by Josh Appert, Lukas Götz, Simon Rüegg, Gwendolyn Wiesner
Lake Zurich has been undoubtedly shaped by human activity. Urban densification, large-scale shoreline construction in the 19th century, and the expansion of transport infrastructure in the 20th century have intensified interactions between the lake and the city of Zürich. At the same time, Lake Zurich is a vital ecological system and a major drinking-water source, making its environmental condition highly relevant for both humans and nature.
Urbanization influences the lake through multiple pathways. Thermal use of lake water, wastewater discharge, and agricultural nutrient inputs have altered physical and chemical conditions. Together with climate change, these pressures have led to rising water temperatures and modified mixing regimes. Such changes affect aquatic ecosystems through the food web: Cold- and oxygen-dependent fish species face shrinking habitats, while more tolerant species may gain advantages, reshaping species’ composition over time.
Our blog examines long-term trends in temperature, phosphorus, and oxygen in Lake Zurich and relates them to observed changes in fish populations. We also considered the historical development of water protection and fisheries legislation. Lake Zurich thus illustrates how urban development, environmental policy, and ecological processes intertwine in different ways. What this means for the lake’s future—and for managing urban lakes more broadly—becomes clearer when looking at the full story.
For a full examination of the nexus of urbanization and lake Zurich, take a look at the in-depth blog post that we produced in the context of the Geography. Matters. module at the Department of Geography in the fall semester of 2025.
About GEO410
This blog post is part of the outcome of an interdisciplinary Master’s-level course in Geography: GEO410 Geography. Matters. The course aims to bring together diverse geographic research perspectives to engage with some of the most pressing societal and environmental challenges of our time. As the only compulsory module of the Geography MSc program, the course encourages students to think across sub-disciplines of geography and to explore how geographic research can meaningfully contribute to debates around sustainability, justice, and environmental change.
Beyond conducting interdisciplinary research as a team, a central aim of the course was to experiment with creative and accessible forms of science communication. Rather than producing a purely academic output, students translated their research insights into blogposts, intended for a wider, non-specialist audience. The contributions thus showcase not only rigorous scientific work by highly motivated students, but also the importance of communicating research beyond the university and engaging broader publics in conversations about geography, sustainability and the future of our shared environments.
The students in the course GEO410 were supervised by Andreas Vieli, Christian Berndt and Sofia van Moorsel as lecturers and by Nikolas Klaudy as teaching assistant.
Beitragsbild: Final «Seegfrörni» of lake Zurich in 1963, in which the entire lake was frozen. Image: Comet Photo AG (Zürich)