Issues:
Sections:
Issue 94
GENERAL BIOLOGY
UDK: 583:574.21:574.633
LONG-TERM MONITORING OF PHYTOPLANKTON TO ASSESS THE ECOLOGICAL STATE OF THE VELIKAYA RIVER DELTA
DROZDENKO Tatyana V.,
MEDYANKINA Mariya V.
This paper presents the results of long-term monitoring of phytoplankton communities conducted in the spring periods from 2016 to 2023 in the Velikaya River Delta (the Pskov region). In total, 70 qualitative and quantitative phytoplankton samples were selected and processed. During the research, 293 species and intraspecific taxa of microalgae belonging to 8 systematic groups were registered: Bacillariophytina, Chlorophyta, Ochrophytina, Cyanobacteria, Euglenophyta, Dinoflagellata, Charophyta and Cryptista. The floral complex of the planktonic algoflora of the Velikaya River Delta were based on diatom, green and ochrophytic algae during all the years of observation. The average number of phytoplankton over the entire study period was 1,36±1,25 million cells/l, varying from 597,8 thousand cells/l to 4,13 million cells/l depending on the year. Among the dominant species in the total number, representatives of the Cyanobacteria phylum were constantly noted, and from 2019 to 2023, the unicellular algae Kephyrion doliolum Conrad from the Chrysophyceae class was always present among the dominants. The values of the biomass of spring phytoplankton ranged from 0,20-2,30 mg/l, averaging 0,65±0,75 mg/l over the entire period. The calculated indices of species diversity showed a fairly average complexity of structure of the phytoplankton communities. According to the Milius trophic index, the waters of the Velikaya River Delta in the years under review were defined as oligotrophic or mesotrophic. The conducted saprobiological analysis showed that the delta water quality is characterized as moderately polluted and classified as Class III.
Pages: 20 - 26
Date: 15.11.2024