Letter | Published:

Nannoplankton of Marine Origin from Great Bear Lake in the Northwest Territories of Canada

Naturevolume 214pages528529 (1967) | Download Citation



GREAT Bear Lake is situated on the Arctic Circle at a point where the Pre-Cambrian Shield emerges from the adjoining Cretaceous formations. The present lake surface is 143 m above sea level, and because the maximum depth is 542 m there is a cryptodepression of 309 m. The shape of the lake could be described as amoeboid with five arms joining a central “body”. McTavish Arm, with a mean depth of 102 m, contains the deepest water at a point close to the eastern shore. The total surface area is 31,153 km2 and the volume 2,200 km3. Surface temperatures seldom exceed 4° C and, although the bottom temperature remains close to 3.56° C throughout the year, complete turnover does not occur annually1. The lake is extremely oligotrophic with oxygen saturations up to 112 per cent (14 mg/l.) in the upper 50 m in summer and minimum values very close to saturation (12.6 mg/1.) near the bottom at the end of winter. Total dissolved solids are low: 80 p.p.m. with a specific conductance of 155 µmhos. Ice cover reaches a thickness of 2 m by the end of winter and break-up does not occur until the middle of July; this is followed by an open-water season of 3–4 months, the lake becoming ice-covered during November.

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  1. 1

    Johnson, L., J. Fish. Res. Board, Canada, 23, 963 (1966).

  2. 2

    Schütt, F., Ergebn. Plankt. Exped. der Humboldt-Stiftung, 4, 1 (1895).

  3. 3

    Zimmerman, W., Z. Bot., 23, 419 (1930).

  4. 4

    Bursa, A. S., Micropaleontology, 10, 346 (1963).

  5. 5

    Craig, B. G., and Fyles, J. G., Canada Dep. Mines and Tech. Surv. Paper, 60–10, 1 (1960).

  6. 6

    Johnson, L., Syst. Zool., 13, 76 (1964).

  7. 7

    Högbom, A. G., Bull. Geol. Inst. Univ. Uppsala, 14, 241 (1917).

  8. 8

    Ricker, K. E., Canad. J. Zool., 37, 871 (1959).

  9. 9

    Holmquist, C., Berlingska Boktryckeriet, Lund (1959).

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  1. Arctic Biological Station, Fisheries Research Board of Canada, P.O. Box 400, Ste. Anne de Bellevue, Quebec

    • A. S. BURSA
    •  & L. JOHNSON


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