Shershnevskoe Reservoir is the main source of water supply of the Chelyabinsk city (South Ural, Russia). It is an artificial reservoir, filled in 1963-1969. The water protection zone of the Shershnevskoe Reservoir is subject to significant anthropogenic impact. Variations in phytoplankton community composition in the artificial waters are still poorly understood. The purpose of this work is to study the changes in the composition of phytoplankton that have occurred since the creation of the reservoir. Identified taxa (381) of the phytoplanktonic community in 1965-1985 are as follows: 150 Chlorophyta, 123 Bacillariophyta, 69 Cyanophyta, 25 Euglenophyta, 6 Chrysophyta, 6 Xantophyta, 1 Dinophyta and 1 Cryptophyta. Identified taxa (134) of the phytoplanktonic community in 2004-2017 are as follows: 67 Chlorophyta, 26 Bacillariophyta, 25 Cyanophyta, 9 Euglenophyta, 4 Chrysophyta, 2 Xantophyta and 1 Dinophyta. The dominants were blue-green algae. The presence of Cyanobacteria as the dominant complex indicates a high degree of eutrophication of the reservoir. The following species were dominant until 2014-2015 Aphanizomenon flosaquae Ralfs ex Bornet & Flahault, Snowella lacustris (Chodat) Komárek & Hindák and Microcystis aeruginosa (Kützing) Kützing, but after 2014-2015 it is Planktothrix agardhii (Gomont) Anagnostidis & Komárek. Over the fifty years of the existence of the Shershnevskoe Reservoir, its ecological state has passed from a long-term sustainable mesotrophic to a eutrophic one.

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Krupnova TG, Mashkova IV, Kostryukova AM, Egorov NO, Gavrilkina SV. 2018. Bioconcentration of heavy metals in aquatic macrophytes of South Urals region lakes. Biodiversitas 19: 296-302. This paper studies bioconcentration of heavy metals in macrophytes. High concentration of heavy metal compounds in the lakes of South Ural is natural. Moreover, some of the South Ural lakes are polluted by heavy metals that get into the water together with partly treated sewage of ferrous and non-ferrous industries as well as mining. The paper analyzes similarities and differences of macrophyte communities in six lakes: Bolshoye Miassovo, Bolshoy Ishkul, Bolshoy Tatkul, Argayash, Savelkul, Baraus. In our research, we determined species diversity for each lake. Potamogeton lucens L. and Lemna minor L. were found in all the studied lakes, and the concentrations of heavy metals were studied in their leaves. Such metals as Fe, Mn, Cu, Zn were found in macrophytes. We obtained a metal ratio Mn <Fe<Cu<Zn in plant leaves. High accumulation of Fe, Cu, Zn was observed in Lemna while Mn accumulates equally. Metals bioconcentration factors (BCFs) were calculated

Kostryukova AM, Krupnova TG, Mashkova IV, Gavrilkina SV, Nikita O. Egorov NO. 2018. Phytoplankton diversity in threelakes of South Ural, Russia. Biodiversitas 19: 1459-1467. Preservation of water ecosystems in their natural state is of great significance.Phytoplankton is one of the biotic indicators of the lake trophic status and ecological state. This study deals with phytoplankton diversityof three lakes of South Ural, Russia. The studied lakes represented different trophic states: Lake Savelkul was oligo-mesotrophic, LakeIlmenskoe was mesotrophic and Lake Argayash was eutrophic. The species composition of common phytoplankton was recorded inJune-July months during 2015 and 2016. The Cyanophyta (blue-green algae) species were dominant in Lake Ilmenskoe(42-64%) andLake Argayash(55-70%). The Bacillariophyta (diatom algae) species were dominant in the Lake Savelkul(40-66 %). The most commondiversity indices namely the Shannon Index, Simpson Index and Margalef Index were determined and the data was also analysed usinggraphs. The graphs were constructed by the similarity calculating method on the basis of the Sorensen-Czekanowski coefficient.Diversity indices confirm the higher species richness of the microalgal community of Lake Ilmenskoe, classified as mesotrophic. It wasshown that the lakes have sufficiently high biodiversity and high ecosystem resilience. Further, statistical analysis (CCA) revealed thatorthophosphate-phosphorus, nitrite-nitrogen and pH were the most significant environmental factors influencing phytoplanktoncommunity of the lakes studied.

Kostryukova AM, Mashkova V, Krupnova TG, Egorov NO. 2018. Phytoplankton biodiversity and its relationship with aquatic environmental factors in Lake Uvildy, South Urals, Russia. Biodiversitas 19: 1422-1428. Lake Uvildy is one of the largest and the most unique of the South Ural region lakes. This mountain deep lake, which has the status of a natural monument. The purpose of this paper was to study the phytoplankton community structure and the aquatic environmental factors in Lake Uvildy. The phytoplankton samples were collected from 5 sites of Lake Uvildy, then filtered through the plankton net and were preserved in 5% formalin. Species were identified using the handbooks by Sladecek, Yarushina, and Al-Kandari. Water samples were taken for water quality analysis. The several physicochemical parameters were measured in situ by a Portable Meters (Multitest IPL-513 and Multitest KSL-111, Semico Ltd, Russia, Novosibirsk). The others parameters were measured in the laboratory of the Department of Chemistry of the South Ural State University according to the standard methods. The sampling was made during the vegetation period in June-July 2014. The water quality was evaluated using the Shannon biodiversity index. A total of 38 species (11 phyla, 31 genera), including 9 species of Chlorophyta, 13 species of Bacillariophyta, 9 species of Cyanophyta, 4 species of Euglenophyta, 2 species of Chrysophyta, 1 species of Dinophyta, were identified. The phytoplankton species in the lake were mainly represented by Cyanophyta and Bacillariophyta. There were 5 dominant species: Fragilaria crotonensis, Asterionella formosa, Dolichospermum lemmermannii, Microcystis aeruginosa, and Coenococcus planktonicus. The Shannon index value comprised 1.27-2.21. According to the saprobity index values (1.63-2.35), the water in the late is evaluated as satisfactorily clean. Physico-chemical parameters were factors driving the change in phytoplankton community composition in Lake Uvildy.