Oxygen depletion in stratified lake waters

This project is a collaboration between APHYS and the Eawag department: Surface Waters – Research and Management. The focus of this research is to understand the intensity and temporal dynamics of oxygen depletion in the hypolimnion of lakes, as a response to the in-situ biogenic productivity of organic matter. The goal of this interdisciplinary research study is to:

  • quantify the areal hypolimnetic mineralization rate (AHM) as a function the lake-topographies and nutrient supply (level of trophy)
  • characterise the reaction of AHM during the current oligotrophication
  • identify the locations of AHM in the hypolimnion, and
  • relate AHM and sediment oxygen uptake with the organic matter content in the sediment.

Figure shows two oxygen microprofiles across the water–sediment–interface and the DBL thickness in 45 m (blue) and 133 m depth (red) in Lake Geneva.