Fundamental Research

The most important achievements of the Institute for 2014–2024 were the following:

For the first time in world practice, methodological foundations have been developed for determining reference biological components and, accordingly, a comprehensive system for diagnosing, monitoring, and forecasting the ecological status and biodiversity of aquatic ecosystems — a system that can be established as a new scientific-technological direction: "Bioindicative Hydroecology". This work is based on factual material from many years of fundamental research on hydroecosystems of various types, primarily in the Dnipro and Danube basins.

On the basis of a multilevel systems approach, it has been demonstrated for the first time that biological indicators for monitoring the impact of global climate change can be both individual indicator species sensitive to changes in water temperature and the structural-functional characteristics of major biotic communities in ecosystems of various types. Climate changes of different scale and duration lead to an increase in the species richness of invasive aquatic organisms and their role in hydroecosystems. Significant suppression of production processes in primary producers under conditions of anomalously high temperatures has been detected.

Specific features of the ecophysiological adaptation of invasive and native species of fish and invertebrates to the action of abiotic factors of the aquatic environment have been established. Divergent adaptation mechanisms have been identified in different aquatic organisms representing the Ponto-Caspian faunistic complex. It has been shown that prior adaptation of aquatic organisms (molluscs and crustaceans) increases their resistance to the stressful effects of temperature, salinity, and toxicants. In invasive fish species with high adaptive capacity, significant phenotypic variability in physiological-biochemical characteristics and morphometric indicators depending on the conditions of their existence has been recorded.

A new conceptual model of river functioning of various types has been proposed for the first time, and the main flows of matter and energy have been quantitatively assessed via plankton drift, invertebrate drift, and upstream migrations of invertebrates and fish. For small lowland and mountain rivers, the balance has been calculated and diagrams of biotic flows of matter and energy in ecosystem elements have been constructed, taking into account communities of different trophic levels. The diet and feeding dynamics of mass fish species and the role of these processes in the overall energy balance have been studied. The positive role of floodplain water bodies as refugia for biodiversity conservation in river systems for plankton communities and phytophilous fauna has been established.

Methodology has been developed for establishing and determining the values of the main biological and physicochemical quality elements for large lowland reservoirs (using the Dnipro as an example) in different ecoregions of Ukraine. Reference values for the corresponding descriptors have been calculated. Using the Lower Dnipro sub-basin as an example, classification tables for assessing the ecological status/potential of surface water bodies have been developed. Taking into account the WFD approaches to identifying heavily modified surface water bodies and assessing their hydromorphological status, and on the basis of a developed zoning scheme, recommendations for monitoring the Dnipro reservoirs have been prepared, and measures have been proposed for restoring and conserving their natural biodiversity and for the sustainable use of their bioproduction potential.

Biomarkers of climate change in lakes and rivers have been proposed, taking into account ecoregions and altitudinal zonation. In the Eastern Plains ecoregion, biomarkers of climate change proposed include the floristic structure of algal communities and structural changes in benthic cenoses dominated by attached molluscs; in the Carpathian ecoregion — changes in the spatial distribution of benthic cenoses with increasing altitude and changes in the altitudinal location of cyprinid and salmonid fish; in the Hungarian Lowland ecoregion — alien thermophilic invertebrate and fish species; in the Pontic Province ecoregion — thermophilic species of Sino-Indian fauna, oxyphilic and brackish-water species of Ponto-Caspian fauna. It has been established that climate changes and anthropogenic pressure, accompanied by transformation of the hydrophysical and hydrochemical regime, contribute to the formation in some water bodies of conditions that ensure the existence and reproduction of stable populations of alien invasive aquatic organisms (fish, invertebrates, and their parasites) — a biofund for further expansion along the main European invasion corridors. For the first time it has been established that climate changes affect the processes of sequestration of excess CO₂ through the transformation of autotrophic (microalgae and macrophytes) and heterotrophic (macroinvertebrates and fish) components of freshwater ecosystems.

For the first time, a methodology has been developed for assessing ecological risks in aquatic ecosystems under water deficit conditions for the safe use of their resource potential. A typology of hydroecosystems of Ukraine has been carried out, reference values have been established for determining the ecological status of model hydroecosystems, and a mathematical and conceptual framework has been proposed for the methodology of ecological risk assessment — providing the basis for developing compensatory measures when water use for irrigation agriculture is necessary.

It has been established that the lowering of water levels in the Chornobyl NPP cooling pond and surrounding water bodies caused an increase in radionuclide contamination of water masses and an increase in radionuclide accumulation by the biota. This led to a 4–8-fold increase in the absorbed dose rate of internal irradiation of various aquatic organism species due to incorporated radionuclides, primarily ⁹⁰Sr. In addition, due to the replacement of littoral and sublittoral zones of the water bodies that ended up on dewatered territories by sections of the bottom with significantly higher levels of specific activity of ⁹⁰Sr and ¹³⁷Cs, an increase of 15–20% in the external radiation dose of aquatic organisms occurred.

For the first time, a system of comprehensive radioecological monitoring of water bodies has been developed and tested, encompassing the determination of radionuclide distribution in the main components of aquatic ecosystems, assessment of the absorbed dose rate, and analysis of cytogenetic and somatic effects of chronic radiation exposure on aquatic biota. Bioindicative characteristics of higher aquatic plants, molluscs, and fish have been proposed as objects for ecological monitoring in radionuclide-contaminated water bodies.