Project 1044
Chironomid 13C as a proxy of past methane emission from thermokarst lake sediments: development, calibration and applicationProject leader:
Prof. dr. A. F. LotterResearcher(s):
Dr. M. R. van HardenbroekStarting date: 1-jan-07
AbstractThermokarst lakes are an important source of atmospheric methane, especially now large areas of permafrost are thawing ( Walter et al. 2006, Walter et al. 2007). However, due to their remote location, time-series of methane emission from thermokarst lakes are rare and uncertainty exists regarding recent changes in methane fluxes form these lakes. We will explore the carbon isotopic composition of fossil chironomids as a novel proxy of past methane emission from thermokarst lake sediments in NE Siberia. Methanotrophic bacteria in lake sediments are an important food source for deposit-feeding chironomids. This leads to strongly negative 13C in chironomids if methane-derived carbon is a significant component of their diet. Chironomid exoskeletons preserve well in lake sediments and 13C can be measured on these fossils to reconstruct chironomid 13C in the past. We will use cultured chironomid larvae to initially develop the chironomid 13C methodology. Later, species-specific 13C measurements in fossils contained in lake surface sediments will be used to assess within-lake and inter-species variability in chironomid 13C. 13C of selected chironomids will be compared with methane flux measurements in a number of lakes to quantify the chironomid 13C-methane flux relationship. Finally, we will produce down-core records of past chironomid 13C to reconstruct recent trends in methane emission from thermokarst lake sediments in NE Siberia.
Publicationsvan Hardenbroek, M., Heiri, O., Grey, J., Bodelier, P.L.E., Verbruggen, F., Lotter, A.F.
(2009). Fossil chironomid δ13C as a proxy for past methanogenic contribution to benthic food webs in lakes?
. Journal of Paleolimnology1-11.
Darwin Center authors: Bodelier P. L. E., van Hardenbroek M. R., Lotter A. F., Verbruggen F.Maarten van Hardenbroek, Oliver Heiri and Andre F. Lotter (2010). Efficiency of different mesh sizes for isolating fossil chironomids for stable isotope and radiocarbon analyses. Journal of Paleolimnology44 (2): 721-729.
Darwin Center authors: van Hardenbroek M. R., Heiri O. M., Lotter A. F.Maarten van Hardenbroek (2010). Stable carbon isotopes of invertebrate remains : do they reveal past methane release from lakes?.
Darwin Center authors: van Hardenbroek M. R.M. van Hardenbroek • O. Heiri • M. F. Wilhelm • A. F. Lotter (2011). How representative are subfossil assemblages of Chironomidae
and common benthic invertebrates for the living fauna
of Lake De Waay, the Netherlands?. Aquatic Sciences73: 247-259.
Darwin Center authors: van Hardenbroek M. R., Heiri O. M., Lotter A. F.Van Hardenbroek, M. , Lotter, A. , Bastviken, D. , Duc, N. , Heiri, O. (2012). Relationship between δ13C of chironomid remains and methane flux in Swedish lakes. Freshwater BiologyVolume 57, Issue 1: 166-177.
Darwin Center authors: van Hardenbroek M. R., Heiri O. M., Lotter A. F.