GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 266-4
Presentation Time: 9:00 AM-6:30 PM

RELATING NUTRIENT UPTAKE AND METABOLISM IN AN URBAN CEMENT LINED STREAM


SIEGGREEN, Grace M., Geology, Geography, and the Environment, Illinois State University, 119 N. Adelaide, Normal, IL 61761, O'REILLY, Catherine M., Dept. of Geography, Geology, and the Environment, Illinois State University, Normal, IL 61790, PERRY, William L., City of Bloomington, 25515 Waterside Way, Hudson, IL 61748 and PETERSON, Eric W., Department of Geography, Geology, and the Environment, Illinois State University, Campus Box 4400, Normal, IL 61790

Cement-lined streams are responsible for highly nutrient rich waters causing poor water quality and eutrophication in downstream environments, due to the lack of water infiltration into the ground. However, nutrient retention is still possible through absorption by the biota (algae and other microbes) that grow on the stream bed. This absorption, or demand, of nutrients can be monitored by measuring the rate of retention or uptake. Previous studies show that nutrient uptake is affected by the biota activity or metabolism, yet these studies are restricted to environments other than cement-lined streams. Therefore, the purpose of this study is to understand the connection between the biotic metabolism and nutrient removal in a cement-lined stream setting.

I will accomplish this by measuring the nutrient uptake of ammonia and phosphate as well as metabolism in a cement-lined stream in Bloomington, Illinois during June-August 2019. Metabolism will be measured by deploying dissolved oxygen and photosynthetic light loggers at the stream site. Collected data will be compared to understand if the dominating metabolism of the stream is from algae or microbes in the form of gross primary production (GPP) and community respiration (CR) respectively. The uptake rates will be measured by conducting in-situ uptake analyses and collecting water and biota samples in vesicles appropriate for analyte. Water samples will be tested in a laboratory for ammonia and phosphorus concentrations with an Ion Chromatograph and spectrophotometer, and biota samples will be analyzed for algal and microbial type and density by direct observation and through obtaining the ash free dry mass of samples. The uptake velocities are expected to be high (based on previously collected data), and most of the stream metabolism will be GPP due to high exposure to sunlight. In addition, the dominating biota type is expected to be algae rather than microbes due to GPP being the dominant metabolism.