Results of ByFjord oxygenation experiment

A paper regarding the recently ended oxygenation experiment in the ByFjord on the Swedish west coast and major geochemical, toxocological and ecological results has just been published in the scientific journal AMBIO. First author of the paper is BOX-WIN project leader Anders Stigebrandt.

The paper can be downloaded from our Downloads-page and is found under the topic “Other publications”.


In a 2.5-year-long environmental engineering experiment in the By Fjord, surface water was pumped into the deepwater where the frequency of deepwater renewals increased by a factor of 10. During the experiment, the deepwater became long-term oxic, and nitrate became the dominating dissolved inorganic nitrogen component. The amount of phosphate in the water column decreased by a factor of 5 due to the increase in flushing and reduction in the leakage of phosphate from the sediments when the sediment surface became oxidized. Oxygenation of the sediments did not increase the leakage of toxic metals and organic pollutants. The bacterial community was the first to show changes after the oxygenation, with aerobic bacteria also thriving in the deepwater. The earlier azoic deepwater bottom sediments were colonized by animals. No structural difference between the phytoplankton communities in the By Fjord and the adjacent Havsten Fjord, with oxygenated deepwater, could be detected during the experiment.