Biosciences Seminar Series - Winter 2017
16 February 2017 - 1pm - Zoology Museum
The effects of oxygen availability and turbulence on water quality in lakes and reservoirs
Our second seminar of the winter term will be presented by Dr Lee Bryant from the Research Unit for Water, Environment and Infrastructure Resilience (WEIR) at Department of Architecture and Civil Engineering at the University of Bath. Lee is interested in biogeochemical cycling in aquatic systems, especially the influence of oxygen cycling and turbulence/aeration, or the mechanisms and consequences of mass transport of nutrients, metals etc. at the water/sediment interface. Her current projects focus on the effects of seasonal algal blooms on marine benthic oxygen dynamics; the geochemical, microbial and hydrologic characteristics of storm runoff loads within an informal settlement; and the influence of bioturbation and respiration on oxygen and trace metal cycling.
Oxygen and mixing conditions in aquatic systems have a significant influence on the biogeochemical cycling of nutrients, metals, and other species at the sediment-water interface; these fluxes often control water quality in lakes and reservoirs. In an effort to counter problems with decreased water quality stemming from anoxic conditions, engineered techniques such as hypolimnetic oxygenation systems are being used more and more prevalently to increase aquatic oxygen concentrations and reduce concentrations of deleterious soluble species.
Decreased oxygen levels in oceans are also becoming increasingly problematic due to enhanced anthropogenic effects and global warming. In both freshwater and marine systems, fluxes of oxygen, nutrients, and other chemical species are
known to be strongly controlled not only by concentration but also by turbulence such as internal waves; however, hydrodynamics can be highly variable and effects on biogeochemical cycling and corresponding water quality are not currently understood.
|From Muller, Bryant et al. 2012|
Based on in-situ microprofiler and aquatic eddy correlation measurements, results will be presented from three process studies focusing on (1) the effects of internal waves (e.g., seiches), (2) bioturbation, and (3) engineered hypolimnetic oxygenation / aeration on sediment-water fluxes of oxygen and manganese in lakes and reservoirs. These studies will be used to highlight the physical and chemical processes controlling biogeochemical cycling and related water quality in aquatic systems.