Hydrobiologia

, Volume 172, Issue 1, pp 51–61

Nitrogen dynamics in two antarctic streams

  • Clive Howard-Williams
  • John C. Priscu
  • Warwick F. Vincent
Rivers and streams

DOI: 10.1007/BF00031612

Cite this article as:
Howard-Williams, C., Priscu, J.C. & Vincent, W.F. Hydrobiologia (1989) 172: 51. doi:10.1007/BF00031612

Abstract

The many glacier meltwater streams of southern Victoria Land flow through catchments where life forms are almost entirely microbial. Allochthonous inputs of nitrogen from two study streams near McMurdo Sound were derived mostly from the melting glaciers (ca. 100–200 mg N m−3) with some originating from N2-fixation by heterocystous cyanobacteria (max. 939 mg N m−2 year−1). Thirty to fifty per cent of the glacier derived N was dissolved organic N and a major proportion of this was identified as urea N which was utilised by the rich algal and cyanobacterial mats in the streams. A nutrient budget for Fryxell Stream was estimated, quantifying uptake of urea-N and dissolved inorganic N and the release of dissolved organic (non urea) and particulate N by the stream communities. An index of in-stream nitrogen processing, the Net Uptake Length Constant in these streams was compared with that from temperate climates and was found to be similar. Despite the influence of low temperatures on microbial activity (mean daily water temperature = 5 °C) nutrient removal rates from these antarctic streams are high because of the large standing stock of microbial biomass there.

Key words

ammoniumAntarcticablue-green algaecyanobacterianitrogennitrogen-fixationorganic nitrogen

Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • Clive Howard-Williams
    • 1
  • John C. Priscu
    • 2
  • Warwick F. Vincent
    • 1
  1. 1.Taupo Research Laboratory, Division of Marine and Freshwater Science, DSIRTaupoNew Zealand
  2. 2.Department of BiologyMontana State UniversityBozemanUSA