Protozooplankton and Microzooplankton Ecology in Lakes of the Dry Valleys, Southern Victoria Land

  1. John C. Priscu
  1. Mark R. James1,
  2. Julie A. Hall2 and
  3. Johanna A. Laybourn-Parry3

Published Online: 16 MAR 2013

DOI: 10.1029/AR072p0255

Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica

Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica

How to Cite

James, M. R., Hall, J. A. and Laybourn-Parry, J. A. (1998) Protozooplankton and Microzooplankton Ecology in Lakes of the Dry Valleys, Southern Victoria Land, in Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica (ed J. C. Priscu), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR072p0255

Author Information

  1. 1

    National Institute of Water and Atmospheric Research Ltd., Christchurch, New Zealand

  2. 2

    National Institute of Water and Atmospheric Research Ltd., Hamilton, New Zealand

  3. 3

    Department of Physiology and Environmental Science, University Of Nottingham, Loughborough, Uk

Publication History

  1. Published Online: 16 MAR 2013
  2. Published Print: 28 JAN 1998

ISBN Information

Print ISBN: 9780875908991

Online ISBN: 9781118668313

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Keywords:

  • Desert ecology—Antarctica—McMurdo Dry Valleys

Summary

Antarctic lakes are extreme environments with unique characteristics including lack of wind-driven mixing, low planktonic abundance and species diversity, and dominance by microbial communities. There have been several studies of the phytoplankton community structure and distribution in McMurdo Dry Valley lakes, but very little is known of the protozoo- and microzooplankton communities in these lakes. This chapter combines published data from limited studies to date with new distribution and experimental data on Lakes Vanda and Bonney describing the physical and chemical features which influence their distribution and trophic interactions. Diversity and abundance of ciliated protozoa was greatest in the more productive lakes (Bonney and Fryxell). New data on seasonal distribution of protozoa in Lake Vanda showed there was a small overwintering population dominated by Euplotes and Askenasia. Askenasia and other members of the Didinidae dominated the spring increase in abundance with Euplotes increasing in abundance in the austral summer, potentially in response to increased bacterial abundance. Four distinct communities were found in the permanently stratified Lake Vanda: the community just below the ice in the upper euphotic zone consisted of Askenasia and Urotricha; the lower isohaline cell contained several taxa including Askenasia, Monodinium, and a spirotrich; heliozoa dominated the transition zone to saline water; and the community at 60 m was almost exclusively the bacterivorous Euplotes. Ciliated protozoa and rotifers were absent from depths >64 rn and transplant experiments demonstrated these groups could not survive in the anoxic bottom waters despite their presence in similar waters in temperate lakes. Their absence is probably because of toxic chemicals and permanent anoxia. Observations in Lake Vanda suggest the structure and vertical stratification of protozoan communities are principally determined by food resources, but low abundance and grazing rates suggest they do not control phytoplankton or bacterial populations.