CAN PHRAGMITES AUSTRALIS BE USED AS A BIOMARKER FOR TRACE METAL POLLUTION

Utah Lake is the third largest freshwater body water west of the Mississippi River, serving approximately 600,000 residents and providing a sanctuary for biodiversity in its wetlands. Two major concerns trouble the lake, trace metal (TM) pollution and Phragmites australis (P. australis). State agencies have invested time, effort, and resources to manage these issues, however, success has been limited. Although TMs are naturally occurring in the environment, they can be toxic at elevated levels. P. australis is a hardy, fast growing macrophyte that is adaptable and tolerant of poor soils. This allows the plant to spread rapidly through both healthy and polluted sites, out-competing native species. Due to P. australis resilience and aggressive nature, many colonies have grown around the lake regardless of soil conditions. Studies have shown that P. australis have been used to clean up lakes by removing TMs from sediment. While P. australis must be addressed; can it be used as part of the solution by identifying TM polluted areas? The purpose of this study is to determine the difference in TM uptake in P. australis in non-polluting and known polluting sites in the wetlands surrounding hypereutrophic Utah Lake. Nine sites around Utah Lake were selected, each based on land use type and distance from non-active and active or historic polluting sites. Three replicate samples of P. australis and soil were collected, washed, weighed, ground, sieved, acid digested, and analyzed for TM content using the ICP-OES. Water samples were taken when applicable. Statistical analysis was done using R Studio and Microsoft Excel. Results show TM concentrations in soil (and plants) were highest in polluted sites vs non-polluted sites. For example, a polluted site had a concentration of 39.8 PPM of cadmium, while a non-polluted site had a concentration of 0.89 PPM. In select sites, P. australis was found to hyperaccumulate arsenic 167.14% more than the background concentration of 7.2 PPM. For arsenic, the transfer factor for polluted vs non-polluted sites was approximately 60% and 10%, respectively. The transfer factor may indicate that P. australis may be used as a biomarker. This research is relevant as it may provide a way for state agencies to locate polluted sites and implement policies to help manage Utah Lake as it relates to trace metal pollution.