Hydrobiological communities of the middle reaches of the Lena River

• Main Authors: Sidorova, Lena I., Gorokhova, Elena S., Kolodeznikova, Yorinda N.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: 2023
• Subjects: Zoobenthos; Строительство мостового перехода; Гидрохимический анализ; Гидрохимический состав; Зоопланктон; Средняя биомасса; Environmental monitoring; Aquatic biological resources; Zoobenthic organisms; Hydrochemical composition; Hydrochemical analysis; Seasonal variations; Check lists; ASFA_2015::H::Hydrobiology; ASFA_2015::A::Aquatic communities; ASFA_2015::Y::Zooplankton; Yakutsk; lena river; Якутск
• Online Access: http://hdl.handle.net/1834/42778; https://doi.org/10.47921/2619-1024_2023_6_3_66

The investigated site is located within the area of the Yakutsk Urban District and subjected to a high anthropogenic load. The construction of a bridge over the Lena River at its middle reaches is crucial for transport accessibility but will have a negative impact on aquatic bioresources and their habitat. Previously, this section of the river has not been studied, so the results will be indicative of the current state of aquatic biological resources and their habitat. This factor determined the aim of this study: the status assessment of the hydrobionts inhabiting a localized area in the middle reaches of the Lena River. The hydrochemical analysis of water samples has been carried out in the laboratory of the Republican Center for Information, Analysis and Environmental Monitoring (State Budgetary Institution “RIATSEM”); collection and laboratory processing of zooplankton and zoobenthos samples have been conducted according to generally accepted methods. The hydrochemical composition and dissolved gases of the aquatic environment in the localized section of the Middle Lena River in the vicinity of the bridge crossing are favorable for the development of organic life. Zooplankton is represented by 54 species, more than a half of which is comprised by rotifers (52 %). The average biomass of zooplankton in the spring and summer seasons was 1.135 g/m3; in the autumn and winter seasons it was 0.057 g/m3, and the average annual value was 0.238 g/m3. Crustaceans have the highest share in the biomass, and rotifers are the most abundant. Zoobenthic organisms are represented by 9 groups; oligochaetes and chironomid larvae prevail throughout the year. The average biomass of the zoobenthos in the area along the shore was 37.41 g/m2; in the auxiliary streams it was 174.84 g/m2, and in the main course it was 3.52 g/m2. Following the results of this study, the qualitative and quantitative characteristics of the invertebrates have been found to be indicative of a favorable state of their habitat. Участок исследования ...