Effects of Water Level Fluctuations on Nutrient Dynamics in a Shallow Lake
Location
Logan, UT
Start Date
3-29-2022 4:15 PM
End Date
3-29-2022 7:00 PM
Description
Utah is simultaneously the fastest growing and second driest state in the United States. Periods of drought, climate variability, and a rapidly growing population put enormous pressures on waters of the state. Utah Lake, a shallow, hypereutrophic lake, is Utah's largest freshwater lake and is located in a highly urbanized watershed. Lake water levels fluctuate between 3-4 feet each year due to natural and anthropogenic factors, creating the potential for internal nutrient loading from littoral sediments and exacerbating water quality issues.
This study investigates the release of carbon and nitrogen into the water column as sediments transition from dry to wet conditions. Carbon and nitrogen fluxes were assessed during dry summer conditions and transitional fall conditions in three field sampling campaigns. Sediment and water samples were analyzed for bioavailable nutrients (PO4-P, NO3N, and NH4-N), sediment surface aquatic metabolism (production), and sediment nitrogen cycling (denitrification, mineralization, nitrification, and microbial biomass C and N). The results of this study will give insight to the influence of microbial activity at the sediment-water interface on mass fluxes, and the potential reactivity of N being loaded into the water column when dry littoral sediments become re-inundated. By quantifying the duration and frequency of wetting and drying on nutrient loading, researchers can gain insight on whether littoral sediments act as nutrient sinks or sources, and how that impacts the overall nutrient budget of the lake. This study will play a critical role in developing restoration and management plans for Utah Lake.
Effects of Water Level Fluctuations on Nutrient Dynamics in a Shallow Lake
Logan, UT
Utah is simultaneously the fastest growing and second driest state in the United States. Periods of drought, climate variability, and a rapidly growing population put enormous pressures on waters of the state. Utah Lake, a shallow, hypereutrophic lake, is Utah's largest freshwater lake and is located in a highly urbanized watershed. Lake water levels fluctuate between 3-4 feet each year due to natural and anthropogenic factors, creating the potential for internal nutrient loading from littoral sediments and exacerbating water quality issues.
This study investigates the release of carbon and nitrogen into the water column as sediments transition from dry to wet conditions. Carbon and nitrogen fluxes were assessed during dry summer conditions and transitional fall conditions in three field sampling campaigns. Sediment and water samples were analyzed for bioavailable nutrients (PO4-P, NO3N, and NH4-N), sediment surface aquatic metabolism (production), and sediment nitrogen cycling (denitrification, mineralization, nitrification, and microbial biomass C and N). The results of this study will give insight to the influence of microbial activity at the sediment-water interface on mass fluxes, and the potential reactivity of N being loaded into the water column when dry littoral sediments become re-inundated. By quantifying the duration and frequency of wetting and drying on nutrient loading, researchers can gain insight on whether littoral sediments act as nutrient sinks or sources, and how that impacts the overall nutrient budget of the lake. This study will play a critical role in developing restoration and management plans for Utah Lake.