Studies of Hydrochemical and Kinetic Characteristics of Small Water Bodies in the Context of Their Eutrophication

Comparison study data on the hydrochemical parameters, bacterio- and phytoplankton, and reduction–oxidation characteristics of two ponds in Krasnoyarsk are presented. These water bodies are of interest due to the fact that the ecosystems of these natural model objects respond to eutrophication in different ways. It is assumed that the reason for this difference is in the hydrophysical characteristics depending on the morphology of the basins of the water bodies rather than in the hydrochemical characteristics.     

Correlations between fatty acid composition of seston and zooplankton and effects of environmental parameters in a eutrophic Siberian reservoir

During two sampling seasons we analyzed on weekly basis fatty acid (FA) composition of seston fraction <130 μm and zooplankton fraction >130 μm, and compared them using a multivariate canonical correlation analysis (CCA). Besides, we evaluated a possible impact of water temperature and inorganic nutrients on FA composition of the seston and the zooplankton.In spite of significant differences in percentages of several individual FAs, we found very strong canonical correlation (cross-correlation, 1-week lag) between FA composition of the seston and the zooplankton. The most important factor, providing the overall canonical cross-correlation between FA profiles of the seston and the zooplankton fractions was eicosapentaenoic acid (20:5ω3, EPA). FA composition of the zooplankton fraction had comparatively poor correlations with taxonomic composition of the zooplankton. Thus, seasonal variations of FA composition of the zooplankton were determined primarily by seasonal changes in FA composition of the seston, rather than by taxonomic differences of FA profiles between rotifers, cyclopoids and cladocerans. FA composition of the seston was strongly affected by its taxonomic composition, namely by that of phytoplankton. According to CCA, the highest factor loadings pertained to diatoms interacting with their marker acids, including EPA, and cyanobacteria and greens, interacting with their marker acids. Ciliates and small rotifers composed considerable and sometimes major part of the seston biomass, but according to CCA their contributions to seasonal variations of the total FA profile of the seston were insignificant. This finding indirectly support the conclusion of the other authors, that the main source of FAs presented in ciliates and rotifers must be sought in algae and that they do not modify FA composition of food consumed, apart from repackaging it.Water temperature was the principal environmental parameter which drove the overall variations of FA composition. Factor loadings for the inorganic nutrients were comparatively negligible. The main contribution in the seasonal variation of FA composition of the seston was given by negative interaction between water temperature and percentage of EPA in the seston.     

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.