Crayfish once inhabited the streams of the Sihlwald, but today they are no longer found there. Functioning ecosystems are crucial for biodiversity and adaptation to climate change. Crayfish are part of that. Studies have now shown that some streams in the Sihlwald offer optimal living conditions for crayfish.
The Project
The Zurich Wilderness Park, in collaboration with“Lebensgemeinschaft Wasser Schweiz,” plans to reintroduce crayfish to the Sihlwald. In addition, interactive exhibits are planned for the aquarium on the grounds of the visitor center. These are intended to educate children and adults about native aquatic life and raise awareness about its protection.
The Friends of the Zurich Wilderness Park support this project. Various member events are planned as part of the project.
CHF 120,000 has been raised. Thank you very much!
- Reintroduction of crayfish in the Tomenrainbach Stream in the Sihlwald
- Promoting Biodiversity
- Raising awareness among visitors and the general public
- 2024: Permits and planning, initial reintroduction of crayfish, and public outreach
- 2025: Design of educational components
- 2026: Implementation of educational components, expansion of the aquarium lobby
- 2025–2027: Phasedreintroduction
- 2028: Evaluation of results
On September 21, 2024, the first 40 animals were released into the wild. More on this
On October 3, 2025, another 75 animals were released. The final population will be released in the fall of 2026.
"Crabs in the Crab Basket"
The Friends of the Zurich Wilderness Park are bringing crayfish back to the Sihlwald.
Crayfish play an important role in aquatic ecosystems as “nature’s cleaners” and are to be reintroduced into the Sihlwald.
