The goal of this research project was to reconstruct:
- the history of cyanobacterial blooms
- the occurrence of toxic genes from lake sediments
- the effects of cyanobacteria on locally adapted zooplankton
in the Danube Delta. Knowledge about this history is crucial to predict the risk for harmful cyanobacterial blooms in the context of environmental change and their consequences for lake food webs.
The formerly hyper-eutrophied lake Greifensee, Switzerland, was an ideal study site to develop the method to reconstruct cyanobacterial blooms from sediment cores: historical data were available for zoo- and phytoplankton and for the population structure of the waterflea Daphnia. This is a key organism in aquatic food webs as it eats the algae and serves as fish food.