Phytoplankton as an indicator of the current ecological status of the Ob River

[摘要] The species composition, taxonomic structure, and the dominant complex of algae, and the distribution of phytoplankton abundance in the studied watercourse were identified based on data obtainedfor phytoplankton from the Ob River (from Tomsk to Salekhard) in summer 2019. Green algae (division Chlorophyta) make up the basis of the phytoplankton abundance in the river. The dominantcomplex is represented mainly by centric diatoms (genera Aulaсoseira, Cyclotella, Stephanodiscus) andnon-heterocyst forms of cyanoprokaryotes (genus Aphanocapsa). The numbers and biomass of phytoplankton gradually decrease downstream of the Ob River; below the confluence of the Irtysh River, theedge effect occurs: increase in the diversity and density of organisms at the boundaries of ecosystems.Compared to the previous studies, the proportion of green and euglena algae, and cyanoprokaryotesin the taxonomic spectrum of phytoplankton increased, the composition of the dominant complexenriched, including due to non-heterocyst forms of cyanoprokaryotes, and the trophic status of theriver increased to the category of eutrophic waters.

[学科分类] 外科医学

[关键词] Dominant complex;phytoplankton;species composition;taxonomic structure;trophic status