Effects of Water Level Fluctuations on Nutrient Dynamics in a Shallow Lake
Hydrologic fluctuations in sediments alter microbial activity and biogeochemical processes, potentially leading to release of C, N, and P from sediments to the water column when transitioning from dry to wet conditions. These cycles may contribute to internal nutrient loading in bodies of water, and shallow lakes are particularly vulnerable due to the increased risk of exposure of littoral sediments with changes in lake level. Utah Lake, a remnant of Lake Bonneville, is a shallow freshwater lake located in the Utah Valley that receives urban and agricultural runoff and effluent from several waste water treatment plants. Water quality in Utah Lake is impaired by excess levels of phosphorus, nitrogen, and total dissolved solids. As a result of the water quality challenges in Utah Lake, it is important to understand how environmental changes, such as lake level fluctuations, impact nutrient dynamics in the lake.
This study quantifies the impact of the fluctuations in lake level on sediment nutrient dynamics to provide estimates of internal loading of C, N, and P from sediments to the water column when dry littoral sediments are re-inundated.
In collaboration with Dr. Soren Brothers, Dr. Greg Carling, and Dr. Zach Aanderud, funded by the Utah Division of Water Quality, Research Assistant: Emily Jainarain.
Impact of Frequency and Duration of Sediment Drying-Rewetting on Nutrient Release and Oxygen Demand
To determine the mass fluxes of C, N, and P associated with wetting and drying in Utah Lake’s littoral zone, this study quantifies the relationships between the frequency and duration of dry periods on the subsequent nutrient releases and oxygen demand following re-wetting through field and laboratory studies.
Rate and Magnitude of C, N, and P Fluxes from Drying-Rewetting Sediments
To understand the biogeochemical mechanisms at the sediment-water interface that influence the overall fluxes of C, N, and P, this study quantifies the rate and magnitude of nutrient fluxes following drying and re-wetting phases in littoral sediments.
Photos from the field:
