Selected publications

This study is an important step to establish the use of satellite imagery for inland water quality monitoring. By using in situ measurements of the algal pigment chlorophyll-a from small-sized lowland lakes in Northern Germany, we identified the best performing atmospheric correction and bio-optical algorithm to accurately estimate chlorophyll-a from Sentinel 2 satellite images. 

Climate change causes a decrease in the ice cover on lakes throughout the world. Yet, there has been insufficient research into how this decline of the winter period affects the interplay of phytoplankton and zooplankton. This study shows that even a gradual decline in the average duration of ice cover can result in abrupt changes in plankton dynamics.

The vertical flux of marine snow reduces atmospheric CO2. In particular, particle associated prokaryotes are responsible for organic C-loss. Analysis of prokaryotic heterotrophic production a. species richness in the North Atlantic reveal that C- loss a. associated microbial richness are different with particle fractions. Especially large, fast-sinking particles drive C-flux a. -sequestration.

This study investigated whether the microbial degradation of more refractory organic matter (OM) is stimulated by the addition of well available OM from dead zooplankton. A significantly higher respiration was measured when zooplankton-derived OM was added to ratio of 1:1. Stimulation was stronger in a complex microbial community with eukaryotes than just bacteria. 

Phaeocystis pouchetii regularly dominates Arctic marine plankton and is considered a key food source supporting highly productive fisheries. But the relevance of biomass transfer to higher trophic levels is debated. This study shows that endometabolic markers can be correlated to the metabolic state of Phaeocystis populations, which allows testing the influence on zooplankton trophic transfer.

The authors have shown that shifts in microbial communities triggered by chronic exposure to low concentrations of silver nanoparticles increases the community tolerance to silver, as described in the pollution-induced community tolerance (PICT) concept, with consequences for leaf litter decomposition, a pivotal process in forest streams. 

The neonicotinoid imidacloprid (IMI) is one of the most extensively applied neuro-active insecticides worldwide and continues to enter surface waters in many countries despite a recent ban for outdoor use in the EU. The study assessed the effects of pure IMI and its commercial formulation Confidor® on the aquatic oligochaete Lumbriculus variegatus, a key species in freshwater sediments.

The largest freshwater bacterium, Achromatium oxaliferum, is highly flexible in its requirements. The bacterial strains from the different ecosystems do not differ in their gene content, but rather choose what to express.