Switzerland is not supplied with sufficient amounts of protein for feed production, but has to import the main proportion from other countries. Duckweed can show high growth rates and protein contents on diluted manure and can reach production rates per squaremeter which are comparable to commonly used terrestrial plants. However the harvest of duckweed is time consuming and this leads to the need of an automatic concept for their culture.The project will clarify how high production efficiency and biosafety of a duckweed culture can be guaranteed and if fish can be sucessfully fed with duckweed. The feeding trials will be conducted with different fish species.