Ecological Systems and Devices Annotation << Back CORRECTION OF THE HYBRID MODEL OF GROWTH OF YOUNG FISHES FROM CALCULATION OF WATER TROPHODYNAMICS A.Yu. Perevaryukha, V.V. Mikhaylov This work continues a series of our studies on the analysis of the nonlinear dynamics of complex environmental processes by computational methods. In the new work we consider construction of a balance model of accumulation of organic substances in a lake, verified according to real data. We explain abrupt changes in the content of nitrogen and phosphorus with the prediction of the further development of eutrophication at the current level of nutrient pressure of nitrogen and phosphorus, caused by anthropogenic factor. Changing the trophic status of the lake has an impact on the well-being of the reproduction of hydrobionts and may cause changes in the composition of the fauna, promote the emergence of introduced, specially planted in the environment the biological species. A modified version of the model of replenishment of bioresources in the calculation of survival for an early ontogenesis of fish in oxygen supply problems is suggested, which can be followed by an unpleasant phenomenon of water «algal bloom». The model uses empirical dependences of the decomposition and precipitation of organic compounds in the lake. Modification of the survival model of the generation of fish, depending on the growth rate of the young, is based on making competitive corrections to the von Bertalanffy equation. The iterative aggregated model was adjusted on the real data of observations of changes in the hydrological parameters of water bodies in China, which were subject to an increase in the runoff of excess nutrient elements. Computational experiments showed the time of the transition of the reservoir to the hypertrophic status at a given level of nitrogen and phosphorus inflow, and the effect of undesirable state on the reproduction of autochthonous and alien species of hydrobionts. Keywords: balance of biogenic elements of the lake; model of trophodynamics; consequences of eutrophication; correction of the model of reproduction and growth of fish; speed of fish growth and provision with oxygen; scenario computing experiments; model verification; alien species. DOI: 10.25791/esip.04.2019.570 Contacts: E-mail: temp_elf@mail.ru Pp. 26-36.