Journal of Siberian Federal University. Biology / The State of Phytoplankton in Lake Manzherok (the Altai Republic) after Anthropogenic Transformations of the Lake

Full text (.pdf)
Issue
Journal of Siberian Federal University. Biology. 2026 19 (1)
Authors
Vinokurova, Galina V.; Kirillov, Vladimir V.
Contact information
Vinokurova, Galina V.: Institute for Water and Environmental Problems SB RAS (Barnaul, Russian Federation); ; Kirillov, Vladimir V. : Institute for Water and Environmental Problems SB RAS (Barnaul, Russian Federation); ORCID: 0000-0001-9626-7153
Keywords
structural characteristics; bioindication; dredging; anthropogenic impact; eutrophication; lake evolution
Abstract

In recent decades, Lake Manzherok, one of the oldest (12–15 thousand years) lakes in the Altai Mountains, has been subjected to major anthropogenic impact, including dredging, which caused substantial transformations of the lake ecosystem. Considerable changes in the composition and structure of phytoplankton were observed. The authors’ findings (July 2021 and 2023 (3rd and 5th years after lake dredging)) and literature data indicate that the phytoplankton structure and trophic status of the lake changed as the intensity of anthropogenic impact increased. Of the species and intraspecific taxa identified in 2021 (51), 18 % were represented by empty valves of diatoms (from bottom sediments), and in 2023, they constituted 8.2 % of 61 taxa. In 2023, the species diversity of vegetative algae (according to the Shannon index) increased by an average of two times compared to 2021. The coefficient of similarity of the species composition (Sorensen) was only 0.2. The composition of the dominant complex had changed considerably: in 2021, green algae (mainly Volvox polychlamys) were the dominant taxa, while in 2023, euglenophyte and dinophyte algae prevailed, making up an average of 81.64 % of the total biomass. The average algae biomass values decreased from 1960.4 g/m³ in 2021 to 1.38 g/m³ in 2023. In the 3rd year after dredging, the trophic status of the lake was assessed as hypertrophic, while in the 5th year, it varied from oligotrophic to eutrophic in different parts of the lake. The proportion of indicator species reflecting organic pollution (alpha-, beta-, and alpha-beta-saprobionts) in 2023 was 1.7 times higher than in 2021. The proportion of species with a wide range of resistance to organic pollution also increased (by 1.4 times). The results are of interest in terms of the response of the lake ecosystem to dredging, one of the common methods of rehabilitation of water bodies

Pages
74–90
EDN
SZNDYC
Paper at repository of SibFU
https://elib.sfu-kras.ru/handle/2311/158246

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