Lake Athabasca, Saskatchewan

delta

Lake Athabasca is located in the remote Northwest corner of the province. This is Saskatchewan's largest (7850 sq km, 283 km long and as much as 50 km wide) and deepest (max depth 243 m) lake. The lake waters and surrounding area flow northward, where they eventually empty into the Arctic Ocean through the Slave and Mackenzie River systems. Twenty-three species of fish are found in the lake (The world record lake trout was caught from here, 46.3 kg).

Lake Athabasca Map

The North shore of the lake is characterized by Precambrian shield features including exposures of bedrock, large numbers of small lakes, streams and rock pools. Conifer forests grow in areas where shallow soils have accumulated over the bedrock. Mining for uranium, gold and other minerals along the north shore resulted in the creation of Uranium City to house the mineworkers and families. However, with the closure of the last uranium mine in the 1980's the community has been reduced to almost a modern day ghost town. Unfortunately, areas of the north shore are heavily contaminated as a result of the mining activities.

On the southern shore of the lake are the Lake Athabasca Sand Dunes. This is the largest area of active sand dunes North of 58 degrees found in the world. The dunes are inhabited by 10 plant species or varieties found nowhere else in the world. There are 54 species that are rare to Saskatchewan and twelve rarities for Canada. The dunes were designated a "Provincial Wilderness Park" in 1992 after a long, half century, struggle with mining companies and government bureaucracy.

The sand dunes originate from the Athabasca sandstone formation. This formation is an ancient delta created in a large freshwater lake by glaciers and rivers eroding the Precambrian mountains about 1 billion years ago. Over the intervening time compression and chemical actions turned the delta deposits into sandstone. Subsequent erosion of the sandstone by glaciers, water and wind have produced the sand dunes that we see today.

For more information on the Athabasca Sand Dunes consult the very readable book, "Jonkers, P.M. and J.S. Rowe, (2001) The Sand Dunes of Lake Athabasca", available from the Extension Division, University of Saskatchewan, Saskatoon, SK.

Photo Gallery of Lake Athabasca Sand Dunes and Uranium City

Unfortunately, beyond the usual anecdotal comments about biting flies very little work on the aquatic insects of the area appears to be have been published in the scientific literature. Much of the biodiversity research is likely tied up in the impact and monitoring reports of the mining companies and original samples would have to be re-examined. This area should be very interesting with regard to aquatic insect biogeography as it should contain boreal forest and tundra species that have affinities with the southern refugia, Beringia and possibly the western Columbian refugium. Dosdall and Lehmkuhl (1987) inventoried the stoneflies (Plecoptera) of the region. Their conclusion was, like the fish species, the stonefly fauna was derived from postglacial immigrations from the southern refugia and Beringia with the southern refugia contributing the majority of the species. G. Hutchings collected twenty-two species in a preliminary survey of the odonates inhabiting the south shore sand dunes (Hutchings pers. comm 2002).

Aquatic insects from Lake Athabasca area:

Plecoptera (Stoneflies)

  • Choloroperlidae
    • Haploperla brevis
  • Leuctridae
    • Leuctra sp.
  • Nemouridae
    • Shipsa rotunda
    • Nemoura rickeri
    • Amphinemura sp.
    • Zapada cinctipes
  • Perlidae
    • Acroneuria lycorias
    • Claassenia subulosa
  • Perlodidae
    • Isoperla transmarina
    • Isogenoides frontalis
    • Diura bicaudata
    • Arcynopteryx compacta
  • Capniidae
    • Paracapnia angulata
    • Capnia nearctica
  • Pteronarcyidae
    • Pteronarcys dorsata

Odonata (Dragonflies & Damselflies)

  • Lestidae
    • Lestes disjunctus
  • Coenagrionidae
    • Enallagma boreale
    • Nehalennia irene
  • Aeshnidae
    • Aeshna canadensis
    • Aeshna eremita
    • Aeshna interrupta
    • Aeshna juncea
    • Aeshna sitchensis
    • Aeshna subarctia
    • Aeshna tuberculifera
    • Aeshna umbrosa
  • Gomphidae
    • Ophiogomphus colubrinus
  • Corduliidae
    • Somatochlora albicincta
    • Somatochlora cingulata
    • Somatochlora franklini
  • Libellulidae
    • Leucorrhinia glacialis
    • Leucorrhinia hudsonica
    • Leucorrhinia patricia
    • Leucorrhinia proxima
    • Sympetrum danae
    • Sympetrum internum
    • Sympetrum obtrusum

Diptera (True Flies)

  • Simuliidae
    • Simulium caledonense
    • Simulium vernum
    • Simulium tuberosum complex
    • Simulium aureum
    • Simulium venustum
    • Simulium verecundum complex
    • Simulium vittatum complex
    • Simulium longistylatum Shewell
    • Simulium decorum
    • Simulium arcticum
    • Simulium croxtoni
    • Simulium furculatum
    • Simulium corbis
    • Simulium canonicolum group
    • Stegopterna mutata
    • Prosimulium decemarticulatum

References

Ciborowski, J.J.H. and P. H. Adler. 1990. Ecological segregation of larval black flies (Diptera: Simuliidae) in northern Saskatchewan, Canada. Can. J. Zool. 86:2113-2122.

Dosdall, L.M. and D.M. Lehmkuhl. 1987. Stoneflies (Plecoptera) of the Lake Athabasca region of northern Saskatchewan and their biogeographical affinities. Can. Ent. 119:1059-1062.

Hutchings, G.E. 2005. A list of the Odonata of Athabasca Sand Dunes Provincial Wilderness Park, SK. Blue Jay 63:87-93.

Fung, K., B. Barry and M. Wilson. Editors. 1999. Atlas of Saskatchewan. University of Saskatchewan, Saskatoon, SK. 336 pp.

Jonkers, P.M. and J.S. Rowe. 2001. The Sand Dunes of Lake Athabasca, available from the Extension Division, University of Saskatchewan, Saskatoon, SK. 194 pp.