Stop # 6. Chief Peter Moses Lake

Lakes and Waterfowl

Crossing the valley of the Old Crow River and following the traditional Vuntut Gwitchin heritage trail southwest, we arrive at some of the larger lakes of the Old Crow Flats: Schaeffer Lake (K'i Zhit), Whitefish Lake (Chihsho), and Willow Lake (K'ai Tedli). Among these larger lakes are many hundreds of smaller lakes of various sizes. Most of the lakes are very shallow and provide relatively warm and chemically rich summer habitat for aquatic plants, invertebrates, fish, and birds, even though some may dry out in summer and most freeze solid in winter. Because of the depth of winter freezing of the freshwater bodies, the diversity of kinds of freshwater invertebrates is relatively low. Chief Peter Moses Lake, named for an Old Crow Elder, is the site of a traditional "ratting" (muskrat trapping) camp (Figure 1.6). On the lakes of the Old Crow Flats, traditional hunting and fishing practices are carried on by the Vuntut Gwitchin. Within both Vuntut National Park and the Old Crow Special Management Area hunting and fishing are permitted and regulated through the Vuntut Gwitchin First Nation Final Agreement of 1993 (VGFNFA 1993).

Figure 1.6c
Click photo to enlarge.

Figure 1.6d

Of all the wildlife present on the Old Crow Flats, perhaps the most spectacular is the annual migration and arrival of hundreds of thousands of waterfowl. James Carroll, who trapped in the Old Crow Flats in 1920 described the influx of birds to the Flats: "From now on we saw more ducks and geese than we could have imagined. Every variety of duck came to the Flats to nest... The Flats were alive with all kinds of small birds as well as ducks and geese... It seemed to us that the whole Flats turned to life overnight - there were ptarmigan in flocks by the hundreds." (Carroll 1957).

Chief Peter Moses Lake is one of several lakes in this area that has been the site of ongoing research on both mammals, especially muskrat, and birds by biologists of the Canadian Wildlife Service and the Yukon Fish and Wildlife Branch (see Birds).

Figure 1.6a Click on photo to enlarge

Although many species of waterfowl come to the Old Crow Flats to breed and raise their young, the Barrow's goldeneye comes to the Flats to moult. Research on the ecology of Barrow's goldeneye on many of the lakes of the Old Crow Flats shows that goldeneyes chose lakes that have abundant food resources (van de Wetering 1997). Studies of various components of the ecosystem indicate that phosphorus, generally considered to be the most common growth-limiting element in fresh water, limits productivity of phytoplankton in the lakes. High levels of phophorus and the density of Barrow's goldeneye are positively related showing that the ducks select lakes that satisfy their food requirements.

It seems that ducks that travel to the Old Crow Flats to moult because the risk of predation there is low. Once they are in the Flats, they seek out lakes that will provide abundant food (van de Wetering 1997).

For the birds of the northern Yukon the problem of low temperatures in early spring or the late summer is solved by warm-bloodedness, insulation by feathers (especially inner layers such as down), and the hardiness of chicks and eggs. The terrestrial habitats occupied are only available in one short season, and so too are supplies of insect and plant food. For the many kinds of waterfowl, shorebirds, and other birds that journey to the northernYukon yearly to breed, mid summer is a time of intensive activity as adults must keep up with the demands of their growing young. Birds reproduce rapidly, following an early arrival more or less synchronized with the exposure of food supplies as snow and ice on lakes and ponds begins to melt.

Plants create or modify habitats that in turn provide microclimates that favour the survival of insects and other arthropods. As well, vegetation serves directly as food for insects. Northern shorebirds and waterfowl in turn eat insects and plant material, chiefly in lowland tundra with shallow pools and sedge-moss vegetation. Most carnivorous birds also hunt in such habitats. Semi-aquatic insects, especially the midges, or chironomids, both adults and larvae, are the most important food for fish in northern lakes and streams, which in turn feed fish-eating birds such as loons and mergansers.

Trophic Levels and Food Chains

The term trophic level is used to indicate the level of plants or animals in an ecosystem according to their feeding or energy-seeking activities. Plants belong to the first trophic level since the energy they store and use is one level up from the original solar energy they captured. The levels go from autotrophs, those organisms, mainly plants, that produce organic material from inorganic chemicals and energy, through succeeding levels of heterotrophs or consumer organisms, mainly animals. The consumers are often broken into herbivores, or plant-eaters, and carnivores, flesh-eaters. Animals that eat both plants and animals are called omnivores. A special group of consumers are the decomposers, mainly bacteria and fungi, that break down the wastes and remains of all organisms in the process of obtaining their nutrients. Those decomposers that are limited to dead tissue are called saprophytes.

To follow the transfer of energy through trophic levels ecologists visualize feeding sequences called food chains, for example; pond lily (producer) > beaver (consumer - herbivore) > wolf (consumer - carnivore). Although many arctic and sub arctic food chains are short (e.g., plants to muskrat to fox), there are also some which are just as long and complex as those in the south (e.g., dead plants to fungi to collembola to spiders to birds to humans). Food chains can be cross-connected in various ways (Danks 1981). The interlocking pattern formed by a series of food chains is called a food web. In northern ecosystems, there may be fewer species, food chains tend to be shorter, and the complexities are perhaps more easily unravelled. For example, the feeding habits of arctic grayling in the Old Crow River, studied in August 1971 by looking at stomach contents (Bryan et al. 1973), show only two major sources of food, other fish and insects. Just over 60 percent (by volume) of the stomachs contained fish, the second highest volume was caddisflies at 13 percent, and beetles, adult insects, chironomids (midges), and other flies were all at about 6 percent.

