New Ecosystem Models

20 February 2025

Photo: Luisa Listmann

A project on phytoplankton funded by the PIER PLUS Seed Fund is now contributing to the improvement of marine ecosystem models – the project focused on the role of marine viruses and their behavior under rising temperatures.

Phytoplankton – small plant organisms in water ecosystems – produce, depending on the source, at least half of the world's oxygen. At the basis of the food chain, phytoplankton is highly relevant for the entire marine ecosystem. Phytoplankton is also the research focus of marine biologist Dr Luisa Listmann from the University of Hamburg and her colleague Dr Jana Hinners from the Helmholtz-Zentrum Hereon: specifically, the two researchers have investigated the effects of marine viruses on ecosystem dynamics in the Baltic Sea and how rising temperatures due to the climate crisis contribute to this. The researchers have published their findings in the journal Ecological Modelling. Their research was funded by the PIER PLUS Seed Fund.

Complex interactions

“Our model has shown that the warming of the water intensifies the viruses’ effects – phytoplankton is more susceptible to infection and dies off, which means less food for zooplankton and ultimately for fish, and the oxygen cycle also suffers,” explains Dr Luisa Listmann. Her research demonstrates the importance of the interaction between warming and virus activity: “The dynamics of viruses should definitely be included in future marine ecosystem models in order to be able to make reliable predictions about the effects of climate change.” Listmann is currently involved in a project on phytoplankton in the Elbe river. “We are now in the process of grasping and studying the complexity of these systems, with more powerful modelling options and new experimental designs – in other words, we are not reinventing the wheel, but detailed knowledge is increasing and we are still at the beginning when it comes to understanding viruses and their role in the ecosystem,” emphasizes the researcher.

The PIER PLUS Seed Fund support was very helpful for Listmann and Hinners, especially at the beginning, as Luisa Listmann emphasizes: “Firstly, it gave us an easy opportunity to submit and collaborate together. We were also able to hire student assistants who helped both with my experiments and Jana Hinners' modelling. Generally speaking, such collaborations are very rewarding because we brought both our expertise together and complemented each other well from a methodological perspective.” The aim of the PIER PLUS Seed Fund is the inter-institutional preparation of joint research proposals.