SHANNON DIVERSITY INDICES OF PHYTOPLANKTON IN EXPERIMENTAL FISH-REARING PONDS UNDER THE EFFECT OF DIFFERENT TYPES OF ORGANIC FERTILIZERS

Purpose. To perform a comparative analysis of information diversity indices of phytoplankton development in fish-rearing ponds fertilized with biohumus, Riverm and traditional types of organic fertilizers for the determination of the presence or absence of phytoplankton degradation in these water bodies under the effect of the application of these fertilizers. Methodology. The article describes the results obtained during three years of the studies of phytoplankton in fish-rearing ponds, in which was carp seeds were grown in monoculture and polyculture using intensive and extensive cultivation technologies. The information diversity of algal communities of ponds was determined by calculating the Shannon index based on quantitative characteristics of phytoplankton development. Findings. The performed studies have shown that the application of the studied fertilizers did not lead to the degeneration of algal communities in fish-rearing ponds, which would be expressed as a depleted information diversity of phytoplankton quantitative characteristics; the degree of the information diversity of phytoplankton abundance and biomass varied in time independently; the seasonal dynamics of the informative diversity of phytoplankton biomass was shaped by the amounts applied studied organic fertilizers such as cattle humus, biohumus and Riverm; the seasonal dynamics of the information diversity degree of phytoplankton abundance depends mainly on natural factors; an increase in the abundance of blue-green algae by the end of the season, like algal blooms during the season, is not a consequence of the effect of the applied fertilizer. Originality. For the first time Shannon diversity index was used to characterize the development of phytoplankton in fish-rearing ponds after the application of biohumus and Riverm for their fertilization. Practical value. The obtained results indicate on the promising use of biohumus and Riverm to stimulate the development of the natural food supply for fish, in particular, when growing carp seeds.