Analysis of the hydrochemical state in fisheries water bodies

Purpose. To assess the quality of the temperature and hydrochemical regime of ponds during the cultivation of common carp and Chinese carp during the growing season. Methodology. Determination of physical properties and gas composition of water (temperature and content of oxygen dissolved in water) was carried out directly at the place of sampling. Measurement of the chemical indicators of water — the content of ammonium nitrogen, nitrites, nitrates, phosphates and total iron - was determined by the photometric method and the concentration of chlorides — by the argentometric titration method. The hydrogen indicator (pH) was determined electrometrically, and the content of sulphates and mineralization - by the gravimetric method. All the above-mentioned methods are the most significant parameters in the comprehensive assessment for the state of aquatic ecosystems. Findings. In laboratory conditions, the main components of the chemical composition in pond for fisheries, which characterize its physical properties (hydrogen pH index, hardness), salt composition (chlorides, sulphates, calcium, magnesium, sodium, and hydrocarbonates), biogenic elements (ammonium nitrogen, nitrites, and nitrates), phosphates, iron. The obtained results of the laboratory analysis of the chemical composition of water samples, as well as their comparison with the maximum permissible concentrations of substances (MPC) in water bodies for fisheries provide grounds for certain conclusions about the ecological state in accordance with purpose to the cultivation of common carp and Chinese carp. Originality. Continuation study of the seasonal fluctuations dynamics of the temperature and chemical regime in the fish ponds of the SE “Research farm “Nyvka” (Kyiv) during the vegetation season of common carp and polyculture (common carp and Chinese carp) in order to outline the potential opportunities for commercial fish cultivation under the influence of abiotic factors. Practical Value. The obtained results are necessary to establish the possibilities for using ponds with the purpose of growing some types of marketable fish, namely: common carp and Chinese carp.