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.
- 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.