METALS, NUTRIENTS, AND RESTORATION: UNRAVELING THE FUTURE OF THE UPPER CLARK FORK RIVER, MONTANA

The Upper Clark Fork River (UCFR) has a long history of contamination, including a flood in 1908 where mine tailings containing heavy metals were distributed across the channel and floodplain. In 2013, a US EPA “superfund” (CERCLA) decision led to planning the substantial remediation of the river’s floodplain and vegetation, in efforts to mitigate the influence of heavy metal contamination on the ecosystem. This provided a unique opportunity to study the recovery of UCFR ecosystem as restoration continues. Broadly, we aim to learn how river ecosystem structure and function respond to the simultaneous influences of changing nutrient abundance and hydrologic connectivity due to large-scale floodplain restoration. We identified three goals (1) how restoration in the headwaters will alter the metabolic character of the aquatic ecosystem associated with enhanced periodic floodplain inundation, (2) use of geochemical approaches to address how river metals bind with dissolved organic carbon (DOC) molecules and influence its bioavailability to microbes and invertebrates, and (3) how restoration and changing nutrient availability influence biogeochemical and ecological gradients that extend downstream. We are working to integrate biological, chemical, and hydrological data to pinpoint the timing of nutrient delivery that influences longitudinal patterns seasonally and annually in the UCFR over five years. Further, we will identify the key drivers of DOC processes shaping UCFR's biogeochemical patterns, using a combination of quantitative and qualitative DOC measurements.

Presentation Preference: Poster

Primary Presenter: Arya Mohanan, University of North Texas, Denton, Texas 76201 USA (aryamohanan@my.unt.edu)

Authors:

Arya Mohanan, Department of Biological Sciences and the Advanced Environmental Research Institute, University of North Texas  (aryamohanan@my.unt.edu)

James R. Junker, Department of Biological Sciences and the Advanced Environmental Research Institute, University of North Texas, Denton, Texas, USA  (james.junker@unt.edu)

Marc Peipoch, Stroud Water Research Center  (mpeipoch@stroudcenter.org)

Robert Payn, Department of Land Resources and Environmental Sciences, Montana State University  (rpayn@montana.edu)

Michael D. DeGrandpre, Department of Chemistry and Biochemistry, University of Montana, Missoula, Montana 59812, USA  (michael.degrandpre@mso.umt.edu)

Juliana D’Andrilli, Department of Biological Sciences and the Advanced Environmental Research Institute, University of North Texas  (juliana.d'andrilli@unt.edu)