Information on some Key Aquatic Species

Family Chironomidae: midges or chironomids. Over 100 kinds of chironomids have been reported from the Yukon arctic north slope. One of the major and successful families of insects in the arctic zone, they find suitable habitat in the abundant pools, ponds, lakes, flowing water, seepage zones and marshes of the northern Yukon (Oliver and Dillon 1997). Chironomid larvae, sometimes called "bloodworms", take one to two months to reach the pupal stage, and are important fish food. The pupae swim like wrigglers near the water surface for a few days before transforming into winged adults. The adult midges may swarm along streams or shores and are a major food source for some fish.
Family Simuliidae: blackflies. Although there are 76 different blackflies reported for the Yukon, only 55 species are formally described and named (Currie 1997). Most (41) are in the genus Simulium. At least 56 northwestern blackflies are bloodsucking species, with 26 species feeding on birds and 30 feeding on mammals. Female blackflies lay their eggs on stones in fast-flowing water. The larvae remain attached to the rocks, sometimes forming black mats when abundant, and depend on the current to bring food. Pupal stage, about 5 days long is spent in a small cocoon. Blackflies are an important fish food.
Family Tipulidae: craneflies. Some species of craneflies lay their eggs in water, larvae live in water. Adult craneflies resemble gigantic long-legged mosquitoes and are found in wet areas among tall vegetation. Eggs are laid in wet soil and the larvae of some species are found in water.
Family Culicidae: mosquitoes. Approximately 12 species of mosquitoes are known from the northern Yukon (Wood et al. 1979). Mosquito eggs are laid in rafts of several hundred on water, the larvae, known as wrigglers, are important fish food, hanging downward from the surface for about 2 weeks before entering the pupa stage. The adults emerge from the pupae in a few days.
Order Plecoptera: stoneflies. Stonefly nymphs cling to stones under water and feed on small forms of animal life. Adult stage may be reached only after several years. Adults fly near streams and mate soon after emerging.
Order Trichoptera: caddisflies. Caddisflies are an important food of round and broad whitefish in the Old Crow area (Bryan et al. 1973). Depending on species and habitat, caddisfly larvae build a case for protection from materials in their environment, sand grains, sticks, or pieces of plant leaves.
Order Ephemeroptera: mayflies. Mayflies appear in great numbers in and near water bodies, and are important food for fish. The nymph stage lives under water and is equipped with gills for breathing.

ii) Fish

The following section provides some life history information on the fourteen fish species known from the Old Crow River.

Like most salmon, chum salmon spend most of their lives in the Pacific Ocean, returning to the rivers where they were hatched to breed at about four years of age. Although chum salmon generally spawn at short distances from the sea, those in the Yukon River system travel far greater distances. Chum salmon travel up the Porcupine to spawning grounds in the upper reaches of the Porcupine and its major tributaries. Only one major spawning ground has been identified; the Fishing Branch of the Miner River. Spawning in the Old Crow River has not been documented, but a few Chum salmon are recorded as being caught as far upstream on the Old Crow River as the fish trap, Kie Koo, west of the mouth of Thomas Creek (Steigenberger et al. 1975). Spawning in the Fishing Branch occurs in late September through October (von Finster 1999). Chum salmon spawning in the Upper Yukon River is always associated with discharging or upwelling ground water. Incubation in the spawning beds and emergence from the stream bottom depends on the temperature of the ground water. After emergence, the fry migrate to the ocean early in the year.

The Chinook salmon that migrate up the Yukon River make one of the longest journeys known for this species. Those salmon that continue up the Porcupine to spawn make an equally impressive journey. "They lay their eggs, spawn. and die. They're just skinny by this point. The headwaters [of the Porcupine River], that's where the salmon goes. Chum, they go there, King salmon and coho. They are all lying on the shore. There are thousands of them and bears all the time." Peter Josie (in Sherry and Vuntut Gwitchin First Nation 1999). The female excavates a nest or redd in the stream bottom. The redd is dug in an area where suface water will flow into it through the incubation period. The time of hatching and emergence is dependent on water temperature. In the upper Yukon, spawning occurs in late July and August (McPhail and Lindsey 1970). A few adults of this salmon have been observed in the Old Crow River, but a spawning population within the Old Crow River Basin has not been confirmed (Steigenberger et al. 1975.

