The Institute of Biological Research Cluj, branch of the National Institute of Research and Development for Biological Sciences (INCDSB), Bucharest, as Beneficiary, announces the completion of the project “Predictive food web models for aquatic ecosystems” – PredAqua, project code CF 72/14.11.2021, Funding Contract no. 760102/23.05.2023, implemented between 1 July 2024 and 30 June 2026, over a period of 24 months.

      The project was funded through Romania’s National Recovery and Resilience Plan (PNRR), Component C9 – Support for the Private Sector, Research, Development and Innovation, Investment I8 – “Development of a programme to attract highly specialized human resources from abroad in research, development and innovation activities.”

Total project value: 4.620.000 RON (929.577 Euro)

Project objective

      The main objective of the PredAqua project was to develop and validate mathematical models for predicting trophic interactions within freshwater plankton communities, by integrating ecological network analysis and dynamic simulations with controlled mesocosm experiments.

      The project aimed to advance knowledge on the organization of aquatic communities, identify key groups and interactions, understand direct and indirect ecological responses to perturbations and, in particular, assess the ability of ecological models to predict how biological communities respond to changes in ecosystem structure.

Main activities and results

      During the first stage of the project, representative organisms belonging to the main functional groups investigated – bacteria, phytoplankton and zooplankton – were isolated from an anthropogenic lake in Cluj-Napoca. Culture conditions were optimized, and stable laboratory cultures were established and subsequently included in the Institute’s permanent biological collections, thereby creating a resource that can also support future research.

      These cultures were subsequently used in two complex experimental studies carried out in 2025 and 2026, during the same seasonal period, March–April, using natural aquatic communities maintained in 1,000-L mesocosms. Each annual experiment lasted ten days. The experimental design enabled the testing of 33 perturbation scenarios, each with seven replicates, using dialysis-bag systems. Each of the two experiments generated 942 samples, providing an extensive quantitative dataset for the calibration and validation of the mathematical models. In parallel, water physicochemical parameters and nutrient concentrations were monitored. The structure and abundance of microbial and planktonic communities were characterized using complementary methods, including microscopy, flow cytometry, chlorophyll fluorescence measurements using Phyto-PAM, and molecular analyses based on DNA extraction and sequencing.

      The results demonstrated the importance of integrating experimental data into the calibration of predictive ecological models. The models were able to capture both the direction of major interactions, and their relative strength, revealing cascading effects generated by the experimental perturbations. The analyses also showed that there is no single model that performs optimally under all conditions. Predictive performance depends on how the biological community is represented within the model, including the level of aggregation of functional groups and the number and structure of trophic links. These findings underline the need to calibrate predictive models according to the biological structure and complexity of the ecosystem under investigation.

Dissemination of results and development of research capacity

      The results of the project were disseminated through 21 contributions to national and international scientific conferences and events, with the direct involvement of at least nine team members. These contributions included oral presentations, posters, plenary presentations and invited contributions. During the implementation period, seven scientific articles were published in Web of Science-indexed journals, five of them in Q1 journals.

      Professional-development activities included research visits, scientific missions and international summer schools focused on methodological areas essential to the project, including mesocosm experimentation, flow cytometry, ecological network analysis, and data processing and interpretation. The expertise acquired through these activities was directly applied to the optimization of experimental designs and to the analysis and validation of the predictive models. Through the involvement of researchers at different career stages, including PhD students and postdoctoral researchers, as well as through the development of collaborations with international research institutions, the project contributed to strengthening an interdisciplinary research team and increasing the international visibility of research conducted at the Institute of Biological Research Cluj.

Project impact

      At local and regional level, the PredAqua project strengthened the research capacity of the Institute of Biological Research Cluj in experimental and predictive ecology, through the integrated development and application of methods for culturing aquatic organisms, mesocosm experimentation, plankton-community analysis and ecological network modelling.

      The approach developed within the project provides an experimental and methodological foundation for continuing research on the response of freshwater ecosystems to multiple perturbations. In the longer term, the development of more robust predictive models can contribute to improved monitoring of aquatic ecosystems, earlier identification of ecological imbalances and the development of evidence-based approaches to water-resource management. Through the scale of the experimental programme and the direct integration of mathematical modelling with experimental validation using natural aquatic communities, PredAqua contributes to the development of predictive ecology as a research direction in Romania and provides a foundation for future research projects and international collaborations.

Contact person: Dr. Ferenc Jordán, Dr. Bogdan Drugă

Telephone: (+40)264 598 084

Email: jordan.ferenc@gmail.com, bogdan.druga@icbcluj.ro

Web site:https://icbcluj.ro/en/experimental-food-webs-2/

Publications: https://icbcluj.ro/en/predaqua-publications-2/