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Vol. 22 (2019 year), No. 2, DOI: 10.21443/1560-9278-2019-22-2

Zhivoglyadova L. A., Luzhnyak O. L., Shlyakhova N. A.
Hydrobiological communities of Veselovskoye water reservoir (the Manych River) in October 2016: The results of studies

The Veselovskoe reservoir is among the most productive reservoirs of the Manych Cascade. Sharp changes in the hydrological and hydrochemical conditions of aquatic animals' habitat have been typical for the reservoir since its formation. During the intensive succession processes taking place in the reservoir, a restructuring of the plankton and benthos communities was observed accompanied by significant fluctuations in their quantitative indicators. In 2016, there were conducted complex hydrological and biological studies of the reservoir in order to assess the structure of phytoplankton, zooplankton and zoobenthos at the present stage. The western part of the reservoir as the most productive was studied in the autumn by applying standard techniques. According to the data obtained, the phytoplankton abundance averaged 198.1 mln cells/m3, and their biomass constituted 149.1 mg/m3 in the region under discussion, with diatoms and cryptophytes dominating in the phytoplankton community. The abundance of zooplankton averaged 15,298 ind./m3, and its biomass was 42.3 mg/m3. Rotifers dominated in the zooplankton by number, while cladocera and copepods played a key role in the biomass. The zoobenthos number and biomass amounted, respectively, to 3,141 ind./m2 and 7.4 g/m2, the basis of the benthic fauna of the reservoir was formed by oligochaetes and chironomids, whose abundance was predominant, as well as by mollusks that predominated in biomass. Studies of recent decades have revealed a decrease in the phytoplankton and zooplankton biomass in the Veselovsky reservoir. After the successful acclimatization of benthic invertebrates of the Caspian estuary complex and the penetration into the reservoir and development of invasive species, primarily the Dreissena, the abundance and biomass of the bottom community have stabilized and are maintained at a high level due to the malacofauna development.

(in Russian, стр.8, fig. 1, tables. 2, ref 20, Adobe PDF, Adobe PDF 0 Kb)

Vol. 23 (2020 year), No. 2, DOI: 10.21443/1560-9278-2020-23-2

Zhivoglyadova L. A., Safronova L. M., Shlyakhova N. A., Bondarev S. V., Naletova L. Yu., Afanasyev D. F.
Hydrobiological characteristics of the Don River in the region of the Bagayevsky hydroelectric complex construction

The data on the taxonomic composition and quantitative characteristics of planktonic and benthic communities of the Lower Don in the area of construction of the Bagaevsky hydroelectric complex have been presented. In June – July 2018, a comprehensive hydrobiological survey was carried out to assess the taxonomic composition and quantitative characteristics of phytoplankton, zooplankton and zoobenthos. Hydrobiological samples were taken at 21 stations using standard techniques. The phytoplankton communities contained 110 taxa, zooplankton – 58, zoobenthos – 78. The spatial distribution of quantitative indicators of plankton and benthos in the investigated area has been presented. Phytoplankton abundance varied from 2,006.0 to 6,128.0 million cells/m3, biomass – from 1.00 to 7.37 g/m3, the average polygon indicators were 3,636.6 ± 223.5 million cells/m3 and 4.28 ± 0.39 g/m3 respectively. In terms of the number of registered taxa and quantitative indicators, two groups of phytoplankton dominated – cyanobacteria and green algae. The abundance of zooplankton ranged from 2,580 to 238,622 ind./m3, biomass ranged from 36.4 to 476.0 mg/m3, the average abundance was 74,690 ± 15,017 ind./m3 and 172.7 ± 24.8 mg/m3 respectively. Rotifers and cladocerans were the leaders in the number of species. Meroplankton was dominant in numbers (mainly due to mollusk larvae), and copepods were the dominant group in biomass. The number of bottom invertebrates varied from 20 to 17,867 ind./m2, biomass from 0.02 to 2,114.0 g/m2, the average zoobenthos abundance was 3,462 ± 898 ind./m2, biomass 133.9 ± 102.0 g/m2 respectively. The maximum number of taxa was recorded among crustaceans and chironomid larvae. The basis of abundance was formed by oligochaetes and insect larvae, mainly chironomids, mollusks dominated by biomass. The resulting materials can be used as background materials in assessing the impact of construction on the hydrobiological communities of the Lower Don.

(in Russian, стр.7, fig. 4, tables. 3, ref 12, AdobePDF, AdobePDF 0 Kb)