Shallow lake
Shallow lake

Effects of bioturbators in greenhouse gas emissions from shallow inland waters

2022 until 2026
Project member(s)
Prof. S. Kosten (Sarian) , I. Marquina Luévano (Ilenia) , Prof. Dr. Andreas Lorke (Institute for Environmental Sciences. University of Koblenz-Landau) , Dr. Dick van Oevelen (Royal Netherlands Institute for Sea Research. NIOZ- Yerseke. Yerseke)
Project type

Shallow freshwater bodies play a key role in the cycling of greenhouse gases (GHG), both as a carbon sink in their sediments and as a source to the atmosphere when saturated with carbon gases. The GHG dynamics in water and sediments are influenced by physical, chemical, and biological processes such as transport through the sediments, production, and consumption. Furthermore, bioturbators can alter these dynamics, for example by resuspending sediments, increasing the release of bubbles, or affecting benthic production and respiration. However, little is still known about these effects and their study requires combined approaches of empirical and experimental analysis. 

The overall aim of the project is to unravel the role of bioturbators on GHG emissions in shallow fresh waters under different scenarios (e.g.: temperature, sediments, bioturbators densities). To assess the bioturbator effect on gas bubble distribution and dynamics, monitor gas bubble formation and ebullition in the sediment will be visually monitored with below-sediment- scanners in mesocosms. To assess the bioturbator effect on gas transport rates, different functional traits will be measured. Here, sediment  oxygenation will be determined with vertical O2 profiles using an optode. Sediment reworking and bioturbation depth will be determined by vertical profiles of luminophores at the end of the experiment. Bio-irrigation will be assessed by adding NaCl to the surface water and following the decline of salinity in time. 

The functional traits will be measured under different conditions and experiments (mesocosm, microcosm, and flumes). Moreover, the bioturbator effects will be incorporated in a process‐based sediment‐water methane (CH4) emissions model. So far, quantitative knowledge on the impact of bioturbation on CH4 emissions is limited, as well as the application of mathematical models evaluating or predicting their effects.  This project will focus on CH4 and on processes that consume or produce CH4, as well as processes that are directly affected by consumers and producers of CH4.


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