Green solutions for sustainable multi-use management of eutrophic waters

The growing anthropogenic change of inland waters brings a variety of challenges. The common denominator of all water-related problems is the destruction of resilience to changes in aquatic ecosystems by reducing biodiversity. Despite great ambitions and strategies to improve the ecological status of water (e.g. the European Water Framework Directive 2000) and the conservation and protection of biodiversity (e.g. EEA 2020, Natura 2000, Biodiversity Strategy 2030), some water-related problems continue to worsen. One of the burning problems causing biodiversity loss is nutrient-contaminated (eutrophic) lakes and reservoirs. According to the data collected by the European Water Framework Directive, there are as many as three quarters of such lakes and reservoirs in Central Europe and as many as 83% in Slovenia. From the point of view of ecosystem services, eutrophic water is unsuitable for ensuring good ecological status of water, recreational and aesthetic values, and above all, such water does not provide a supporting ecosystem function. Due to disturbances in the circulation of water and nutrients and reduced biodiversity, the water body is less resistant to adaptation to climate and other changes in the environment. Very often, such waters have problems with the overgrowth of cyanobacteria, which can pose a health threat due to their potential toxicity. Long-term exposure is of most concern to humans and animals, as it can lead to genotoxic cell damage (some cyanotoxins are associated with tumor formation) and neurodegenerative diseases. The project offers a promising perspective that is essential for the protection, conservation and restoration of eutrophic aquatic ecosystems and their functions. The main goal of the project is to use green approaches to improve the problems of eutrophic waters and to quantify their impact on biodiversity and other ecosystem services. We will focus on the biodiversity of primary producers, which are directly related to nutrients in water and represent food for all aquatic animals. In addition, we will link biodiversity data to the assessment of ecosystem services, which will be used to evaluate the improvement of the state of the water body due to the introduction of a certain green solution. In the first part of the project, we will introduce three different green solutions: (i) nutrient management - floating islands of macrophytes to reduce nutrient concentrations - LIMNOS, (ii) risk management of toxic cyanobacteria by detecting their DNA for early warning system - NIB and (iii) ecological status management based on primary producers by analysis of satellite images in comparison with the results of traditional and molecular monitoring - ARSO, NIB. In the second part of the project, we will link green solution indicators with an assessment of improved ecosystem services (cost-benefit assessment). In addition to scientific publications, the final results will include various tools such as a digital platform, a multi-parametric decision tree, a biodiversity calculator and a model for predicting climate change for eutrophic waters. We will also include satellite image analysis to assess the state of primary producers, which is a key innovation of the project. We will calculate correlations between chlorophyll determined in nature and the chlorophyll signal from satellite images and assess the potential of digital methods for the purposes of monitoring eutrophic lakes and reservoirs. The main purpose of the project is to contribute with scientific data, analyzes and tools to improve water management in the direction of greater resilience of lakes and reservoirs. Synergistic multi-disciplinary cooperation between partners will fill the gap between academia, businesses and government bodies, improve the coherence between theoretical knowledge on the functioning of eutrophic ecosystems and provide concrete guidelines for their conservation and management.