Life in the calcium chloride environment of Don Juan Pond, Antarctica
B. Z. SIEGEL*, G. MCMURTY†, S. M. SIEGEL‡, J. CHEN‡ & P. LAROCK§
*Pacific Biomedical Research Center, University of Hawaii, Honolulu, Hawaii 96822
†Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822
‡Department of Botany, University of Hawaii, Honolulu, Hawaii 96822
§Department of Oceanography, Florida State University, Talahasee, Florida 32306
DON JUAN POND, which contains saturated calcium chloride brine, is in the south fork of the dry Wright Valley of Antarctica at latitude 77°33′S and longitude 167°10′E, and has been controversial almost since its discovery in 1961. Meyer et al.
1,2 reported a sparse microflora of four species of heterotrophic bacteria and a yeast. Cameron, Horowitz and colleagues3,4, using the Antarctic dry valleys as the best available natural simulation of Mars, reported that many areas were virtually sterile and, at most, limited to sparse bacterial populations. Field work5–10 has revealed a more abundant and varied microflora of yeasts, blue-green algae, fungi and bacteria, especially in the bottoms of frozen freshwater lakes. However, reports point to an extreme dry valley–exposed rock South-Polar biome consisting predominantly of heterotrophic forms, mainly prokaryotic with occasional fungal associates. If this is correct Don Juan Pond must, like the dry valleys generally, consist only of converter–consumer populations lacking extensive capability for continuous carbon reduction. Cameron has emphasised the ecological restrictions on the activity and distribution of algae in the dry valleys and mentions no algal or other autotrophic forms in his discussion of Don Juan Pond, even though thin organic layers were found 2 m below the 15–20 cm of standing water11. However, in the course of a mercury sampling programme during the austral summer of 1978–79 we observed an extensive, irregular pellicle or mat-like structure 2–5 mm thick but extending 500–600 m2 over much of the western part of the Don Juan Pond salt flats.
||Meyer, G. H. Polar Rec. 11, 317 (1962).
||Meyer, G. H., Morrow, B., Wyss, O., Berg, T. E. & Littlepage, J. L. Science 138, 110 (1962).
||Cameron, R. E., Honour, R. C. & Morelli, F. A. in Extreme Environments Mechanisms of Microbial Adaptation (ed. Heinrich, M. R.), 57 (Academic, New York, 1976).
||Horowitz, N. H., Cameron, R. E. & Hubbard, J. S. Science 176, 242 (1972).
||Friedmann, E. I. Antarctic J. 12, 26 (1977).
||Friedmann, E. I. & Ocampo, R. Science 193, 1247 (1976).
||Holm-Hansen, O. Phycologia 4, 42 (1964).
||Vishniac, W. V. & Mainzer, S. E. Antarctic J. 7, 88 (1972).
||Drouet, F., Polar Rec. 11, 320 (1962).
||Uydess, I. L. & Vishniac, W. V. in Extreme Environments, Mechanisms of Microbial Adaptations (ed. Heinrich, M. R.), 29 (Academic, New York, 1976).
||Mudrey, M. G. Jr, Torii, T. & Harris, H. Dry Valley Drilling Project (DVDP) Bulletin, 85 (August, 1975).
||Karl, D. M. & LaRock, P. A. J. Fish. Res. Bd Can. 32, 599 (1975).
||Casselman, W. G. Histochemical Techniques (Methuen, London, 1959).
||Glick, D. Quantitative Chemical Techniques of Histo- and Cytochemistry (Interscience, New York, 1963).
||Hawk, P. B. Physiological Chemistry, 4th edn. (Blakiston, Philadelphia, 1914).
||Pearse, A. G. Histochemistry, (Churchill, London, 1968).
||Siegel, S. M. in The General and Comparative Biology of Terrestrial Organisms under Experimental Stress Conditions, Semiannual Report Contract No. NASw-767, National Aeronautics and Space Administration, 1 (1965).
||Siegel, S. M., Speitel, T. & Stoecker, R. Cryobiology 6, 160 (1969).
||Siegel, S. M. Univ. Hawaii Botanical Science Paper No. 31, 1 (1973).
||Handbook of Environmental Control 3 Water Supply and Treatment (ed. Bond, R. & Straub, C.) 345388 (CRC Press, Cleveland, 1973).
||Biochemist's Handbook (ed. Long, C.) 10291032 (Van Nostrand, Princeton, 1961).
© 1979 Nature Publishing Group