Department Surface Waters - Research and Management

Phytoplankton plays a central role in lakes. It forms the basis of the food chain for higher-order organisms. Its species composition and status are important indicators of the resilience of the ecosystem. Phytoplankton communities have characteristic pigmentation. These can be analysed using spectrometric measurements in the laboratory, in the field, from aircraft or satellites.

In the laboratory, phytoplankton cultures are often grown under artificial white light. In doing so, they form pigments that can differ considerably from those in naturally grown phytoplankton. We use an experimental device with which we can regulate light, temperature and nutrients during algae cultivation. This allows us to better understand the effects of changing environmental conditions on the pigmentation of selected phytoplankton taxa.

The spectral reflectance, i.e. the colour of lakes, is influenced by phytoplankton pigments, among other things. It can be easily measured with optical sensors. These measurements can be interpreted with the representative pigment absorption of suitable laboratory cultures. This allows us to analyse the occurrence and condition of different plankton species on a large scale. Following successful tests with ground-based measurements, we are now also applying this method to hyperspectral aircraft and satellite data.