Cyanobacteria dynamics under eutrophication and climate change

Eutrophication is still a large problem facing surface waters in Europe. Blooms of cyanobacteria choke out other aquatic life and produce toxins which endangers the safe production of drinking water, recreation and public health. The recent scientific literature forecasts that climate warming will increase these problems. A warmer climate will promote cyanobacterial blooms and threatens to undo decades of succesful lake restoration in Europe, where meausures to mitigate eutrophication and control cyanobacterial blooms have been taken at the expense of billions of euros. Yet there is no scientific consenus about the way eutrophication and climate change will interact. Some authors claim nutrients will remain the main cause of blooms and see only a minor role for temperature, while others predict climate warming will have a major impact ("blooms like it hot"). Important question: will nutrients and temperature interact synergistically? This is not only of scientific interest, it also determines which measures must be taken to prepare our ecosystems and control blooms in future. This proposal seeks to provide reliable answers on the question how the two stressors interact. We will do so by a three pronged approach: (i) paleolimnology (learning from climate change in the past), (ii) experiments under controlled conditions in chemostats, (iii) a multiple lake survey in all CyanoCOST countries, results to be used to construct a predictive cyanobacterial distribution model.