1. Diversity and composition of ecological communities
The main objective of the group is to study ecological communities. We focus mostly on freshwater macroinvertebrates. We apply wide variety of approaches (observational and experimental studies, meta-analyses and modelling) and focus on the causes and consequences of patterns in diversity and composition.

2. Human impacts on freshwater biodiversity
We examine the effects of human impacts on freshwater biodiversity. We focus on how the different facets (taxonomic, phylogenetic and functional) and components (alpha and beta) of diversity, as well as the taxonomic- and trait-based community respond to anthropogenic disturbances such as urbanization, pollution or habitat degradation.

3. Research into the success of invasive macroinvertebrates in Lake Balaton
We primarily follow the population dynamics of the invasive dreissenid species in the littoral zone of Lake Balaton at different trophic state. We examine the colonization, food preference and metabolism of the animals using experimental methods on animals collect from natural habitats, on implanted ones and on those kept in aquaria. Considering the role of dreissenids in the food chain of Lake Balaton, we carry out applied research into the use of them as feed in freshwater fish farming

4. Numerical ecology
We deal also with the methodology of community ecology. We are interested in approaches quantifying community-level phenomena such as beta diversity or nestedness, as well as in methodology enumerating functional diversity.

- Chemical characterization of aquatic environment (water body, sediment, phyto- and zooplankton, phyto-and zoobenthos, macrophyton, macro invertebrates, fish) with special attention to the exploration of pollution sources and identification and quantification of pollutants (e.g. pharmaceutical residues, microplastics)
- Monitoring of water quality in rivers and lakes complying with the requirement of the EU Water Framework Directives and database building to follow the changes of physical, chemical and biological parameters of Lake of Balaton as well as Duna and Tisza rivers
- Study of biofilm formation in aquatic environment focusing on the colonization of bacteria on different substrata and the role of their metabolites on the colonization of algae
- Effect of climate change on the nutrient turnover harmonizing with the analyses of biological parameters
- Effect of trace element-enriched or even highly contaminated irrigation waters on the plant cultivation through the soil-plant, plant-human nutrient connections
- Identification of infochemicals emitted by macro- and micro organisms into the freshwater environment applying modern analytical techniques
- Characterization of environmental condition of freshwater and revealing the relevance of the general toxicity of xenobiotics based on the ecotoxicological tests and environmental risk assessment
- Study of physiological effects of toxic materials in aquatic macro invertebrates and fish model organisms. Molecular processes accompanying adaptation to anthropogenic pollution in invertebrates and lower vertebrates

We examine the biodiversity and organization of freshwater fish assemblages.

Our primary model system are the Danube and Lake Balaton and its catchment, which is affected by a variety of human impacts. The primary focus is to explore the environmental drivers of population dynamics and assemblage organization, and, from an applied perspective, to provide suggestions for environmental managers and conservationists to mitigate human impacts. Specifically, we examine the habitat use, ontogenetic diet patterns, trophic relationships, growth, and survival of fish in Lake Balaton. The main task of the monitoring of the waterbasin’s streams is to follow the distribution of non-native invasive species and to explore their impact on the native fauna. We also examine the organization of fish assemblages in the River Danube and its floodplain system.

Increasing emphasis is given to the study of the diversity and distribution of fish in a regional (country-wide) scale to develop monitoring systems for evaluating environmental health, to base conservation planning actions and to explore the effects of human impacts on freshwater biodiversity in the Pannon Ecoregion.

A basic task of the team is the monitoring of the zooplankton and littoral invertebrate communities in several different standard sampling sites of Lake Balaton. This activity serves the continuous enlargement of the long term datasets concerning to the species composition, individual density, biomass and production of the zooplankton and macroinvertebrates dvelling the littoral zone. Collection of these data started in the early 1930`s making possible the analyses of the direct and indirect impacts of the anthropogenous eutrophycation, the long term fluctuation of the water lewel and the possible climate change on the invertebrate communities. The efficiency of the trophyc relationships between the phytoplankton – zooplankton, and macroinvertebrates – suspended material has been intensively studied in the frame of different research projects.