O. V. Anishchenko

Influence of anthropogenic pollution on content of essential polyunsaturated fatty acids in links of food chain of river ecosystem

In the course of monthly sampling in 2008–2010, two regions of the littoral of the Yenisei river were compared. One of these regions (conventionally pure) was situated upstream of Krasnoyarsk, while the other (conventionally polluted) was downstream of Krasnoyarsk. The concentrations of heavy metals, oil products, phenols, biogenic elements and essential polyunsaturated fatty acids (PUFAs) in various components of the river ecosystem were determined. It was discovered that the anthropogenic pollution causes a decrease in the resources of essential PUFA in the biomass of the upper links of the food chain of the river ecosystem.

Seasonal variations of metal concentrations in periphyton and taxonomic composition of the algal community at a Yenisei River littoral site

The concentrations of metals K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Ni, Pb, Co and Cr, in the water and periphyton (epilithic algal communities) were studied at a site in the middle stream of the Yenisei River (Siberia, Russia) during three years using monthly sampling frequencies. Despite considerable seasonal variations in aquatic concentrations of some metals, there was no correlation between metal contents in the water and in periphyton. Seasonal concentration variations of some metals in periphyton were related to the species (taxonomic) composition of periphytic microalgae and cyanobacteria. Enhanced levels of Ni and Co in periphyton in late autumn, winter, and early spring were likely caused by the predominance of cyanobacteria in the periphytic community, and annual maximum levels of K in periphyton in late spring and early summer were attributed to the domination of Chlorophyta, primarily Ulothrix zonata.

Species-specific stimulation of cyanobacteria by silver carp Hypophthalmichthys molitrix (Val.).

ISSN 0012-4966, Doklady Biological Sciences, 2006, Vol. 408, pp. 223–225.

Distribution and migration of metals in trophic chains of the Yenisei ecosystem near Krasnoyarsk City

Methods of atomic absorption, flame photometry, and emission spectral analysis were used to study the concentrations of metals in water and major ecosystem components of the Yenisei River upstream of Krasnoyarsk City (conventionally background area). The mean bulk concentrations of Al and Cu in water exceeded the MAC for water bodies used for fishery. Cu concentration in freshwater shrimp was found to be reliably higher than that in the link of primary producers (periphyton), and Cd concentration in caddis fly larvae was found to exceed that in water moss. The maximal concentrations of metals among the examined aquatic organisms were recorded in periphyton. Cr concentration in the muscles of Arctic grayling was found to exceed some international standards.

Morphometry and metal concentrations in water and bottom sediments of mountain lakes in Ergaki Natural Park, Western Sayan Mountains

The concentrations of nutrients in water and the total concentrations of metals were determined in water and bottom sediments of four lakes in Ergaki Ridge, which differ in their geographic, morphometric, and hydrophysical characteristics. By the concentration of all examined metals in water and bottom sediments, the lakes can be divided into two groups. The first group includes lakes Oiskoe and Svetloe, which feature large size and depth, while the second group includes small and shallow lakes Raduzhnoe and Karovoe. The concentrations of metals are compared with data obtained for different lakes of other mountain regions and with standards established for their concentrations in water and sediments. The concentrations of Zn and Cu in the sediments of Lake Svetloe were found to exceed the threshold, introduced by international standards, below which no impact on biota is recorded.

Export of biomass and metals from aquatic to terrestrial ecosystems via the emergence of dragonflies (Insecta: Odonata)

Long-term monitoring of the abundance and spatial distribution of 18 widespread species of Odonata has made it possible to assess their contribution to the export of aquatic productivity that entered the Barabinsk forest-steppe ecosystem. The annual emergence of Odonata varies from 0.8 to 4.9 g/m2 of the land area and from 2.3 to 13.3 g/m2 of the water area, which is 4–5 times larger than that in Diptera. The total flux of organic matter from water to terrestrial ecosystems remains relatively stable (sixfold interannual variability) irrespective of large interannual variations in the abundance of separate species (e.g., 42-fold interannual variability in Libellula quadrimaculata). The metal content was determined in nine Odonata species. Export of metals by dragonflies decreases in the series K > Na > Mg > Ca > Fe > Zn > Cu > Mn > Pb > Ni > Cr > Cd. Therefore, odonates appear to be quantitatively and qualitatively important providers of aquatic resources to the forest-steppe landscape of Western Siberia.

Contribution of different groups of autotrophs to the primary production of the mountain Lake Oiskoe

Productivity characteristics of phytoplankton, phytoperiphyton, and five species of macrophytes in the mountain oligotrophic Lake Oiskoe (Ergaky Mountain Range, West Sayan) have been studied. High primary productivity has been noted for phytoperiphyton and macrophyte communities. Photosynthetic parameters of the macrophyte leaves have been compared using a PAM fluorimeter.

Component elements of the carbon cycle in the middle and lower Yenisei River

An integrated study of the middle and lower Yenisei River was performed in the summer of 2012. It involved monitoring the key elements and ecological processes associated with the carbon cycle of the river ecosystem (the study area is more than 1800 km long). Measurements of the production and destruction processes have shown the failure of the “neutral pipe” hypothesis claiming that any river is a simple drain of carbon from terrestrial ecosystems to the ocean. The Yenisei River is not a purely heterotrophic ecosystem. It also has autotrophic areas, where the primary production of planktonic photosynthesis is higher than respiration (above the Angara River and near the Bolshaya and Malaya Heta rivers). According to the data, the respiration rate of the plankton community in the river depends mostly on the water temperature and the content of inorganic phosphorous that can restrict the amount of organic matter consumed by bacterioplankton.