Although arctic char do not occur within the Park or Special Management Area, the Vuntut Gwitchin have historically fished for arctic char in the heritage fishing sites on the Firth, Babbage, and Fishing Hole (Canoe) Rivers. This use was mainly during the winter season (see section "E").

The least cisco has been recorded from the Old Crow River as far upstream as near the mouth of Surprise Creek. It is one of several species caught regularly by the Vuntut Gwitchin. However, little is known about the natural history of this species in the Old Crow Basin. Least cisco captured during an upstream migration on Shaeffer Creek in September 1999 appeared so different from those of the southern Yukon that their identification had to be confirmed (von Finster 1999). The least cisco, like most whitefish, is a remarkably plastic species, and information on this species from elswhere may not apply to the Old Crow Basin.

Lake whitefish (humpback or hump whitefish) Nuduggun Coregonus clupeaformis

This commercially valuable fish is found from Newfoundland to British Columbia and in much of northern Canada. The life history of this fish is essentially unknown for the Old Crow Basin. Although more is known about the lake dwelling populations of Great Slave Lake, the information is not applicable because the lake population use very different habitats and thus have different life history strategies. In Great Slave Lake, young whitefish feed on plankton and microscopic life, and then become bottom feeders, eating molluscs and insect larvae (McPhail and Lindsey 1970). "Most whitefish come from the lakes in late summer. You can tell the difference between the two kinds. Lake whitefish are bigger and fat. The river ones, they're thinner. Everyone likes the lake fish." Peter Josie (in Sherry and Vuntut Gwitchin First Nation 1999).

Again, little is known about the broad whitefish in this area. Although broad whitefish prefer stream habitats, there are also lake-dwelling stocks and some stocks that spend a part of their lives in standing water. In streams they feed mostly at the bottom, on aquatic insects, especially chironimid midge larvae, as well as snails, clams, worms (oligochaetes), and bottom-dwelling crustaceans (Karasiuk et al. 1993). Snails and caddisflies were the main foods found in stomachs of this species near Old Crow (Bryan et al. 1973). Wynne-Edwards (1952) reports that this fish spawns in August in the Mackenzie River around Arctic Red River. Broad whitefish spawn in the fall at or after the appearance of the first ice.

Though little is known about this fish, it appears that round whitefish prefer living in streams, and feed on aquatic insects, snails, clams, and worms (oligochaetes) living on the stream bottom (Karasiuk et al. 1993). This species has been recorded in the upper part of the Old Crow River. Caddisflies were the main stomach contents in fish caught near Old Crow (Bryan et al. 1973).

Spawning in this area has not been described, however, McPhail and Lindsey (1970) report that spawning occurs during the autumn along the shores of lakes or in streams. There the eggs are shed over the gravel, evidently without any nest construction or parental care.

In the absence of local information on this species, the following is presented as background information which may or may not be applicable to the Old Crow Basin. McPhail and Lindsey (1970) state that in the larger tributaries of the Great Slave Lake, spawning is thought to occur during late summer and early autumn. They believe that no nest is built and that the eggs are simply scattered over the gravel in riffle areas. However, they knew of no observations on spawning of these fish. Alt (1969) has observed spawning in the Kobuk River, Alaska. It occurred in the relatively swift part of the main current, both where it moved along the eroded bank and also in the middle of the channel. No spawning was observed on the gravel bars on the inside of the river where the current was slower. In optimum spawning habitat, the bottom was composed of differentially sized coarse gravel with no silt and some sand present. Alt (1969) believes that different sizes of gravel are needed to insure that the eggs lodge in the gravel.

Arctic grayling, also known as the bluefish, is a fish of the north and thrives only in clear, pure, cold water. Grayling are opportunistic feeders, and though their major prey items are insects, both aquatic and others, they will eat small fish and small mammals on occasion. Grayling feed at the surface and in mid-water, though in early spring and late fall, they also feed at the bottom (McPhail and Lindsey 1970). Juvenile grayling eat microscopic animals (zooplankton) at first, then insect larvae. In the fall, grayling may migrate from smaller tributary creeks such as Potato and Surprise Creeks (which probably freeze to the bottom in winter) into the Old Crow River and travel upstream to open water areas at the headwaters, where they occur in large concentrations (Steigenberger et al. 1974). Historical information suggests that there is also a fall migration from the tributaries in the Old Crow Flats to downstream areas of the Old Crow River and the Porcupine River. The dividing point for upstream versus downstream migration was thought to occur between the mouths of Thomas and Surprise Creeks (Steigenberger et al.1975). In spring, soon after the ice leaves the river the grayling move to shallow stream headwaters. Spawning probably occurs from early until mid-June at about the time the lake cover is breaking up. Grayling will spawn over a wide variety of substrates, including small streams over a gravel or rocky bottom. McPhail and Lindsey (1970) state that the eggs are apparently shed over the bottom without any redd construction or parental care. Grayling eggs are non-adhesive and sink quickly in the water. Riffle areas seem to be important for spawning and hatching. Grayling have traditionally been of major importance to the Gwitchin, especially in winter.

