Environmental and Biological Variability in the McMurdo Ice Shelf Ecosystem

  • C. Howard-Williams
  • R. D. Pridmore
  • P. A. Broady
  • W. F. Vincent
Conference paper

Summary

The McMurdo Ice Shelf is an ablation region on the northwestern side of the Ross Ice Shelf. The surface forms the largest non-marine aquatic ecosystem in the McMurdo Sound region with an interlinking system of lakes, pools and streams occuring across more than 1500 km2. Two major types of ice shelf morphology with different physical and biological characteristics were distinguished: “Pinnacle Ice” with many small interconnected pools and streams, and “Undulating Ice” with continuous moraine cover and discrete pools and lakes up to 104 m2. The flora of these is dominated by benthic rather than planktonic communities. Cyanobacteria which coat the base of the pools with mats and films of varying thickness are generally the most commonly occurring and abundant organisms. Benthic diatoms and coccoid chlorophytes are also found throughout the system but tend to dominate in the waters of the Pinnacle Ice rather than the Undulating Ice. There are large variations in the conductivity and nutrient content of these waters, with a marine tidal influence in some parts. The water bodies are subject to continual change as the Ice Shelf moves, with marked temporal variability in environmental conditions on a diel, seasonal and long-term (years to decades) basis. This area contains the most extensive microbial growths in southern Victoria Land and is a potential inoculum source of micro-organisms for the entire region.

Keywords

Biomass Phosphorus Nitrite Gravel Chlamydomonas 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • C. Howard-Williams
    • 1
  • R. D. Pridmore
    • 2
  • P. A. Broady
    • 3
  • W. F. Vincent
    • 1
  1. 1.Taupo Research LaboratoryDSIRTaupoNew Zealand
  2. 2.Water Quality CentreDSIRHamiltonNew Zealand
  3. 3.Department of Plant and Microbial SciencesUniversity of CanterburyChristchurchNew Zealand

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