Among the 66 native freshwater fish species in British Columbia, fly anglers target a mere 15. This includes the five salmon species, bull trout, Dolly Varden, coastal and westslope cutthroat trout, rainbow trout (including steelhead), and Arctic grayling. To a lesser extent fish like pike, walleye, lake trout and sometimes lake whitefish are also the quarry of fly anglers in northern BC. Then there are species like mountain whitefish that are often an accidental catch on the fly. As a sport fish mountain whitefish is largely ignored, but given its abundance in the province and that it is generally easy to catch, anglers should give this so called nondescript fish a second chance.

Sadly many anglers consider mountain whitefish to be uninspiring and relegate it to coarse fish status. It is usually small, not particularly pleasing to the eye, smells a little too fishy – as funny as that may sound, and does not have the same acrobatic abilities as its cousins in the salmonid family. How often do you see a grip and grin of a mountain whitefish?

The story of mountain whitefish mirrors that of another salmonid – bull trout. Not too long ago anglers also had a negative opinion of bull trout. It was menace that needed to be eliminated as it competed with anglers for trout. Today anglers have changed their perceptions and highly regard bull trout and it is even protected by provincial fishing regulations. So the question beckons: 'Are mountain whitefish just a nuisance competing with trout for food and habitat? Or can mountain whitefish lose the black sheep status and become as revered status as the other salmonids?' Anglers' attitudes are starting to change with many recognizing that fishing for mountain whitefish can be very rewarding.

Searching for mountain whitefish

Mountain whitefish, sometimes called Rocky Mountain whitefish, are currently classified as Prosopium williamsoni, and with another eight species of whitefish (Coregoninae) are grouped within the salmonid family. Apart from the adipose fin, mountain whitefish do not look a lot like salmon. The scales are large compared to the other salmonids and the mouth is small and on the underside of the head. The dorsal side can be light brown to gray in colour; the sides are pale yellow-gold to silver and the belly is white.

Mountain whitefish are unique to North America. They are found as far south as California and as far north as the Yukon and Northwest Territories. They are also on both sides of the Rocky Mountains. In British Columbia mountain whitefish are predominantly an interior species, with none to be found on Vancouver Island, Haida Gwaii or other coastal islands. There are populations closer to the coast in rivers like the Fraser and Skeena that extend quite a way inland. Systems like the Upper-Fraser, Nechako, Parsnip, Peace, Columbia, and Kootenay Rivers all have abundant and healthy populations of mountain whitefish.

Biology of mountain whitefish

Although mountain whitefish are mostly a river fish, there are three distinct life histories: those that live entirely in rivers, those that stay entirely in lakes, and those that migrate between lakes and rivers. There is no anadromous life history in mountain whitefish.

Riverine mountain whitefish occupy deep runs and riffle water during spring and summer. The runs are usually four-feet or deeper with surface current that appears uniform in speed. When in riffle water, mountain whitefish often reveal themselves by 'flashing'. Flashing happens when the sun's rays reflect off of the fish's silver sides as it darts sideways in the current intercepting nymphs. Experienced anglers routinely use flashing to locate fish.

From late August to September mountain whitefish start to aggregate in large schools in deeper pools. These deeper pools are often found just below fast moving riffle water that provide food and oxygen for the fish. Usually the fish will be stacked right at the head of the pool, but do not ignore the tail-out.

Mountain whitefish reach maturity around six years of age and can live for 17 years, but a 23 year old specimen was found in British Columbia, and there are reports from Alberta of a specimen that lived for 29 years. The adults spawn in the fall, but instead of building a redd, the female scatters anywhere from 1,000 to as much as 15,000 eggs over gravel. The males then compete among themselves to fertilize the eggs, and quite often more than one male will fertilize the eggs. The eggs then incubate over winter and the fry emerge in the spring to early summer.

Mountain whitefish are opportunistic bottom feeders. Although their diet mainly consists of larval or nymph stage aquatic insects, the eggs of other spawning fish as well as the occasional small fish is also consumed. Because the mountain whitefish diet is dependent on what is available, it can vary according to region and habitat. Research on mountain whitefish in Montana rivers showed that chironomid larvae (bloodworms) and pupae make up anywhere from 40 to 50 per cent of their diet, mayfly nymphs 15 to 25 per cent and the rest being caddisfly larvae and stonefly nymphs. This is very different in north central BC where the mountain whitefish diet consists of up to 70 per cent mayflies nymphs, with the remaining 30 per cent split between chironomid and caddisfly larvae and pupae, and stonefly nymphs. It is worthwhile to pick up a few river rocks to see what is crawling underneath to get an idea what the fish are feeding on. Knowing this will allow you to best 'match the hatch', and hopefully improve your chances.

