MICROPHYTOBENTOS OF THE RIVER MERTVOVID

Abstract

Microphytobenthos of the River Mertvovid was studied for the first time. The river Mertvovid belongs to medium rivers of Ukraine and us a left tributary of the River Pivdennui Bug. The natural complex of Aktovskyi canyon, which was formed on the banks of the Mervovid, is a part of the regional landscape park Granitno-Stepove Pobuzhzhia, created in 1994 by Mykolaiv Regional Council.The aim of the research was to determine the modern state of microphytobenthos of the River Mertvovid. Microphytobenthos was studied on sandy and silty soils for 2009-2010 years at three stations near Voznesensk town. 52 species of algae, which belong to 3 phyla, 4 classes, 12 orders and 33 families, were identified as a result of the research, carried out in microphytobenthos of the river Mertvovid. Among them 51 new species for the said water reservoir were registered. Among the species composition rare for Ukrainian territory species of diatoms: Navicula jentzschii Grunow, Navicula alineae Lange.- Bert., Stenopterobia curvula (W. Sm.) Krammer were identified. The population of algae constituted 68.17–124.29 mln. cells/m², biomass constitutes 0.11–2.62 g/m².Among the species composition of the algae of the River Mertvovid representatives of phylum Bacillariophyta (43 species) dominated over species from phyla Chlorophyta (5 species) and Cyanophyta (4 species). With respect to the water salinity species composition of microalgae of the River Mertvovid is fresh water-saltish water (oligohalobs – 61.54%, mesohalobs – 19.23%, polyhalobs – 5.77%).Saprobic index of the River Mertvovid waters constituted 2.01, the majority of the microalgae of the research area are inhabitants of moderately polluted waters α-mesosaprobs – 21.15%, β-mesosaprobs – 44.23%. The largest population of algae was registered in April 2010, and the lowest in October 2009.