McCormick, Wegter Publish in Limnology and Oceanography
“Water column and sediment stable carbon isotope biogeochemistry of permanently redox stratified Fayetteville Green Lake, New York, U.S.A.” presents the results of a three-year study of carbon cycling and water chemistry in Green Lake, located 30 miles east of the Hamilton campus.
The lake is meromictic, meaning that it is comprised of two layers that never mix. Meromictic lakes are quite rare, numbering less than 800 globally. The lack of mixing results in starkly different chemistry (and associated microbial communities) in the upper and lower bodies of water.
Of particular interest in this study was the production and fate of methane, an important greenhouse gas, in the bottom waters of Green Lake. The study shows that this methane is remarkably enriched in isotopically light carbon, an indication that the carbon has been recycled (consumed and produced) many times by the lake’s microorganisms.
The findings have implications for our understanding of carbon cycling in Earth’s early oceans, which are also thought to have been stratified. The findings may also indicate how other freshwater lakes could respond to increasing periods of seasonal stratification, a problem that is exacerbated by nutrient run off from human land use and regional warming due to global climate change.
McCormick and Wegter conducted this study with colleagues from Penn State University and the University of Minnesota.