An interesting morphological adaptation among mountain whitefish is the “pinocchio”. It is named after the famous puppet as it has an elongated nose just like Pinocchio. The fish use their extended bulbous to forage and burrow in the gravel for nymphs and other invertebrate food items. It then inhales the dislodged and drifting food items with its tiny mouth, located on the underside of its head. The location of its mouth also affects how the fish takes a fly. Takes are mostly a soft tap-tap, and sometimes it is so subtle that you almost need a sixth sense to detect the strike.

Tactics, flies and equipment

Most of your success will be with smaller nymph imitations tied onto size 12 to 20 hooks. Flies like the Copper John, Pheasant Tail, Prince and Gold Ribbed Hare's Ear nymphs and variations of these established patterns should produce well. On occasion a larger stonefly nymph tied on a size eight (and even a size six) hook will catch larger fish up to 16 inches.

There are two main approaches to presenting nymphs to mountain whitefish: long line or short line nymphing. Mountain whitefish tend to hold mostly in water more conducive for long line nymphing. That being said mountain whitefish has been caught using the various versions of short line nymphing.

In long line nymphing a fair amount of fly line is used to present the fly at a distance, usually 15-feet or more. With this method a strike indicator is almost always employed to assist in seeing the strike. The strike indicator also helps to regulate the depth at which the fly is drifting. Typically the distance between strike indicator and fly should be one and a half to two times the water depth. To present the fly, cast upstream, throw in a few upstream mends in the fly line to prevent drag on the fly and point the rod at the strike indicator as it travels downstream. It is very important to present the fly drag free, as any drag will be perceived as unnatural and will be refused. When there is any movement by the indicator, such as slowing down, stopping or sideways movement, lift the rod tip. It is probably a fish, but sometimes the line could be snagged on the bottom. Mountain whitefish will often pull the strike indicator beneath the surface, making it easy to see the strike and a good opportunity to teach beginners nymphing.

In short line nymphing the angler usually wades up to within one rod length of the fish. No fly line should touch the water as it will cause drag on the nymph. There are many different approaches to presenting nymphs with a short line, but high sticking is probably the most popular in North America. High sticking presents a heavily weighted nymph on short drifts that are drag free and close to the bottom. With the target hole in front of you, flip the fly just upstream from the target. Using an extended arm, point the rod tip upwards approximately at a 45 degree angle to maintain a straight line without creating slack in the leader. The leader has to be without slack otherwise it would be nearly impossible to detect a very subtle strike. As soon as there is a slight hesitation or unnatural movement in the leader, lift the rod tip. You can use a strike indicator with this method to help you see the strike.

Mountain whitefish do feed on the surface and will rise on the rare occasion for dry flies. Use small dry flies imitating mayflies and midges. A good selection of size 14 to size 20 Adams, Blue Wing Olives, Blue Duns, Pale Morning Duns, and Trico imitations will cover most situations.

A mountain whitefish rise is easily recognized as being splashy. This is because mountain whitefish hold close to the bottom, even when feeding on floating insects and to ensure they can intercept floating insects they swim up fast breaking the surface causing a big splash. This is different from trout, as they often hold higher up in the water column while they gently sip floating insects. This difference in feeding style requires that you set the hook differently for mountain whitefish. Unlike trout, where you wait a split second before lifting the rod tip, mountain whitefish require a very quick reaction using soft hands. The fast response is needed as you almost have to anticipate the strike to react fast enough for a successful hook set. Soft hands are essential as a hard hook set will pull the fly out of the fish's mouth. The idea of a fast response and soft hands may sound contradictory, but is quite possible with a bit of practice. A good way to compensate for a lack of soft hands is to use a fly rod with a soft tip.

Fly rods with a fairly soft medium-fast action rated from three to five weight and eight- to nine-feet in length are ideal for mountain whitefish. These, paired with any decent quality fly reel loaded with a weight forward floating fly line, will cover nearly all fishing situations.

When fishing nymphs, use nine-foot leaders that taper down to 4X or roughly six-pound break strength, and this combined with 4X tippet will account for 90 per cent of your fish. Use fluorocarbon instead of monofilament for nymphing as it is less visible to fish and sinks faster. For dry fly fishing substitute the fluorocarbon with monofilament leader and tippet, and add 5X to 6X tippet as mountain whitefish can be leader shy. Mountain whitefish can also be incredibly selective. Try to 'match the hatch' as close as possible with emphasis on the size and colour of the fly. Make sure you have a drag-free drift as even the slightest amount of drag will cause the fish to ignore your fly.

Mountain whitefish is a species of contradictions. Although it is a salmonid, mountain whitefish has not been a prized game fish, but is often relegated to coarse fish status. It is easily caught by beginner anglers, but can also be a challenge to experienced anglers – requiring a quick draw, soft hands and small flies. Regardless of these sentiments, mountain whitefish are generally easy to catch and are found in many rivers and streams with easy access. It is the fish for everyone, they are native to BC, and there are lots of them.  

Blacksheep of the Salmonid Family:

Fly-fishing for mountain whitefish

by Danie Erasmus

First published in               Mar/Apr 2011