Journal of Siberian Federal University. Biology / Zooplankton Community Structure of Macrophyte Thickets along a Trophic Gradient in Tributary Estuaries of the Middle Volga Reservoirs

Full text (.pdf)
Issue
Journal of Siberian Federal University. Biology. 2026 19 (1)
Authors
Gavrilko, Dmitry E.; Zhikharev, Vyacheslav S.; Bubnov, Viktor A.; Kudrin, Ivan A.; Tereshina, Maria A.; Erina, Oxana N.; Shurganova, Galina V.
Contact information
Gavrilko, Dmitry E.: National Research Lobachevsky State University of Nizhny Novgorod (Nizhny Novgorod, Russian Federation); ; ORCID: 0000-0002-7759-1625; Zhikharev, Vyacheslav S.: National Research Lobachevsky State University of Nizhny Novgorod (Nizhny Novgorod, Russian Federation); ORCID: 0000-0003-3241-2133; Bubnov, Viktor A.: National Research Lobachevsky State University of Nizhny Novgorod (Nizhny Novgorod, Russian Federation); ORCID: 0009-0006-9842-9009; Kudrin, Ivan A. : National Research Lobachevsky State University of Nizhny Novgorod (Nizhny Novgorod, Russian Federation); ORCID: 0000-0003-2388-629X; Tereshina, Maria A.: Lomonosov Moscow State University (Moscow, Russian Federation); ORCID: 0000-0001-5493-9396; Erina, Oxana N. : Lomonosov Moscow State University (Moscow, Russian Federation); ORCID: 0000-0001-8579-3852; Shurganova, Galina V.: National Research Lobachevsky State University of Nizhny Novgorod (Nizhny Novgorod, Russian Federation); ORCID: 0000-0002-0253-6621
Keywords
rotifers; cladocerans; copepods; species diversity; rivers; trophic index
Abstract

The estuaries of plain-reservoir tributaries are aquatic habitats with extensive shallow zones colonized by aquatic vascular plants. High environmental heterogeneity and the amounts of river-delivered nutrients favour the development of zooplankton communities with increased species richness. However, progressive eutrophication can impoverish species composition. This study investigates changes in the species composition and diversity indices of zooplankton inhabiting different macrophyte thicket types, under varying trophic conditions in the estuaries of the rivers that feed the Middle Volga reservoirs. Zooplankton surveys were conducted from 2018 to 2022 in the tributary estuaries to the Gorky, Cheboksary, and Kuibyshev reservoirs. Trophic status was assessed using the Carlson trophic index (TSI). Results indicated that differences in structural indices of zooplankton communities were driven by the heterogeneity of macrophyte thickets. Greater habitat heterogeneity increased species richness within individual zooplankton taxonomic groups, overall species diversity, and zooplankton equitability in mixed and submerged macrophyte thickets. In the studied estuaries, both total species richness and crustacean species richness decreased with increasing trophic status. Cladocerans responded most strongly to eutrophication. Increased productivity in macrophyte thickets was accompanied by a rise in rotifer abundance. In dominant zooplankton assemblages, cladocerans were supplanted by smaller rotifers, leading to fewer dominant species. Several cladocerans were confined to specific macrophytes, a pattern linked to crustacean feeding, locomotion, and plant’ creation of refuge zones

Pages
91–107
EDN
TCQPEB
Paper at repository of SibFU
https://elib.sfu-kras.ru/handle/2311/158247

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