Nutrient cycling and methane production
A recent study (pdf, 3.7 MB) indicates that the CH production in Lake Kivu has significantly increased in the past three decades. This increase could have been generated by changes in the nutrient cycling of the lake due to the fast-growing population in its catchment. But also the introduction of Limnothrissa miodon, a pelagic and planktivore fish in Lake Kivu, could be responsible for significant changes in the nutrient fluxes.
This Ph.D. project (research plan, pdf, 793 KB) examines the cycles of P and N in the lake. In particular, the external nutrient sources, their internal fluxes and sedimentation are quantified. The methane production, its oxidation and the methanotrophic bacteria are investigated. A one-dimensional numerical model of Lake Kivu brings together the methane production and the nutrient cycling. The model is a powerful tool for decision-makers, as it is able to predict the future development of the methane reservoir based on different strategies to limit eutrophication and to exploit the methane. As such, the scientific findings may assure a more sustainable management of the lake in the future.
In
addition, this project builds research capacities in Rwanda and Congo
and provides a continuous scientific exchange, which is required for
the monitoring of the lake to prevent a gas outburst.
Contact person
Funding
First results:
- Pasche N., Dinkel C., Müller B., Schmid M., Wüest A., Wehrli B. (2009) Physical and biogeochemical limits to internal nutrient loading of meromictic Lake Kivu. Limnology and Oceanography, 54(6), 2009, 1863–1873 [pdf, 1.42MB]
- F. A. Muvundja, N. Pasche, F.W.B. Bugenyi, M. Isumbisho, B. Müller, J.-N. Namugize, P. Rinta, M. Schmid, R. Stierli, A. Wüest (2009) Balancing Nutrient Inputs to Lake Kivu. paper submitted [abstract: pdf, 65KB]
- N. Pasche, M. Schmid, F. Vazquez, C. Schubert, A. Wüest, J. Kessler, M. Pack, B. Reeburgh, H. Bürgmann (2010a) Methane sources and sinks in Lake Kivu. paper submitted [abstract: pdf, 24KB]
- N. Pasche, G. Alunga, K. Mills, F. Muvundja, D. B. Ryves, M. Schurter, B. Wehrli, M. Schmid (2010b) Abrupt onset of carbonate deposition in Lake Kivu during the 1960s: response to food web alteration and hydrological change. paper submitted [abstract: pdf, 17KB]