However, even in northern terrestrial ecosystems, food webs may be complex because of the various links and interactions between decomposers and plants, plants and animals, and grazers and predators. In alpine and arctic ecosystems the usual decomposers may be missing or may not function in the cold, particularly at high elevations and latitudes. Herbivores may become the main agents of decomposition, their grazing preventing an accumulation of undecomposed vegetation.

The Vuntut Gwitchin are an integral part of the food web in this area. The food web from the Vuntut Gwitchin point-of-view changes with the seasons. For example in June [Ch’adagh’oo Zrii, Birds Lay Eggs Month], the people make use of birds eggs, hunt for ducks and geese if there are no caribou or moose and also fish for whitefish (VGFN 1999). The people too are part of the food web from the insects' point-of view. "People are out on the land and the mosquitoes are out but we still carry on with our daily work out in the bush" (VGFN 1999).

Water Levels

There is presently much concern regarding the apparent decrease in the water levels in the Old Crow Flats (see Hydrology). Any change in the water levels of the lakes in the Old Crow Flats would have a profound impact on the ecosystem, food webs, and thus the livelihood of the Vuntut Gwitchin. The possibility that global scale climate change is a factor in this change has been raised.

As the Old Crow River and its tributaries meander back and forth across the Flats over time, they periodically cut through to lakes, causing a rapid draining of the lake water. This feature has undoubtedly been a part of the ecology of the Flats for many hundreds of years, but is of increasing concern to the people of Old Crow.

What may be one of the earliest accounts of draining lakes is the story of the Whitestone Mammoth. In 1967, the Elders of Old Crow told palaeontologist Dick Harington the story of a "monster" which was said to have broken out of a lake bed, travelled up the Porcupine River, and died under a bank on the Whitestone River (Harington pers, comm. 2000). Based on this story, Harington and Peter Lord located the skeleton of a mammoth under a bluff on the Whitestone River. Harington speculated that the story of the monster breaking out of a lake bed was connected to observations of lakes suddenly and violently flushing into an adjacent river as the river cuts into the lake shore.

One of the earliest reports of the draining of lakes on Old Crow Flats is found in an RCMP patrol Report by Special Constable Thomas Njootli dated 23 June 1929. In the report Njootli states: "The muskrats were considerably fewer in number than we expected; owing partly to wind storms and partly to some of the Lakes having gone dry after the ice went out and cut through the banks from the Crow River to the different lakes." (RCMP 1929).

Figure 1.6b

Peter Lord and Charlie Linklater pointed out to Geist in 1952 during their trip up the Old Crow River that there are many "dry lakes" in the Old Crow valley and that they were always where the river had cut into the banks sufficiently to cause the damage (Geist 1956?).

The history of the sequences of lake-filling and draining show in the patterned ground and marshes of the Old Crow Flats (Welsh and Rigby 1971). Some of the shallow lakes have filled with marsh vegetation and are now virtually gone. In some, the patterned ground is now only a vague ghost in the tussock and willow tundra, particularly around the higher ground around the edge of the Flats.

The catastrophic (sudden and complete) draining of lakes occurs naturally where the Old Crow River or its tributaries cut close to the banks of a lake. The problem is made worse however in that in some areas, traditional travel routes cross the narrow strip of land between a lake and a nearby river. Although this would not have been a problem in the past, changes in the means of transportation have created impacts on the terrain not found in the days of the ancestors of the vuntut Gwitchin who use these routes today. Particularly in spring and summer when the terrain is most vulnerable, the impact of repeated use of preferred trails, and possibly of some hunting and camping areas, in sensitive areas, can lead to an unnatural or human caused draining of a lake.

An example of this is that portion of the heritage trail across the Old Crow Flats which leads from Drown Lake across Schaeffer Creek. Where this trail, which is apparently used for many activities including the hauling logs of logs, leaves Drown Lake and crosses the narrow strip to the creek, there is a weakened area which is apparently close to giving way. In an attempt to prevent the draining of Drown Lake, the Vuntut Gwitchin have strengthened this weak area, using wire mesh and logs (Dennis Frost pers. comm. 1999).

Figure 1.6e Click on photo to enlarge.

Whatever the outcome of this attempt to prevent the draining of Drown Lake, it is clear that the sensitivities of the Old Crow Flats to modern travel techniques need to be studied and systematically evaluated with particular attention paid to the narrow necks and ridges between lakes, and between the perched lakes and the incised rivers and streams which drain the area. The nature of the underlying sediments and their ice content make these areas particularly sensitive to disturbance.

Ecological Integrity

The concern about changing water levels and draining lakes is one of many ecological issues that Parks Canada will address under the topic of Ecological Integrity. The draft Canadian Parks Service Policy (1993) describes ecological integrity as an ongoing condition where the structure and function of an ecosystem are unimpaired by stresses induced by human activity. Maintenance of the ecological integrity of Vuntut National Park requires respect and understanding of its ecosystems such that ecological processes are unhampered and genetic, species, and ecosystem diversity are assured for the future.