Irina A Morozovskaya

Based on many years of research experience of water techno-ecosystems of thermal and nuclear power plants a brief review of the main patterns of formation of the composition, cenotic structure, elements of the functional organization of benthos and periphyton communities was made. It was shown that the composition of zoobenthos and zooperiphyton in some cooling ponds, other technical water bodies and watercourses was quite rich. In addition, due to the rather intensive invasive process, the list of taxa is constantly expanding. Species of tropical and subtropical origin have been recorded. Of particular importance is the invasion of species that may be the cause of bio-hindrances in the operation of power plant equipment. Techno-ecosystems have been studied to varying degrees. One of the most studied for a long time are the cooling ponds of Khmelnitsky and Chernobyl nuclear power plants. Hydrobiological research and monitoring at the first one has been carried out for more than 20 years. It was found that the influence of biotic invasion (invasion of Dreissenidae) may have a significant impact, comparable to extreme technogenic factors, on both the ecosystem and technical water supply facilities. The stages of contourisation and decontourisation processes in the Khmelnitsky NPP techno-ecosystem were established. At the Chernobyl NPP cooling pond, studies were carried out during all periods of the existence of the reservoir and the power plant, until the process of uncontrolled pond descent and transforming it into a unique wetland. Based on the obtained data, practical recommendations relating to the organization of hydrobiological and environmental monitoring, as well as reducing biological hindrances and improving the reliability of power plant equipment have been developed.

The article deals with the antifouling resistance in the fresh water of the protective coatings based on the ship paint XC-413 containing 5% of hydrophobic cationic biocide 1,3-didodecylimidazolium tetra fluoroborate (DD1M-BF₄). The biocidal additive was found to have high leaching resistance off the coating and improve its hydrophobicity. After 228 days exposure in the Dnipro River the fouling biomass was formed mainly by the Dreissena polymorpha (92.5%). The surface of DD1M-BF₄-modified coatings showed more than twenty time reducing of total biomass comparatively to control substrates. The obtained results showed the considered cationic biocides to be promising antifouling additives for industrial stains, used for protection of the underwater construction and vessels.

The results of the long-term studies of zooperiphyton on experimental substrates were considered. The communities formed over the prolong exposure (from five months to one and a half year) in the bay of the Kaniv reservoir in the Dnieper River downstream Kyiv are analyzed. Over the prolong exposure communities dominated by Dreissena polymorpha are formed, in some cases the bryozoan Plumatella fungosa also was an important participant of these communities. Comparison with background communities of zooperiphyton on anthropogenic substrates was made. The reasons of the periphytic communities' structure modification over the last decades were considered.

New polymeric biocide polyhexamethylene guanidine (PHMG) molybdate has been synthesized. The obtained cationic polymer has limited water solubility of 0.015 g/100 ml, and is insoluble in paint solvents. The results of acute toxicity studies indicate on moderate toxicity of PHMG molybdate which has LD₅₀, 48 h of 0.7 mg/L for Daphnia magna and LD₅₀, 96 h of 17 mg/L for Danio rerio (zebrafish) freshwater model organisms. Commercial ship paint was then modified by the addition of low concentration of polymeric biocide 5% (w/w). The painted steel panels were kept in Dnipro River water for the evaluation of the dynamics of fouling biomass. After 129 days exposure, Bryozoa dominated in biofouling of tested substrates forming 86% (649 g/m²) of total biomass on control panel surfaces. However, considerably lower Bryozoa fouling biomass (15 g/m²) was detected for coatings containing PHMG molybdate. The Dreissenidae mollusks were found to form 88% (2182 g/m²) of the fouling biomass on the control substrates after 228 days of exposure, whereas coatings containing PHMG molybdate showed much lower biomass value of 23.6 g/m². The leaching rate of PHMG molybdate in water was found to be similar to those for conventional booster biocides ranging from 5.7 µg/cm²/d at the initial stage to 2.2 µg/cm²/d at the steady state. This article is protected by copyright. All rights reserved

This article presents results of long-term studies of the communities of Zebra mussel and Quagga mussel in the cooling pond of the Chernobyl Nuclear Power Plant (Ukraine). The peculiarities of the sequential invasion of these two species and the formation of consortium-type communities by them are considered.

Paper deals with data on interrelation of mollusks of the family Unionidae and Dreissena polymorpha (Pallas, 1771) and other epibiotic invertebrates in the cooling pond of the Khmelnitsky nuclear power plant (Ukraine). The quantitative indices of unionids and Dreissena, inhabiting shells of the living Unionidae, size structure of populations, and morphometric indexes of the living Unionidae were analyzed. No significant negative impact of settlements of the zebra mussels on Unionidae was noted.

The specimens of Unionidae with epibiotic druses of Dreissena polymorpha were investigated in the cooling pond of the Khmelnitskiy Nuclear Power Station. The following characteristics were taken into account: the quantitative indices of the development of Unionidae and of Dreissena occurring on the living mollusks and on the shells of dead mollusks, dimensional structure of mollusks populations, and morphometric characteristics of the living Unionidae. An adverse effect of the settlements of Dreissena on Unionidae was not revealed.

Paper deals with analysis of existent views on the concept of consortium and its place in ecological researches. The issue of classification of biocenotic relations in ecosystems is discussed. Examples of consortia and consortium-type communities of different level, and their graphic models are proposed. Ecological conceptions of "ecological engineers" and "keystone species" are discussed. The necessity is argued of development of the biocenotic approach to investigation of hydroecosystems with such significant elements as consortia.