Control Of Harmful Cyanobacteria Bloom In Freshwater Bodies

Project coordinator: dr. Domen Leštan, UL BF

Coordinator for NIB: dr. Bojan Sedmak

Code: L1-5456

Duration: 1.8.2013 - 31.7.2016


Occurrence of toxic cyanobacteria bloom is rapidly increasing worldwide because of increasing nutrient input into water bodies and rising temperatures due to the climate change. World Health Organization and national legislatures advise different safety measures including monitoring and control of cyanobacteria bloom. Proposal of new directive of European Parliament and European Counsel also stresses the importance phytoplankton occurrence monitoring. In Slovenia was cyanobacteria bloom detected in at least 35 surface water bodies in a period from 1995 to 2001. The most endangered are Blejsko, Velenjsko, Dvojno triglavsko, Šmartinsko, Slivniško, Perniško, Lendavsko, Gajševsko and Ptujsko lakes, water accumulations Klivnik, Mavčiče in Vrhovo and in some smaller water bodies.    During summer months cyanobacteria rapidly expand their population in warm, slow-moving waters and can completely predominate in lakes and reservoirs. They can actively regulate their position in the water column through buoyancy control, to make maximum use of sunlight and nutrients at optimal times and thus have ecological advantage over other algae. Some of the most potent toxins known as cyanotoxins are produced by cyanobacteria. Eventually, natural causes lead to a gradual collapse of the bloom and release of toxins into the water. Cyanotoxins are hepatotoxic, neurotoxic, dermatotoxic, genotoxic for higher organisms and cause general inhibition of protein synthesis. The highest risk for human health is genotoxicity of microcystins and their effect on internal organs of higher organisms. Although animal illness and deaths have been reported worldwide since the late 1800s, it has only been since around the late 1990s that the drinking water industry and the general public have begun to really understand the negative impact of cyanotoxins on public and environmental health. The first essential measure to prevent occurrence of cyanobacteria and cyanotoxins is to curb water eutrofication. Further conventional water treatments such are precipitation, coagulation, flocculation, chlorination, addition of CuSO With this project we are proposing two innovative approaches towards prevention of toxic cyanobacteria bloom, both are based on ecological characteristics of cyanobacteria. We will investigate efficiency of long distance surface circulation, a preventive measure which de-stratify temperature layers of water body and hydrologicaly disturbs cyanobacteria but does not cause cell death and release of toxins. Second method is based on strategic triggering of lytic cycle of lysogenic cyanobacteria in a space-separated parts of population and release of viruses which cause epidemic of the weakened cyanobacteria population. We are proposing oxidation of cellular membranes with hydroxylic radicals and H Controlling toxic cyanobacteria bloom becomes the critical issue of water body management and will be addressed in the proposed project in technical innovative, ecologically holistic manner. Consortium of public and private research organizations ensures efficient science and technology transfer for future application and technology commercialization in general interest of human health and environment protection. Multidisciplinary team of highly qualified biologists, biochemist, ecologist, environmental engineers and technical physist promises synergy in experimental approach.

Significance for science

Results of the proposed project will contribute to the following novel scientific knowledge:   • Prevention of harmful bloom of cyanobacteria by the method of long distance surface water circulation. • The effect of long distance circulation on water ecology and water macrophytes. • Prevention of harmful bloom of cyanobacteria by H2O2 induced programmed cellular death, caused by oxidative stress and viral infections. • Using an energy autonomous platform to control harmful bloom of cyanobacteria in the real fresh-water bodies. • Using an energy autonomous platform to control harmful bloom of dinoflagelates in the real salt-water bodies. • Monitoring of cyanobacteria populations and prediction of their harmful bloom using automatic measurements and instruments on board of energy autonomous platform. • Using methods of computational fluid dynamics for optimization of components of energy autonomous platform. • Using methods of computational fluid dynamics for modeling the effect of long distance circulation on harmful bloom of cyanobacteria and for optimization of number and locations of energy autonomous platform in the large water bodies.