Assessment of hydrobiocenoses in the small rivers of Argun river basin

• Main Authors: E. Yu. Afonina, A. V. Afonin
• Format: Dataset
• Language: Russian
• Published: Theoretical and Applied Ecology 2017
• Subjects: zooplankton; ichthyofauna; transformation of hydrobiocenosis; gold mining; Verkhnaya Borzya; Srednaya Borzya and Argun rivers; Verkhnyaya; Burbot
• Online Access: https://dx.doi.org/10.25750/1995-4301-2017-3-057-065; http://envjournal.ru/ari/v2017/v3/17307.pdf

Hydrobiological studies were conducted in July 2006, 2013 and 2015 on the Argun river basin tributaries. The area of work is conditionally divided into three sections: natural undisturbed river ecosystems (Malaya Borzya, Chingoratay, Kutomara, Doninskaya Borzya, Verkhnyaya Borzya, Srednyaya Borzya (the upper river part), previously affected by gold mining (Srednyaya Borzya (the middle river part), quarry No. 1, No. 3), currently under the influence of gold washing (Srednyaya Borzya (the lower river part), sediment pond, quarry No. 2.) In total, 73 species and subspecies were recorded in the plankton fauna, 18 species were recorded in the ichthyofauna. 16 species of invertebrates and 8 species of fish were marked in the Verkhnyaya Borzya river basin, 70 and 17 species respectively were in the Srednyaya Borzya river basin. In the zooplankton, widely distributed and eurybiont species are classified as background ones: Euchlanis dilatata Ehrenberg, Bosmina longirostris (Müller), Chydorus sphaericus (Müller), Eucyclops denticulatus (Graeter), Carassius auratus gibelio (Bloch), Leuciscus waleckii (Dybowski), Rhodeus sericeus sericeus (Pallas), Phoxinus lagowskii Dybowski, Cobitis melanoleuca Nichols, Perccottus glenii Dybowski, Parasilurus asotus (Linnaeus) were the common species in the ichthyofauna. The ecosystems of the Verkhnyaya Borzya and Srednyaya Borzya rivers upper sections and their tributaries have preserved their natural state. The greatest transformation was made by the ecosystems in the Srednyaya Borzya river middle part. The zooplankton on the natural sections was characterized by a poor composition (2–3 taxa), the total number varied within the range of 20–90 ind./m3 , biomass varied 0.03–0.56 mg /m-3 with dominance of the crustaceans juvenile stages. In technogenous reservoirs, the its number of species increased to 19–25, and quantitative indices – up to 100–111640 ind./ m3 and 0.45– 561.5 mg/m3 . In the ichthyofauna of the Srednyaya Borzya river was dominated by fish from the boreal plain complex, the ichthyocenosis was characterized as ide-crucian. The fish from the chinese flat complex dominated in the Srednyaya Borzya river, the ichthyocenosis was as ide-crucian-catfish. Technogenic landscapes promoted the spread of the alien species (ratan) and almost complete habitat destruction of the valuable fish species (lenok, grayling and burbot).