Ubiquitous and significant anaerobic oxidation of methane in freshwater lake sediments
Thalasso, Frederic
- 1
- 2CINVESTAV - Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional
- 3Leibniz Association
- 4University of Alaska System
- 5Skidmore College
Journal
Water Research
ISSN
0043-1354
Open Access
closed
Volume
144
Start page
332
End page
340
Anaerobic oxidation of methane (AOM) is a microbial process that consumes dissolved methane (CH4) in anoxic sediments and soils and mitigates CH4 release to the atmosphere. The degree to which AOM limits global biospheric CH4 emissions is not fully understood. In marine sediments, where the process was first described, AOM is responsible for oxidizing >90% of the CH4 produced. More recently, AOM has been observed in soils, peatlands, and freshwater ecosystems. In lakes, where sediment anoxia, organic carbon turnover, and CH4 production are common, AOM is not well studied but could represent a significant CH4 sink and constraint on emissions. Here, we present evidence for the occurrence of AOM in the sediment of thirteen lakes that span a global climatic and trophic gradient. We further quantified and modeled AOM patterns and studied potential microbial controls of AOM using laboratory incubations of sediment and stable isotope measurements in three of the thirteen lakes. We demonstrate that AOM is widespread in freshwater lake sediments and accounts for 29%-34% (95% confidence interval) of the mean total CH4 produced in surface and near-surface lake sediments. (C) 2018 Elsevier Ltd. All rights reserved.