Research activities

Since 1996 the Laboratory of Protistology and Aquatic Ecology (PAE) has been involved in research on the functioning and evolution of freshwater and marine ecosystems, with a strong focus on autotrophic unicellular eukaryotes (protists).

A central research theme is to understand the consequences of environmental and climate change for aquatic protist communities, together with additional influence of dispersal between local communities and their interaction. Traditional field-based approaches are complemented with ecophysiological, molecular and genetic studies of laboratory cultures, and microcosm experiments. The main focus lies on (1) phytoplankton communities and the microbial food web in shallow lakes in western Europe, (2) micro-algal communities in the Scheldt estuary (Belgium) and (3) benthic diatom communities on a global scale (directed towards the Southern Hemisphere). Based on these findings, Belgian lake management and restoration is guided. Protist remains, fossil DNA and biogeochemical markers in lake-sediment cores are also used to (quantitatively) reconstruct past climate and environmental change in the Southern Hemisphere (e.g., Antarctica, Chile and Tasmania).

In addition to community-level approaches, studies at the population- and organismal level integrate molecular biology, genetics and genomics with traditional biology (life-cycle, ecophysiology, morphology), thereby valorising our expertise regarding strain isolation and experimental manipulation. This way, the population structure and divergence of several model species of micro-algae are determined and experimental evolution is applied to study the underlying processes (dispersal, priority effects, selection,...). Another major research focus lies on the life- and cell-cycles, evolution and diversity of diatoms. More specifically, the evolution of mating systems and sexual behaviour is addressed. Also, cryptic variation and the evolution of reproductive barriers between closely related species and its consequences for our understanding of global diatom species diversity, biogeography and ecology are studied. Finally, genetic mechanisms underlying key changes in the cell- and life-cycle of diatoms are identified.

PAE coordinates or participates in multidisciplinary research in the framework of national and international research projects. Relevant topics in the context of Aquaculture are toxic bloom dynamics (Pseudo-Nitzschia, Microcystis), productivity and stability of protist communities (e.g. productivity-diversity relationships), ecophysiology (e.g. mixotrophy, salinity tolerance,..), and the genetic regulation of cell and life cycle (in particular of diatoms). For its research, PAE harbours an extensive research collection of living diatoms, which forms part of the Belgian Coordinated Culture collections of Microorganisms and is being used in collaborations with academic and industrial partners for respectively integrated biological and evolutionary studies and for aquaculture and biotechnological purposes.