Limnology and Oceanography Page 2 of 48 This document is the accepted manuscript version of the following article: Steinsberger, T., Schwefel, R., Wüest, A., & Müller, B. (2020). Hypolimnetic oxygen depletion rates in deep lakes: effects of trophic state and organic matter accumulation. Limnology and Oceanography. https:// doi.org/10.1002/lno.11578 1 Hypolimnetic oxygen depletion rates in deep lakes: 2 Effects of trophic state and organic matter accumulation 3 4 Thomas Steinsberger1*, Robert Schwefel2,3, Alfred Wüest1,3, Beat Müller1 5 6 1 Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-6047 Kastanienbaum, Switzerland 7 2 UC Santa Barbara, 3015 Marine Science Building, Santa Barbara, CA 93106-6150, US. 8 3 Physics of Aquatic Systems Laboratory, Margaretha Kamprad Chair, École Polytechnique Fédérale de Lausanne, 9 Institute of Environmental Engineering, Lausanne, Switzerland. 10 11 ORCID: Thomas Steinsberger: 0000-0002-0751-5424; Robert Schwefel: 0000-0003-1610-4181; Beat Müller: 0000- 12 0003-3696-9035; Alfred Wüest: 0000-0001-7984-0368 13 Author Email address: 14 * Corresponding Author: Thomas Steinsberger:
[email protected] 15 Robert Schwefel:
[email protected] 16 Alfred Wüest:
[email protected] 17 Beat Müller :
[email protected] 18 19 Running Head: Hypolimnetic O2 depletion in deep lakes 20 Keywords : Carbon Mineralization, Porewater, Oxygen depletion, deep lakes, lake phosphorous, water column, 21 sediment 22 1 Page 3 of 48 Limnology and Oceanography 23 Abstract 24 This study investigated the consumption of oxygen (O2) in eleven European lakes ranging from 48 25 m to 372 m deep. In lakes less than ~100 m deep, the main pathways for O2 consumption were 26 organic matter (OM) mineralization at the sediment surface and oxidation of reduced compounds 27 diffusing up from the sediment.