Towards an Understanding of Dissolved Methane Dynamics in Streams
Project Summary:
Most freshwaters are sources of greenhouse gases, such as methane (CH4), to the atmosphere. However, much of the CH4 dynamics, including temporal patterns, sources, and isotopic composition remain unexplored, particularly in streams. Developing a mechanistic understanding of CH4 within running waters is critical to enhance our knowledge of these fluxes and improve our capacity to predict their future change. To better understand the processes controlling CH4 , Erin Hotchkiss and I quantified potential CH4 water column production rates and temporal changes in concentration and source variation during the 2018-2019 year. Results from these experiments were presented at the 2019 Dennis Dean Undergraduate Research and Creative Scholarship Conference. This research was supported by the Fralin Undergraduate Research Fellowship (FURF) program. |
Emerging contaminant effects on ecosystem function in freshwaters
Project Summary:
Ciprofloxacin is an antibiotic commonly found in freshwater streams and has been shown to negatively affect ecosystem respiration. Although some preliminary studies have been done, the effect on ecosystem functioning largely remains unknown. In the summer of 2018, AJ Reisinger and I compared the effect of this drug on stream biofilms with changing concentration and location relative to receiving waste water effluent. Results were presented at Rice University Undergraduate Research Symposium 2018 and the AGU 2018 Fall Meeting. Click to view the poster that was presented on this topic at AGU 2018 in Washington, DC. |
Greenhouse Gas Dynamics in Streams: Sources, Patterns, Processes
Project Summary:
Freshwaters are sources of greenhouse gases (GHGs) to the atmosphere. However, the spatial and temporal heterogeneity of GHG fluxes, and how they relate to land use, remains a major source of uncertainty in regional and global carbon budgets. To understand interactions between land use and GHG dynamics, Erin Hotchkiss and I measured CH4 and CO2 during the summer of 2017 in Stroubles Creek, a second-order stream in Virginia, which flows through three land use transitions (urban, agriculture, forest). Preliminary results show that sites draining more modified landscapes had higher concentrations of CH4 and CO2 than forested reaches. In addition, CH4 and CO2 were positively correlated with open/low-intensity urban land use, and negatively with forested and agricultural land use. A more critical look at the sources of methanogenesis in streams will be explored during Fall 2018. Click to view the poster that was presented on this topic at SFS 2018. |