that many fly anglers make when fishing productive trout streams is using flies that are way too big. If there is nothing actively emerging (and sometimes even if there is) the tendency is to work a searching pattern through likely holding water in hopes of a take. To most anglers a searching pattern means something large and buggy looking – the theory being that a larger, more visible fly will be more likely to generate some interest from the fish (especially if the water is stained from runoff). And if nothing else, the thinking is that the fly is at least more visible (or attractive) to the angler. This line of thinking may seem to make sense, and there is no denying that large searching type patterns produce their fair share of fish (especially if fish are feeding opportunistically), but this way of reasoning is based on a few flawed assumptions.

The first assumption is that in murky water, fish have trouble seeing a small fly, and somehow need to be helped out a little. Make no mistake, trout have excellent eyesight – they have evolved over millions of years to maximize caloric intake in all but the worst of water conditions. In addition, much of what a trout eats is small in comparison to what anglers typically offer them. Spotting and intercepting tiny nymphs in the tumbling current is what trout do for a living, day after day for their entire lives, and they do it very well. Regardless of the conditions, whether your offering is size 8 or size 18, the fish knows your fly is there.

The second assumption is that a larger fly will be more attractive to the trout because it offers more calories for the same amount of effort. This is a part of what is known as optimal foraging theory (OFT); and it is a valid assumption, but it does not take into account some of the more intricate aspects of OFT and trout feeding behavior.  If you are a trout and you have been feeding on tiny Baetis nymphs or Midge pupa for the past few days, you recognize them as food and you know exactly what to expect. The result of grabbing one out of the current is predictable and rewarding (i.e. food); and there is little or no hesitation. Compare this with something larger and unexpected. You are not sure about it – it looks like it could be edible. You could sample it at the risk of wasting valuable energy; or worse, another unpleasant encounter with an angler, or just let it pass on by. There is hesitation. Maybe even apprehension (have you ever watched how a trout reacts when a suspicious fly drifts past – that fin twitching, nervous behavior). Maybe the fish was hooked several days ago and is reluctant to take the risk. Which fly do you think will result in more takes?

I am of course ascribing some human attributes (i.e. thinking) to an animal that relies primarily on instinctive and learned behavior, but the end result is the same.

The final assumption is that most of the bugs that trout eat are as large as the impressive stonefly nymphs and caddisfly larvae that one sees wriggling in screened kick net samples. The larger organisms certainly stand out more than everything else (or at least are more active). But if you were to count up all of the different types of bugs in a kick net sample you would find that most of the time it is the tiny, unassuming mayflies and chironomids that far outnumber their more showy brethren (remember that many kick net samples are usually taken on a shallow riffle – prime habitat for stoneflies. How much of the river is actually riffle?). Big bugs are great if you can get them, but if most of the drift contains smaller organisms, then that is what you will be eating most of the time. Even if you are a bigger fish, your behavior is molded by what is most readily available (remember my example of the bear tearing open the log to get at a mouthful of insect larva - see the Introduction to Bug Bits).

There is no doubt that anglers will continue to catch their share of trout on larger searching type patterns. And these patterns do have their place even in my fly box. But I find that smaller flies that more closely represent what is actually present and active in the water consistently result in more hookups. Further, bigger fish that got that way by being a little more suspicious than the rest are far more receptive when confronted with a fly that does not look so out of place. Next time you are on your favorite trout stream try downsizing to a more natural pattern – you may find that this is just what is needed to fool the big one that has eluded you so far.

Baetis Nymphs (Blue Winged Olives)

Blue Winged Olive mayflies are one of the most common mayflies found in many rivers and streams in Alberta. The term Blue Winged Olive (abbreviated as BWO) is often applied to any small olive mayfly with dusky gray wings and can include species from several genera within the mayfly family Baetidae (Acentrella, Baetis, Cloeon, Diphetor, Plauditus and Procloeon). In a stricter sense the moniker is intended to specifically cover mayflies in genus Baetis, but since many of the other closely related genera have similar appearances and habits, these groups are usually all lumped together as simply Blue Winged Olives (also known as the Baetis complex).

