iUTAH Summer Research: Analyzing diel variations of MeHg in the Provo River, Utah

iUTAH is an interdisciplinary research program aimed at strengthening science for Utah's water future and funded by the National Science Foundation. iUTAH is comprised of three research areas with an overarching goal of understanding how Utah's water system operates as an integrated physical, chemical, biological, and social system. During the Summer of 2016, I participated in the iUTAH (Innovative Urban Transitions and Aridregion Hydro-sustainability) iFellows undergraduate research program. iUTAH provided the opportunity to conduct research at Brigham Young University with graduate students studying trace metal dynamics in the Provo River, Utah, USA. This report presents the chemical system evaluation of methylmercury (MeHg) during diurnal variations from snowmelt runoff. Water samples were collected during peak discharge from Soapstone Basin, a site along the Upper Provo River watershed, every hour over a 24-hour (diel) period. Sampling began at 1200 hours on June 1 and ended at 1100 hours on June 2, 2016. The results of the Provo River MeHg analysis showed dissolved MeHg had a concentration variance of 0.027 ng/L and particulate MeHg had a concentration variance of 0.056 ng/L. The variances during the diel cycle represent more than a two-fold change in concentration. The hourly MeHg concentration levels demonstrated an inverse relationship with gage height indicative of dilution. The purpose of the study is to develop a more thorough understanding of short-term variances over time and the potential affect on long-term interpretations of MeHg fluctuations in the river. The Provo River flows through Jordanelle Reservoir where there is a mercury advisory for two fish species. MeHg is a bioaccumulative neurotoxin that humans are primarily exposed to by the consumption of contaminated fish. The strong correlation between the levels of MeHg in water and fish make the river concentrations an important factor.