Dr. Mona Schweizer
+49 7071 29 78818
fax: +49 7071 29 35299
room 019, basement floor
University of Tuebingen
Institute of Evolution and Ecology
Auf der Morgenstelle 5
During my PhD, I was working on the toxicity exerted by samples of different complexity on early life stages of fish and amphibians. In a first step, I studied the sublethal endpoint heart rate of zebrafish (Danio rerio) embryos in dependence of temperature to discriminate between substance and temperature effects. Subsequently, I was exposing zebrafish embryos in a fish embryo test (FET) to the pure compound glyphosate. In this case, the sublethal effects of glyphosate itself and the lethal effects of the glyphosate induced pH decrease could be distinguished. As substances are usually applied and introduced into the environment as formulations, I also tested the effect of the Bti (Bacillus thuringiensis israelensis) formulation VectoBac® WG on European common frog (Rana temporaria) tadpoles. Bti is a mosquito larvicide and used as an ecologically sensitive alternative for conventional insecticides and was suspected to directly impact tadpole health. Histological examination of tadpole intestines and biomarker analyses (Hsp70, AChE and b-esterases) invalidated the suspicion; no effects on tadpole health were detected. Finally, I investigated the toxicity organisms experience in the field using environmental samples. This work was embedded in the joint project NiddaMan (www.niddaman.de), which investigated anthropological influences, including communal and industrial wastewater and agricultural emissions, on a river system in Hesse, Germany. My work mainly focused on the FET with Danio rerio with water and sediment samples from the Nidda, Horloff and Usa rivers and emphasised, once more, the importance of sediments in environmental health evaluations of aquatic systems.
In my Post-Doc. studies, I now focus on basic research of pH-dependent toxicity of ionisable substances. Usually, ecotoxicological tests for environmental impact assessments are conducted at one (neutral) pH, but in nature pH varies and thus, the toxicity ionisable substances may induce nay vary accordingly. In the project PHION, in collaboration with the German Environment Agency (Umweltbundesamt, UBA) and University of Athens, we aim to develop a model that is capable to predict the change in toxicity dependent on the shift in pH. My responsibility mainly lies in generating toxicity data based on the FET with Danio rerio which is going to be conducted for about 30 different substances. Additionally, colleagues from the University of Athens analyse the bioaccumulation of those substances to substantiate the model and to identify the lethal body burden. Finally, the successful development of the PHION model will support the UBA in the approval process of new and re-evaluated ionisable substances, before introduced into the environment.
List of publications
- Geue, J. C., Vágási, C. I., Schweizer, M., Pap, P. L. and Thomassen, H. A. (2016). ”Environmental selection is a main driver of divergence in house sparrows (Passer domesticus) in Romania and Bulgaria.” Ecology and Evolution 6(22): 7954-7964. DOI: 10.1002/ece3.2509.
- Schweizer, M., Dieterich, A., Triebskorn, R. and Köhler, H.-R. (2017). ”Drifting away from a FET endpoint: the heart rate in Danio rerio embryos is extremely sensitive to variation in ambient temperature.“ Bulletin of Environmental Contamination and Toxicology 99(6): 684-689. DOI: 10.1007/s00128-017-2196-1.
- Schweizer, M., Dieterich, A., Corral Morillas, N. Dewald, C., Miksch, L. Nelson, S., Wick, A., Triebskorn, R. and Köhler, H.-R. (2018). “The importance of sediments in ecological quality assessment of stream headwaters: embryotoxicity along the Nidda River and its tributaries in Central Hesse, Germany.“ Environmental Sciences Europe 30(1): 22. DOI: 10.1186/s12302-018-0150-4.
- Dieterich, A., Schweizer, M., Betz, S., Prozmann, V., Triebskorn, R. and Köhler, H.-R. (2018). “Fischgesundheit an der Nidda.“ Korrespondenz Wasserwirtschaft (5): 272-281.
- Schweizer, M., Miksch, L., Köhler, H.-R. and Triebskorn, R. (2019). "Does Bti (Bacillus thuringiensis var. israelensis) affect Rana temporaria tadpoles?" Ecotoxicology and Environmental Safety 181: 121-129. DOI: 10.1016/j.ecoenv.2019.05.080.
- Schweizer, M., Brilisauer, K., Triebskorn, R., Forchhammer, K. and Köhler, H.-R. (2019). “How glyphosate and its induced pH decrease affect early development in zebrafish (Danio rerio).” PeerJ 7: e7094. DOI: 10.7717/peerj.7094.
- Schweizer, M., Triebskorn, R. and Köhler, H.-R. (2019). “Snails in the sun: strategies of terrestrial gastropods to cope with hot and dry conditions.” Ecology and Evolution (accepted). DOI: 10.1002/ece3.5607.