Biogeosciences, 18, 4369–4388, 2021 https://doi.org/10.5194/bg-18-4369-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Carbon sources of benthic fauna in temperate lakes across multiple trophic states Annika Fiskal1, Eva Anthamatten1, Longhui Deng1, Xingguo Han1, Lorenzo Lagostina1, Anja Michel1, Rong Zhu1, Nathalie Dubois2,3, Carsten J. Schubert1,4, Stefano M. Bernasconi3, and Mark A. Lever1 1Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, Universitätstrasse 16, 8092 Zurich, Switzerland 2Department Surface Waters – Research and Management, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland 3Department of Earth Sciences, ETH Zurich, Sonneggstrasse 5, 8092 Zurich, Switzerland 4Department of Surface Waters – Research and Management, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Seestrasse 79, 6047 Kastanienbaum, Switzerland Correspondence: Annika Fiskal (annikafi
[email protected]) and Mark A. Lever (
[email protected]) Received: 26 August 2020 – Discussion started: 11 September 2020 Revised: 2 June 2021 – Accepted: 21 June 2021 – Published: 28 July 2021 Abstract. Previous studies have shown that microbially pro- in so far uncharacterized relationships with detrital organic- duced methane can be a dominant carbon source of lacus- matter-degrading bacterial endosymbionts. trine sedimentary macrofauna in eutrophic lakes, most likely through grazing on methane-oxidizing bacteria. Here we in- vestigate the contributions of different carbon sources to macrofaunal biomass across five lakes in central Switzerland 1 Introduction that range from oligotrophic to highly eutrophic. Macrofau- nal communities change with trophic state, with chironomid Lake sediments are globally important organic C sinks (Ein- larvae dominating oligotrophic and tubificid oligochaetes sele et al., 2001; Mendonça et al., 2017) and sources of dominating eutrophic lake sediments.