EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

DOH! – The interface of isotope hydrology, ecology, and organic geochemistry

Travis Blake Meador1, Stanislav Jabinski1, Anna Mičanová2, Niclas Zehetner1, Karelys Umbria-Salinas1, Matthias Pilecky3, and Leonard Wassenaar3
Travis Blake Meador et al.
  • 1Biology Centre Czech Academy of Sciences, Czechia and University of South Bohemia, Faculty of Science, Czechia
  • 2Biology Centre Czech Academy of Sciences, Czechia and Gymnázium Český Krumlov
  • 3WasserCluster Lunz am See, Austria

Dissolved organic matter (DOM) cycling is essential to understanding energy flow in aquatic ecosystems and their role as a source or sink of CO2 in the global carbon cycle. Quantifying DOM turnover and reactivity have been confounded by the barely detectable changes in the molecular composition and 13C & 15N stable-isotope compositions. We hypothesized that significant seasonal isotopic changes in environmental waters and primary biological productivity might be reflected in the H & O stable-isotope composition of DOM, providing an alternative way to assess the accumulation, turnover, and transport of DOM in aquatic environments. H & O stable-isotope analyses of DOM from lakes showed temporal coupling of water isotopes with organic molecules that accumulate in natural aquatic environments, which varied between catchments and by molecular size components of DOM. An in-situ stable-isotope labelling (HDO) experiment revealed (microbial) turnover of DOM occurred on a weekly timescale. Further development of δ2H- and δ18O-DOM analyses may improve our understanding of the provenance and processing of DOM and help better constrain unknowns in the metabolic balance of inland waters.

How to cite: Meador, T. B., Jabinski, S., Mičanová, A., Zehetner, N., Umbria-Salinas, K., Pilecky, M., and Wassenaar, L.: DOH! – The interface of isotope hydrology, ecology, and organic geochemistry, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-17216,, 2023.