Northern pike are found in the lakes and streams of the Old Crow Flats, but little is known of their migration patterns. They have been recorded as overwintering in lakes on the Old Crow Flats and in the streams that connect them to the Old Crow River (Steigenberger et al.1974). The spring migration to spawning areas for the pike that overwinter in the Old Crow Flats has not been documented. Some pike are thought to move in spring from the Porcupine River upstream into spawning and summer feeding areas in the tributaries, including the Old Crow River (Steigenberger et al.1974). Northern pike breed shortly after the spring break-up until early July. Spawning occurs in shallow vegetation-rich areas like marshes and slow-moving rivers. The adhesive eggs are laid and scattered over the bottom or on submerged plants (McPhail and Lindsey 1970). Spawning may be controlled by the nature of the bottom, with a preference for terrestrial or dense aquatic vegetation. Fish will spawn above other substrates when these are not available (Bryon 1967). The young fish (fry) remain in shallow, weedy waters while the adults migrate to deep, cool, open waters (Sherry and the Vuntut Gwitchin First Nation 1999). Some fish eat plants from the bottom of the lake but the big fish, like jackfish, he eats other fish, even little birds." Charlie Peter Charlie Sr. (in Sherry and Vuntut Gwitchin First Nation 1999).

Widely spread throughout Canada, the longnose sucker has the most northerly distribution of the suckers and is found in lakes and brackish estuaries up to the Arctic Ocean. The natural history of this species in the Old Crow Basin is poorly known. In general, this sucker can be found in deep and very shallow water, and feeds on insect larvae and crustaceans on lake bottoms. Adults may weigh up to about 2 kg and have bright pink or red markings at breeding time. Elsewhere spawning is usually in shallow gravel streams but may also take place in outlets or the shallow margins of lakes. Breeding usually begins shortly after the melting of the ice cover on lakes in spring (McPhail and Lindsey 1970). The sucker eggs are adhesive and probably hatch in 11 days depending on temperature. Suckers show a spring dispersal from the Porcupine River to spawning and summer feeding areas in the tributaries, but little is known of these movements (Steigenberger et al. 1974). In the Old Crow area, suckers are caught in spring and summer nets set for whitefish and are used for dog food (Sherry and Vuntut Gwitchin First Nation 1999).

A member of the minnow family, the lake chub (also known as the northern chub) occurs across Canada. With an average length of only 10 cm, the lake chub lives mainly on aquatic insects in cool lakes and streams. In the Old Crow area, lake chub seem to move only locally within the lower part of the Old Crow River. Their distribution seems to favour a silty type of habitat (Steigenberger et al. 1974). Information on life history is lacking for the Old Crow Basin area. Though usually black or dark brown on the back with silvery sides, the males have noticeable reddish markings at spawning time. McPhail and Lindsey (1970) report that females with ripe or near ripe ovaries have been taken in the southern Yukon territory during late May. Females and males ready for spawning have been taken in the far north as late as August. In northern Saskatchewan, lake chub were observed amongst and underneath large rocks in river shallows during mid and late May. No nests were constructed.

