Laboratory and Field Observations of \textit{Microcystis aeruginosa} in nearly homogeneous turbulent flows

ORAL

Abstract

\textit{Microcystis aeruginosa} is a single-celled cyanobacterium, forming large colonies on the surface of freshwater ecosystems during summer, and producing a toxin (microcystin) that in high concentration can be harmful to humans and animals. In addition to water temperature, light and nutrient abundance, fluid motion is also an abiotic environmental factor affecting the growth and metabolism of \textit{Microcystis}. Systematic investigations in a laboratory bioreactor are paired with field measurements in the lacustrine photic zone from two sites in Lake Minnetonka (MN) to ensure that dissipation levels, water temperature, dissolved oxygen and pH are correctly reproduced under laboratory conditions. Laboratory results for biomass accrual and photosynthetic activity suggest that turbulence levels within the range observed in the field, mediates the metabolism, rather than the cell population growth, of \textit{Microcystis aeruginosa}.

*This work was supported by the NSF Graduate Research Fellowship and University of Minnesota start-up funding

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Authors

  • Anne Wilkinson

    • University of Minnesota

  • Miki Hondzo

    • University of Minnesota

  • Michele Guala

    • University of Minnesota
    • Saint Anthony Falls Laboratory, Department of Civil, Environmental, and Geo- Engineering, University of Minnesota
    • St. Anthony Falls Laboratory, University of Minnesota
    • St. Anthony Falls Laboratory , Dep. Civil , Env. and Geo Eng. , UMN