Yukon SOE Highlights - Habitat and Biodiversity

Habitat and Biological Diversity

Expansion of the road network in the Yukon over the past 50 years has led to fragmentation of wildlife habitat.

Fish habitat and migration have been affected by five hydro-electric dams in the Yukon: Lewes River (1899); North Klondike (1911); Mayo (1954); Whitehorse Rapids (1957); and, Aishihik Lake (1975). Studies show that whitefish reproduction has been poor in Aishihik Lake in some years following dam construction and fluctuating water levels have affected wetlands. Fish ladders have been installed at Lewes and Whitehorse dams and a salmon hatchery operates at Whitehorse.

Placer mining is the other major activity affecting fish habitat. New standards reduce the amount of sediment allowed in placer mine effluent and require restoration of fish habitat.

Few Yukon species are faced with extinction and the territory's biodiversity is globally significant.

There are about 30 species of plants that occur only in the Yukon or in the Yukon and neighbouring parts of Alaska. These plants survived the ice age in unglaciated areas.

bison

Two Yukon animals, the bowhead whale and the anatum peregrine falcon, are classified as endangered by the Committee on the Status of Endangered Wildlife in Canada. Wood bison are classified as threatened. Yukon animals classified as vulnerable are: the Squanga whitefish, great grey owl, short-eared owl, trumpeter swan, tundra peregrine falcon, wolverine, grizzly bear and polar bear.

Bison have been extinct in the Yukon for hundreds of years. A herd of 34 bison was introduced to the Yukon in 1985 and has become established.

The numbers of bowhead whales declined drastically in the western Arctic in the late 1800s, but they recently exhibited a recovery. The Beaufort Sea bowhead population is now the largest population in existence.

From 1970 to 1978, peregrine falcons in the Yukon declined to only a few. A national recovery plan and reductions in DDT emissions brought about a recovery and there are now over 100 breeding pairs in the territory.