Hi there, if you want to find which articles have already been published, you can find a complete and updated list on Google Scholar. If you are interested in my science outreach work, please visit my private Homepage, where you can learn about "The World of Hopfs" and other outreach projects. 
I am generally interested in the individual and population-level consequences of human-induced environmental changes and the functioning of coastal ecosystems.
My focus is on behavioral responses since they are the first and vital reactions to environmental change and thus need to be studied in plankton ecology. The distribution of behavioral differences between individuals in a population contains essential information for a mechanistic understanding of ecosystem functioning and for the potential of a species to cope with novel environmental challenges. Knowledge about individual differences and phenotypic plasticity of behavior is vital to predict the consequences of global change, such as temperature increases and ocean acidification, pharmaceuticals, and other anthropogenic contaminants.
In recent years, I studied the interaction of natural stressors (predation) and anthropogenic contaminants (copper) on the behavior, life history, and population dynamics of coastal copepods in the project MULTICOP.
I joined the POICE project last year, which investigates the role of parasites and disease in copepods. To study the hosts' temporal disease dynamics and potential behavior changes, we use high-throughput imaging devices such as CPICS and Planktoscopes. This is ongoing work, and I hope to share the results soon.
Much of my research also involves open-source and affordable imaging platforms. I have developed new experimental approaches using open-source hardware (Raspberry Pi, 3D printing). These include a device with which one can follow the growth of individual copepods over time and another to measure the size of live zooplankton in the field.