Ecological roles of fungal parasites on benthic diatoms in polar coastal waters

Are parasites unjustly unpopular? Fungi, such as chytrids, play an ecological key role as lethal parasites in the aquatic food web. Chytrids produce motile zoospores as their infective propagules, which they use to infect microalgae. Zoospores contain a high concentration of polyunsaturated fatty acids (PUFAs) and cholesterol and serve as a nutrient rich food source for zooplankton. Zooplankton thus benefits from the fungal infestation of algae. Therefore, chytrids play a significant role in upgrading of available organic matter/food, both in terms of quantity and nutritional quality. This makes them an important link in the food web. They can also redirect carbon through processes called: mycoloop, mycoflux, and fungal shunt.
Due to the increasing effects of global warming, polar aquatic ecosystems, especially coastal waters, are facing severe changes. This has been shown to affect microbial community structure. Thus, climate change can stimulate chytrid parasitism of benthic microalgae, or modify already existing parasite-host inter-relationships, consequently having a greater impact on the polar aquatic food web dynamics. To date, parasitism in the polar regions and in benthic habitats remains largely unstudied.

Research questions

  • How relevant are parasitic interactions in polar benthic diatoms?
  • How does climate change affect these interactions and thus host-parasite dynamics?
  • What strategies do chytrid parasites use to survive the harsh environmental conditions in polar regions?


  • Genomics
  • Transcriptomics
  • Microscopy
  • Metabolomics

Responsible persons

Prof. Dr. Hans-Peter Grossart, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) and University of Potsdam, Biochemistry and Biology

Doris Ilicic, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB)

Sampling of benthic biofilms in Kongsfjord, Svalbard, August 2022. Foto: Leibniz-Institute of Freshwater Ecology and Inland Fisheries

Projects we participate in

Ecological role of fungal parasites on benthic diatoms of polar coastal waters, SPP 1158 Antarctic Research

National Science Foundation Grant #OPP-1637708 for Long Term Ecological Research, McMurdo Dry Valleys