The burbot is a fresh-water member of the cod family found in deep waters of lakes and large rivers, and in small streams in summer, across Canada from the Yukon to New Brunswick. Looking like a cross between a cod and an eel, the burbot has an elongated body with dorsal (back) and anal fins running from the middle of the body to the tail. Burbot are predacious, feeding mainly on other fish, but also eat aquatic insects. In the Old Crow area, this species appears to disperse to feeding areas in the spring and returns to the main rivers for winter. Burbot apparently spawn and overwinter in deep holes in the Porcupine River that are associated with the mouths of tributary rivers, such as the Old Crow River (Steigenberger et al. 1974). In the northern Yukon, the spawning time is probably January to February. Burbot spawn under ice during mid to late winter (McPhail and Lindsey 1970) in streams and lake shallows. The eggs are laid at night, under the ice, in the shallows of lakes or tributary streams, over sand and gravel, and are left unguarded. The eggs are near buoyant, small and non-adhesive. After release, they are dispersed by the action of the female's tail. To the Gwitchin, the burbot is a popular food source. The liver in particular is a favourite when boiled, cooked, frozen, or mixed with cranberries (Sherry and the Vuntut Gwitchin First Nation 1999).

Sculpins are bottom feeders, living on aquatic insects and their larvae, plankton, and crustaceans. Spawning occurs in running water in the spring (McPhai1 and Lindsey 1970). The females lay clusters of eggs which attach to the undersides of stones and the males guard the eggs. Larger fish often prey on these smaller sculpins. The average size of seven sculpins caught in 1972 in the Old Crow River was 6.1 cm (Environment Protection Board 1973). Along with the arctic grayling, this species is known from the greatest number of localities in Vuntut National Park and the Old Crow Flats Special Management Area.

The trout perch occurs mainly in lakes where it feeds on aquatic insects and small crustaceans, but spawns usually in tributary streams. In Canada this small (up to 15 cm) silvery fish is found from the Great Lakes north to the Mackenzie basin and west to British Columbia (Wooding 1972). The average size of two females caught in 1972 in the Old Crow River was 7.4 cm (Environment Protection Board 1973). In the Yukon, spawning takes place around the end of June in slow streams or along lake beaches. The eggs are fertilized in mid-water, sink to the bottom and stick to whatever they touch. The eggs hatch in about one week (Shotton 1971). Trout perch appear to have only localized movements within the lower limits of the Old Crow River and their distribution, like the lake chub, seems to favour a silty environment (Steigenberger et al. 1974).

iii) Wood Frog (Amphibians)

The wood frog (Rana sylvatica) occurs farther north than any other amphibian in North America and reaches its northernmost point in Canada in the Old Crow Flats and the Mackenzie Delta (Fournier 1997). The northernmost indication of the occurrence of frogs in the Old Crow Flats is the lake known as Frog Lake or "Ney Khwi Vun" ("frogs in the lake"). Frog Lake is south of the bend in Schaeffer Creek, just west of Drown Lake. Peter Lord reported the presence of frogs in King Edward Lake, also known as "Chattri" or "Chun Chul Tee Vun", (67^o 55' N., 140^o 10' W.) northwest of the mouth of Schaeffer Creek. He also found frogs in a small lake near the mouth of the Old Crow River (67^o 35' N., 139^o 42' W.) (Harington 1966). Lord and Harington collected two juvenile frogs and 11 tadpoles near the mouth of the Driftwood River in July 1967 (Harington 1967).

The wood frog is able to survive this far north because of two main factors: the ability of the eggs, tadpoles, and adults to tolerate lower temperatures than any other frog species, and the fastest development from egg to tadpole of any North American frog (Hodge 1976). In winter the wood frogs hibernate under forest litter and snow and can survive temperatures down to -6^o C. In the Fairbanks, Alaska, area wood frogs hibernate in shallow (3.5 cm) bowl-shaped pockets or depressions excavated by the frogs in the upper layer of the previous year's vegetation (Hodge 1976). Each pocket is overlaid by an insulating layer of new vegetation which ranges from 1.5 to 2.5 cm. Further insulation is provided by the snow layer. Years with thin snow cover result in high over-winter mortality. Wood frogs emerge and begin breeding as soon as day-time temperatures rise above freezing and before all of the pond ice has melted. In the Old Crow Flats, this would take place in about late May or early June. Wood frogs congregate for breeding in clear shallow ponds. The breeding chorus is a rapidly and abruptly repeated duck-like quack. Eggs are laid in globular masses, submerged and attached to sticks or plants, or sometimes free in the water. Tadpoles reach a length of 50 mm (same as adult length) and tranform into adults before freeze-up at about 7 to 10 weeks old (Hodge 1976).

Information on some Key Aquatic Species

i) Aquatic Insects

ii) Fish

iii) Wood Frog (Amphibians)