Skip to main content

Oscillations of algal biomass, nutrients and dissolved oxygen as a measure of ecosystem stability


Graphic presentation of weekly rates of change of algal biomass (expressed as chlorophyll a) and nutrient and dissolved oxygen concentrations can be regarded as harmonic oscillation motion. Maximum amplitudes of these oscillations provide a useful tool to assess the degree of stability of aquatic ecosystems in relation to their trophic state. Data sets from seven different lakes ranging from hypereutrophic to oligo-mesotrophic were processed using a computerized method. The high values of oscillation amplitudes of approximately 150 μg l−1 wk−1 chlorophyll a, 500 μg l−1 wk−1 ammonia nitrogen, 50 μg l−1 wk−1 soluble reactive phosphorus and 10 mg l−1 wk−1 dissolved oxygen, indicated strong ecosystem instability, while low values of less than 10 μg l−1 wk−1 of chlorophyll a, 20 μg l−1 wk−1 ammonia nitrogen, 2 μg l−1 wk−1 soluble reactive phosphorus, and 3 mg l−1 wk−1 dissolved oxygen represented a stable system. Oscillation amplitudes of the chlorophyll a values were found to be the most representative indicator of ecosystem stability.

This is a preview of subscription content, access via your institution.


  • BaricaJ., 1974. Some observations on internal recycling, regulation and oscillation of dissolved nitrogen and phosphorus in shallow self-contained lakes. Arch. Hydrobiol. 73/3: 334–360.

    Google Scholar 

  • BaricaJ. 1989. Unique limnological phenomena affecting water quality of Hamilton Harbour, Lake Ontario, J. Great Lakes Res. 15(3) 419–430.

    Google Scholar 

  • BaricaJ. & L.Muir, 1980. Hypertrophic Ecosystems. Developments in Hydrobiology 2. Dr. W. Junk Publishers, The Hague, 348 pp.

    Google Scholar 

  • Barica, J., H. Kling & J. Gibson, 1978. Chlorophyll a, nutrients and dissolved oxygen in eight small lakes near Erickson, southwestern Manitoba. Fish. & Mar. Report No. 94.

  • Barica, J., C. Vieira & M. Fellowes, 1992. Oscillations of algal biomass nutrients and dissolved oxygen: methodology and data analysis. NWRI Contribution No. 92-201.

  • Burns, N. M., F. Rosa & C. H. Chan, 1976. Lake Erie water chemical data 1970–1971. Canada Centre for Inland Water Report No. 16.

  • FAO (U.N. Food and Agricultural Organizations, South China Sea Fisheries Development and Coordination Programme), 1976. Nutrient dynamics in eutrophic inland waters used for aquaculture. SCS/76/NT/24, Manila.

  • IJC (International Joint Commission), 1989. Report on the Great Lakes Science Advisory Board, Windsor, Ontario, 92 pp.

  • MOE-DOE (Ontario Ministry of the Environment & Canada Department of the Environment), 1988. Severn Sound Remedial Action Plan. Part 1. Environmental Conditions and Problem Definition. Toronto, Ontario.

  • RosaF., 1987. Lake Erie Cental Basin total phosphorus trend analysis from 1968 to 1982. J. Great Lakes Res. 14(4): 667–673.

    Google Scholar 

  • StevensR. J. J. & M. A.Neilson, 1987. Response of Lake Ontario to reductions in phosphorus load, 1967–82. Can. J. Fish. Aquat. Sci. 44: 2059–2068.

    Google Scholar 

  • WCED (U.N. World Commission on Environment and Development), 1987. Our Common Future. Oxford Univ. Press, Oxford and New York, 400 pp.

    Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Barica, J. Oscillations of algal biomass, nutrients and dissolved oxygen as a measure of ecosystem stability. Journal of Aquatic Ecosystem Health 2, 243–250 (1993).

Download citation

  • Issue Date:

  • DOI:


  • ecosystem stability
  • eutrophication
  • algae blooms
  • trophic state
  • harmonic oscillations