The Baetis complex can produce some of the most consistent hatches of the season; often drawing fish to the surface in large numbers where they can be seen gently sipping crippled emergers or duns from the drift. BWO hatches are usually the first mayfly hatches to materialize in the spring and often extend late into the fall. The importance of this hatch cannot be overstated, and small BWO patterns should be standard in any fly angler’s repertoire. But while BWO emergers and duns can be significant throughout the fishing season, it is the tiny Baetis nymphs that draw the most attention early in the spring.

As the water starts to slowly warm, aquatic insects that have spent the winter in the nymph phase of their life cycle become much more active – moving from deeper pools and runs to shallower riffles and feeding areas along the banks. On fertile streams like the Bow River, Baetis nymphs form a significant part of the biomass. With so many of these tiny nymphs moving about, and sometimes getting caught in the drift, the fish quickly form a search image. This is a very important point – it means that the fish have learned that any small olive tidbit with the general shape of a Baetis nymph is likely safe to eat. Tie on a Baetis nymph and the odds are stacked in your favor.

Baetis nymphs range from 3 to 10 mm long. Colors can be shades of light to medium olive, olive brown or tan, with mottled medium olive being the most common. There are several commercial patterns that can be used to imitate a Baetis nymph; one of the most popular being the Pheasant Tail Nymph. The Pheasant Tail can be an effective pattern in size 16 or 18 but the color is generally a little dark compared to most Baetis nymphs. I like to use a fly tied in a similar format to the old reliable Hare’s Ear:

                                    Hook: Mustad 3399 (or equivalent), #16-18

                                    Thread: 8/0 medium olive

                                    Tails: 3 mallard flank fibers, olive

                                    Rib: fine silver wire

                                    Abdomen: medium olive dubbing

                                    Wing Case: mottled brown turkey quill

                                    Thorax: medium olive rabbit dubbing (a few hairs picked out as legs)

I also tie two other color variations where I mix in a little tan or amber dubbing with the medium olive to get a slightly mottled appearance.

A Midge Primer

With today’s dump of snow many anglers will likely be holed up some place warm – perhaps tying flies or dreaming of days yet to come. A few open streams may see fishable conditions at some point over the long weekend (depending on the rate of snow melt), but for the most part, conditions will not be favorable. For lake anglers, it will be a few weeks yet before the ice comes off the local potholes.

To help inspire those of you who may be tying Chironomid patterns this weekend, I have posted a link to an amazing YouTube video. This video clip is part of the Bugs of the Underworld DVD produced by Ralph and Lisa Cutter. The video was filmed entirely underwater from the trout’s perspective and really shows how a typical chironomid acts as it rises to the surface and emerges in its natural environment.

http://www.youtube.com/watch?v=NGQEPZqNZU8

I don’t know that anyone has come up with a scheme to effectively imitate the wiggling action of the pupa, and in my opinion the size, silhouette, and color of the naturals are far more important than any concessions that would need to be made to match the swimming behavior. The trout’s eye view perspective should give you a few things to ponder as you design new pupa and emerger patterns at the vise.

A Change of Plans

With some of the central Alberta trout streams set to open on April 1^st, I was hoping to spend Sunday poking around in a few of my favorite haunts so that I might provide an update on hatches and general stream conditions. Unfortunately both the weather and personal commitments on Sunday necessitated a change in plans; so Saturday morning found me on a stream that I seldom fish these days – the Bow River. I like fishing the Bow River and there is no question that it is an exceptional trout stream. It’s just that it generally falls short in providing one of the key elements of an enjoyable day on the water – solitude. So to make this work I knew I needed to get an early start and put several kilometers between me and the access as quickly as possible. My strategy worked, and for the better part of the day I had an entire run all to myself.

So there I was watching the sun rise, it was -5 Celsius, and not a bug in sight. Undeterred, and inspired by the spectacular view, I tied on a small Baetis nymph (a typical searching pattern for this time of year) and worked the pockets along the bank. Result number one was having to pause to de-ice my rod guides every few minutes; result number two was hooking several good sized rainbows. And so the morning went – catching fish as the day slowly warmed, and pausing on occasion to just sit and take it all in.

As the temperature nudged above zero a decent chironomid hatch began to materialize. These minute midges were barely 3 mm long (think size 24). I am sure that the fish were plucking the occasional rising pupa from the drift but these tiny tidbits were not enough to incite selective feeding. I continued to fish the Baetis nymph till noon with steady success and decided to packed it in when the hordes of anglers finally caught up to me.

Adult Chironomid (Midge) on the Bow River