Methane is an important greenhouse gas, and lakes and reservoirs account for roughly 10% of methane flux to the atmosphere globally. The contribution of aquatic sediments to atmospheric methane would be much greater if it were not for methane oxidation, the microbial process whereby methane is converted to CO2, a much more soluble, less potent greenhouse gas. A paper just out in Biogeochemistry by Dan Reed, Bridget Deemer, Sigrid Van Grinsven, and John Harrison, titled Are elusive anaerobic pathways key methane sinks in eutrophic lakes and reservoirs? provides new insight into this critical biogeochemical process. In the paper, Reed et al. show that concentrations of typical inorganic electron acceptors (compounds like oxygen, nitrate, and sulfate) are often insufficient to support observed rates of methane oxidation. To resolve this issue, we postulate that organic matter can serve as an important, though often-ignored, alternative electron acceptor in lakes and reservoirs, fueling high rates of methane oxidation, and urge the broader community to directly test this hypothesis.
PhD student Sofia D’Ambrosio won an award for her poster on methane emissions from reservoirs at the WSU Vancouver Research Showcase. Congratulations Sofia!
Undergraduate research assistant Terryn Mitchell has been awarded a highly competitive National Science Foundation Research Experience for Undergraduates fellowship to work with the Global Change and Watershed Biogeochemistry group this summer. Congraulations Terryn!!
John will participate as a U.S. delegate and lead author in the United Nations Intergovernmental Panel on Climate Change’s upcoming effort to update how countries account for their greenhouse gas emissions. Until recently, national greenhouse gas inventories have not included emissions from reservoirs, but recent work from our group and others has shown that this is a substantial oversight. In an effort to correct this, the UN has commissioned a chapter of their revised guidance to the national inventory development process focused on reservoirs. The first meeting for lead authors will occur in Bilbao Spain in June.
PhD student Corey Ruder has been selected as a 2017-2018 Luce Scholar – Congratulations Corey!
WSU Vancouver’s office of Research has funded several exciting research infrastructure proposals that will directly and indirectly support environmental research on our campus. These include: 1) a core facility in Environmental Mapping, 2) a research vehicle, and 3) improved high-performance computing access. The Environmental Mapping core facility will include a bathymetric system and a hyperspectral camera for airborne deployment. A fourth proposal to purchase equipment in support of cell and molecular research was also funded.
In a new study of six Pacific Northwest reservoirs (available via open access here) we document substantial increases in emissions of methane, a powerful
greenhouse gas, during drawdowns for power generation, flood control, irrigation, and maintenance.
We saw at least a three-fold increase in methane emissions via bubbling and diffusion during drawdowns. In Lacamas Lake, one of the study reservoirs, emissions surged more than 6,000-fold.
We also did a side-by-side comparison of two similar reservoirs and saw that the one with drawdowns released three times more methane than a reservoir located just upstream where water levels were held constant.
A related study released last year, led by Harrison Lab alum Bridget Deemer, found that, collectively, the world’s reservoirs have a greater greenhouse warming impact than all of Canada. The new study suggests steps that might be taken to reduce methane emissions from reservoirs such as timing drawdowns to follow periods when lake oxygen levels could help facilitate the breakdown of methane. It also raises questions regarding whether reservoir drawdowns have been sufficiently considered in recent efforts to estimate methane emissions from reservoirs.
The M.J. Murdock Charitable Trust has generously offered to provide $171,500 toward the purchase of two analytical instruments that together will greatly expand WSU Vancouver’s analytical capabilities: an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and an Ion Chromatograph (IC). We are optimistic that these instruments will be available to researchers on a fee basis beginning early in 2017 — stay tuned for more information. In the meantime, we are very excited about the potential to use these instruments to characterize water quality, elemental transfers, and biogeochemical transformations!