Medvedeva L.A., Nikulina T.V.
V.Ya.Levanidov memorial lectures 2025; (11): 122–141
Samples of periphyton algae were collected in watercourses belonging to the Amur River basin: rivers Gulik, Burinda, Levaya Burinda, Madalan, Chitkan, Urusha, Malomyr, Nagima, Dzhalinda, Motovaya, Bolshoy Yankan; the Sukhonyr, Zhedrinsky and Kazachinsky streams. The species composition of periphyton algae inhabiting the surface of natural substrates was identified. A total of 162 algae species from six divisions were found: Cyanobacteria - 7, Bacillariophytina - 134, Ochrophytina - 3, Charophyta - 8, Chlorophyta - 8, Rhodophyta - 1, Dinoflagellata - 1. All identified algae species are typical river diatoms, often found in the periphyton of rivers in the south of the Far East. The predominant species dominating in the algal communities of the surveyed rivers were Encyonema silesiacum, E. minutum, Gomphonema parvulum, Hannaea arcus, Meridion circulare, Odontidium mesodon, Ulnaria ulna, Achnanthidium minutissimum, Cocconeis euglypta (diatoms). In a number of watercourses the determining role in the algal community was played by rhodophyte (Audouinella chalybea), ochrophyte (Bumilleria, Tribonema, Vaucheria), green (Microspora, Oedogonium, Ulothrix) and filamentous charophyte algae (Spirogyra, Mougeotia). In the Motovaya River, the dominance of dinophyte algae of the genus Gymnodinium was recorded. The poorest algae fouling was noted in the Zhedrinsky and Kazachinsky streams, located within the boundaries of the Albynsky gold mine and most likely exposed to the influence of turbid flows arising during gold mining. An assessment of the ecological state of the watercourses was carried out using the Pantle-Buk method modified by Sladechek based on the presence of algae - indicators of organic pollution. The saprobity index values for individual watercourses varied within the range from 1,02 (Kazachinsky stream) to 1,84 (Burinda River). The surveyed sections of the rivers belong to the oligosaprobic and betamesosaprobic zones, which corresponds to II and III classes of purity, the waters are classified as clean and slightly polluted with a low degree of natural organic pollution. The quantity values of the periphyton algae were mainly due to diatoms. The maximum numbers were noted for the river Dzhalinda (6899,16 mln cells/m2), the minimum for the Zhedrinsky stream (88,92 mln cells/m2) and for the Levaya Burinda River (103,09 mln cells/m2). The highest algae biomass was observed in the Malomyr River (74,685 g/m2), the minimum - in the Zhedrinsky and Kazachinsky streams (0,009 and 0,013 g/m2, respectively).
