eutrophication

Purpose of the work is to characterize the geo-ecological condition of the reservoirs in Lviv in order to develop recommendations for the protection, conservation and enhancement of their functional use. Methods. Field, cartographic, historical, analysis and synthesis. Results. The geo-ecological state of modern reservoirs of Lviv has been investigated. Water pollution of repre-sented reservoirs has been analyzed according to the fund and statistical materials. In the course of the field researches the physical parameters of the water condition have been analyzed, sources of pollution of reservoirs, clogging and overall assessment of coastal water protection strip shave been identified. Most of the reservoirs of Lviv are characterized by littering of the coastal strip, recreational impact, proximity to roads and residential buildings. The color of the water in the majority of the reservoirs is grayish-yellow, the transparency of the water is low, the smell is marsh or earthy-grassy. Ten of the twenty-three reservoirs under study have strong and over Lviv reservoirs is natural. This contributes to the additional intake of pollutants from the catchment area. Ponds where the basin is covered with an artificial surface (mainly concrete) have better water quality. In particular, Levandivskyi has become the only one to have clean water at the beginning of 2019. In recent years, the water reservoirs of the city have been significantly shallow, due to the construction of catchment areas and the discharge of rainwater to the general sewer. Reservoirs near leased restaurants and recreational facilities are in the best condition. The ponds located in park areas (Stryiskyipark, Pohulianka, Shevchenko-ethnopark., Piskovi Ozera) are in a satisfactory geo-ecological state. The most neglected are the reservoirs of former industrial enterprises, which are under control of district administrations. Conclusions. Irrational use of city reservoirs leads to water pollution, siltation and overgrowth of urban reser-voirs, rapid eutrophication, clogging, etc. Taking into consideration the multifunctional importance of reservoirs for the city, recommendations have been developed to improve their geo-ecological state, mainly they are organizational (monitoring the status of reservoirs, introduction of ecological passport of the reservoir, increasing control), technical (separation of rain and municipal sewage, technical care), educational (stands, eco-actions, festivals) measures.

Purpose. Determination of long-term changes in bacterioplankton number in the Dnistrovskiy Estuary in 2003-2018 and data usage for aquatic environment quality assessment. Methods. Bacterioplankton number determination was done using direct microscopy method under microscope with magnification of 1200. Ecological classification of surface waters quality adopted in Ukraine was used for water trophic status assessment. Results. Changes of bacterioplankton quantitative characteristics in summer periods of 2003-2018 have been analyzed. Tendency of increase in bacteria quantity has been revealed in the past eight years, as well as the waters’ trophic status increase from polytrophic in summer periods of 2003-2005, 2007-2009 and 2015-2016 to hypertrophic in 2011-2014 and 2017-2018. Maximal out of all the years bacterial number was identified in July 2012 that exceeded the peak value in the end of past century. Existence of statistical connections between bacterioplankton and water conductivity, transparency, chlorophyll a, pheophytin and total phosphorus were shown. Conclusions. It has been established that microbiological regime forming in the Dnistrovskiy Estuary took place under the influence of natural processes of organic matter production and pollution factors that revealed themselves the most in the middle and southern parts of the estuary. Among the aquatic environment parameters controlled bacterioplankton number, like chlorophyll a, reflected the changes of the Dnistrovskiy Estuary trophic state the most realistic way. At that, index of bacterioplankton is indispensible for indication of water pollution with organic matter of anthropogenic origin.

Purpose. Assessment of the trophic status of water in the Kuchurganske Reservoir in 2006-2018. Methods. Determination of hydrological, hydrochemical and hydrobiological characteristics of the water body's environment has been done using standard methodologies. Four indicators of water eutrophication have been used: chlorophyll a concentration, bacterioplankton number, trophic indices TSI and TRIX. Results. Features of physicochemical characteristics of water in the water-body have been analysed. Higher water temperature has been registered in the middle and lower parts of the water-body compared with its upper reaches. Mineral content increase in water has been found in the direction from lower to upper part; the critical for hydrobionts life decrease of oxygen concentration has been registered in the upper reaches the most often. Analysis of long-term changes in chlorophyll a and bacterioplankton has been carried out. Statistical interconnections have been established between trophic state indicators and physicochemical characteristics of the reservoir. A close positive correlation has been registered between chlorophyll а content and bacterioplankton number, which is caused by the functional dependence of bacteria on the organic matter produced by phytoplankton. It has been shown that with an increase of water volume in the reservoir the value of these indicators of trophic status went down, which was proved by close negative correlation dependence between those values and the depth of water-body. It was demonstrated for the first time that water transparency revealed close significant negative correlation with all the indices and indicators of water trophic status, which evidenced the possibility to use the transparency as a simple indicator of water trophic state as the more transparent is the water the lower is trophicity and the higher is the quality of the aquatic environment. Conclusions. It was established that the Kuchurganske Reservoir’s trophic status assessment on chlorophyll a, bacterioplankton and the TSI trophic index practically coincided and evidenced the increase in trophic status of the water-body from eutrophic to hypertrophic in last 2016-2018. The reservoir’s upper reaches were characterized by higher water trophicity compared with the central and lower parts. The values of TRIX trophic index developed for marine water assessment had practically always been showing higher trophic status compared to other indicators.