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Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
When species disappear from rivers and lakes – can they return one day? Prof Dr Sonja C. Jähnig is investigating this question. She is researching how damaged freshwater ecosystems can recover and regain their biodiversity, and the importance of healthy water bodies for our well-being. This brings things full circle for the newly appointed professor at the University of Duisburg-Essen: she had already completed her undergraduate studies and her doctorate here.
[Dr Alexandra Nießen:] How would you summarize your research in a few sentences?
[Prof Dr Sonja C. Jähnig:] I study how rivers, lakes, and other freshwater ecosystems are changing under the influence of global change – and how we can better protect and restore their biodiversity. I’m interested in what these changes mean for us as humans. Healthy water bodies provide clean water, protect against flooding, offer food and recreational spaces, and hold great cultural and emotional significance for many people. My research therefore combines biodiversity research with issues related to human health and social well-being.
What issues are particularly important to you?
What’s particularly important to me is how we can shift our focus from simply documenting biodiversity loss to better understanding how to restore it: Where do restoration measures work, where don’t they – and why? In this context, I’m interested in large freshwater animals (sturgeon, salmon, or beavers), for example, because they can have a major impact on ecosystems, but also in the importance of land-water interfaces and the connectivity of rivers and floodplains.
I am also deeply interested in the relationship between people and water bodies. We often view biodiversity primarily through a natural science lens. However, species and water bodies are also important to us culturally, emotionally, and in terms of our health. I want to understand how such relationships can contribute to the protection of biodiversity – and how healthy and diverse water bodies promote human well-being.
What are your plans at the UDE?
At the UDE, I would like to establish research on ecosystem health (“Freshwater Ecosystem Health”) and closely integrate three areas: the dynamics of changes in biodiversity, the contributions of aquatic ecosystems to human well-being, and the cultural and health dimensions of biodiversity.
Here’s an example: I will investigate where restoration can be particularly effective and what role the interfaces between water bodies and land play. Another focus will be on large freshwater species and non-native species. At the same time, I would like to systematically reassess the cultural significance of freshwater species and ecosystems.
At the UDE and within the RC One Health Ruhr at the Ruhr University Alliance, I am able to bring together expertise from the fields of aquatic ecology, microbiology, ecotoxicology, and neuroscience. I also plan to collaborate with the social sciences, for example on perceptions of biodiversity and societal acceptance of restoration.
Why did you choose the UDE?
What particularly impressed me was the opportunity to combine “traditional” biodiversity and ecosystem research with new perspectives on human health and societal well-being. The RC One Health Ruhr offers an exceptionally interdisciplinary environment for this.
At the same time, the UDE has a very strong and broad-based program in aquatic research – ranging from microorganisms to ecotoxicology and biodiversity, all the way to the study of entire river basins. This is ideal for me: Many of the major challenges of our time cannot be solved within a single discipline. If we want to understand what makes river restoration successful, we must consider not only species and ecological processes, but also water quality, pollutants, human use, and, ultimately, people themselves.
What should your students know about you?
I try to make my teaching as interactive as possible – with discussions, student-led projects, data analysis, and field trips. In ecology in particular, I find the connection between theory, data, and field observations to be especially important. Students should not only learn facts, but also develop scientific thinking and the ability to work independently. I see this as helpful for whatever comes after college. For me, that also includes skills such as critical thinking, data analysis, scientific communication, and teamwork.
I also encourage students to take advantage of the opportunities available to them, such as study abroad programs, scholarships, or independent projects. I have benefited greatly from these myself.
Having spent nearly 13 years at a Leibniz Institute, I believe it is important to apply research to real-world situations. For me, this involves, for example, international biodiversity initiatives and conservation organizations – whether it’s protecting migratory freshwater fish or addressing how freshwater biodiversity can be more fully integrated into international biodiversity and One Health debates.
Profile: Sonja C. Jähnig
• Since October 2026: Professor of Freshwater Ecosystem Health, University of Duisburg-Essen (UDE) and University Alliance Ruhr, Research Center One Health Ruhr
• 2025–2026: Acting Director of the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin
• 2022–2026: Head of the Department of Community and Ecosystem Ecology, IGB
• 2020–2026: Professor of Aquatic Ecogeography, Humboldt-Universität zu Berlin
• 2014–2026: Research Group Leader, IGB
• 2010–2013: Junior Research Group Leader, Biodiversity and Climate Research Centre (BiK-F), Senckenberg Society for Nature Research, Frankfurt am Main
• 2009: Postdoctoral Researcher, Department of River Ecology and Conservation, Senckenberg Society for Nature Research
• 2008: Postdoctoral Researcher, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China,
Young Scientists Award, Centre for Water and Environmental Research (ZWU), UDE
• 2007: PhD, Department of Applied Zoology and Hydrobiology, UDE
• 2001–2003: DAAD Scholarship, "Language & Professional Experience in China"
• 2001: Diploma in Environmental Sciences, UDE
Prof Dr rer. nat. Sonja C. Jähnig, UA Ruhr, RC One Health Ruhr, Freshwater Ecosystem Health, phone. +49 (0)201 183-3350, sonja.jaehnig@uni-due.de
Prof. Dr. Sonja C. Jähnig
Source: Alexandra Roth
Copyright: UDE
Criteria of this press release:
Journalists, Scientists and scholars
Biology, Environment / ecology, Oceanology / climate
transregional, national
Personnel announcements
English
Prof. Dr. Sonja C. Jähnig
Source: Alexandra Roth
Copyright: UDE
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