Mem. of Natl Inst. of Polar Res., Spec. Issue, No. 54. 495-505, 2001

Biological characteristics of dark colored material (cryoconite) on Canadian_Arctic glaciers (Devon and Penny ice caps)

Nozomu Takeuchi1, Shiro Kohshima2, Kumiko Goto-Azuma3, and Roy M. Koerner4

1 Frontier Observational Research System for Global Change, International Arctic Research Center, University of Alaska Fairbanks, 930 Koyukuk Dr. P.O.Box 757335 Fairbanks AK 99775-7335, U.S.A

2 Biological laboratory, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8551, Japan.

3 National Institute of Polar Research, 9-10, Kaga 1-chome, Itabashi-ku, Tokyo 173-8515, Japan.

4 Terrain Sciences Division, Geological Survey of Canada, 601 Booth St., Ottawa, Ontario, K1A0E8, Canada.

Abstract

Biological characteristics of dark colored material (cryoconite) collected from Canadian_Arctic glaciers (Devon and Penny ice caps) are described. The cryoconite consists of mineral particles and organic matter. The amount of organic matter was 0.8 -13.8% dry weight. Seven taxa of snow algae (Chlorophyta and Cyanophyta) were observed in the cryoconite. The mineral particles, the algae, the bacteria, and amorphous organic matter formed small dark colored granules (cryoconite granule). The size of the granules was approximately 0.4 mm in diameter. Microscopy of the granules revealed that the granules contain bacteria with mucus like substance, and that the surface of the granules was covered with filamentous blue-green algae. These observations suggest that the granules are formed by algal and bacterial activity on the glaciers, and that the cryoconite includes a large amount of biological products. The amount per unit area of the cryoconite on the glacier surface was generally small on the glaciers (mean 48 g m-2 in dry weight). In contrast, a large amount of the cryoconite was deposited at the bottom of cryoconite holes. The small amount of cryoconite on the glacier surface means that the effect of the cryoconite on albedo reduction of the glacier surface is small.


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