EkoStres
Ecosystems under multiple stressors: an integrated approach to studying population dynamics of freshwater species
Freshwater ecosystems are among the most threatened globally due to multiple anthropogenic pressures, including climate change, pollution, hydromorphological alterations, and habitat loss, all of which profoundly affect freshwater biodiversity.
About the project
Lead institution: University of Zagreb Faculty of Agriculture
Project period: 1 October 2025 – 30 September 2028
The primary objective of this project is to investigate, understand, and elucidate the effects of modifications in lotic and lentic ecosystems, and their consequent impacts on various freshwater organisms, through the integration of multidisciplinary approaches.
Population dynamics
Multiple anthropogenic and environmental pressures on freshwater ecosystems substantially alter fish community composition. Monitoring fish populations provides critical information on their responses to environmental pressures, and supports evidence-based management and conservation.
Morphometry
Morphometric and meristic characters constitute a fundamental basis for species discrimination. However, some species still lack diagnostically reliable morphological traits that allow for clear differentiation among closely related taxa.
Chemical fingerprinting
Chemical analysis of fish otoliths provides valuable insights into their life history, age structure, migratory patterns, and the influence of environmental factors on fish populations. The presence of different polymorphic structural forms of CaCO₃ in varying proportions influences the incorporation of trace elements into otoliths and may serve as an indicator of environmental stress. The calcification of bivalve shells is influenced by environmental factors and is comparable to the mechanisms governing otolith calcification in fish.
Management of aquatic resources
Invasive non-native species pose a significant threat to global biodiversity and ecosystem integrity and represent one of the most important stressors affecting native species in aquatic ecosystems. Within the framework of environmental restoration, the control of invasive non-native species is essential for the successful recovery of native flora and fauna under a holistic, ecosystem-level approach.
Project team
Project leader:
Team members:
Activities and Publications
ACTIVITIES
PUBLICATIONS
December 17, 2025 – First meeting of the project team
3. 11. 2025. – 30. 1. 2026 Internship Melissa Cabrelli and Antoine Fréret (Institut Agro Rennes-Angers, France) – Topic: Morphological and chemical characterization of fish hard structures
February 23–26, 2026 – Dubrovnik–Neretva County – Fieldwork: data collection on invasive species
March 16, 2026 – Second meeting of the project team
31 May 2026 to 5 June 2026 – 61st Croatian and 21st International Symposium on Agriculture
May, June, July, September 2026 – Fieldwork data collection – fish and mussels – six rivers, three ponds, one canal – 20 localities
5 – 9 October 2026 – EIFAAC International Symposium “Managing and Conserving Inland Fisheries and Aquaculture Resources in a Changing World”, Riga, Latvia.
Piria, M., Mrdak, D. (2026). From wide distribution to localised persistence: Status and threats to the European eel in the eastern Adriatic Sea Basin, Croatia. Studia Marina, 39(1), 5–21. https://doi.org/10.5281/zenodo.20377342
Ćaleta, M., Karlović, R., Marčić, Z., Horvatić, S., Zanella, D., Mustafić, P., & Piria, M. (2026). From introduction to impact: Largemouth bass (Micropterus nigricans) in the freshwaters of Croatia. Journal of Central European Agriculture. Accepted 30.7.2026.
Radočaj, T., Špelić, I., Gavrilović, A., & Piria, M. (2026). Ecological impact and establishment of translocated Squalius cephalus in the Lika region. In Ž. Klir Šalavardić & M. Kovačić (Eds.), Book of abstracts: 61st Croatian and 21st International Symposium on Agriculture, 31 May 2026 to 5 June 2026 (p. 173). Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek.
Sood, K., Bogić, D., Špelić, I., Gavrilović, A., Piria, M., & Šalamon, D. (2026). The effect of fishing trap entrance on the morphometry of turtle bycatch. In Ž. Klir Šalavardić & M. Kovačić (Eds.), Book of abstracts: 61st Croatian and 21st International Symposium on Agriculture, 31 May 2026 to 5 June 2026 (p. 175). Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek.
Špelić, I., Novosel, S., Piria, M., & Lajtner, J. (2026). Shell shape variation of thick-shelled river mussel (Unio crassus complex) in Croatia. In Ž. Klir Šalavardić & M. Kovačić (Eds.), Book of abstracts: 61st Croatian and 21st International Symposium on Agriculture, 31 May 2026 to 5 June 2026 (p. 177). Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek.
Dominić, T. (2026). Morfometrijske značajke i kemijska karakterizacija ljuštura školjkaša obične lisanke (kompleks vrste Unio crassus) u Hrvatskoj [Diplomski rad, Sveučilište u Zagrebu Prirodoslovno-matematički fakultet]. Mentori: Izv.prof.dr.sc. Lidija Svečnjak, prof.dr.sc. Jasna Lajtner
Žunac, M. (2026). Usporedba parametara rasta dvije populacije klena (Squalius cephalus) iz različitih vodotoka savskoga slijeva [Diplomski rad, Sveučilište u Zagrebu Agronomski fakultet]. Mentor: dr.sc. Ivan Špelić
Klapan, A. (2026). Morfometrijska varijabilnost ljušture obične lisanke (Unio crassus kompleks) u rijekama dvaju sljevova Hrvatske [Diplomski rad, Sveučilište u Zagrebu Agronomski fakultet]. Mentor: dr.sc. Ivan Špelić
Štimac Varat, M. (2026). Ekologija, ugroze i mogućnosti revitalizacije degradiranih staništa obične lisanke (Unio crassus kompleks) [Završni rad poslijediplomskog specijalističkog studija, Sveučilište u Zagrebu Agronomski fakultet]. Mentor: prof.dr.sc. Marina Piria
Piria, M., Svečnjak, L., Špleić, I., Cabrelli, M., Fréret, A., Lahkar, R., Šalamon, D. (2026). Morphological and chemical characterisation of otoliths in three populations of the invasive mosquitofish Gambusia holbrooki. EIFAAC International Symposium “Managing and Conserving Inland Fisheries and Aquaculture Resources in a Changing World” EIFAAC International Symposium and 34th Session, Riga, Latvia, 5 to 9 October 2026.
Tomljanović, T., Špelić, I., Piria, M., Matulić, D., Radočaj, T. (2026). Spatiotemporal dynamics and ecological status of ichthyocenoses in the Sava River (Croatia). EIFAAC International Symposium “Managing and Conserving Inland Fisheries and Aquaculture Resources in a Changing World” EIFAAC International Symposium and 34th Session, Riga, Latvia, 5 to 9 October 2026.
Gavrilović, A., Jug-Dujaković, J. (2026). Possible solutions for European inland pond aquaculture improvement. EIFAAC International Symposium “Managing and Conserving Inland Fisheries and Aquaculture Resources in a Changing World” EIFAAC International Symposium and 34th Session, Riga, Latvia, 5 to 9 October 2026.
Funding Bodies
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