I. V. Gribovskaya

Comparative Analysis of Ecophysiological Characteristics of Stephanodiscus hantzschii Grun. in the Periods of Its Bloom in Recreational Water Bodies

In the periods of summer and autumn bloom of the Stephanodiscus hantzschii Crun. in recreational water bodies, studies on the vertical distribution of chlorophyll a, its contents per unit biomass, efficiency in using photosynthetically active radiation (EPhAR), and assimilative activity of microalgae were performed. The results confirmed the existence of two ecophysiological forms of St. hantzschii and provided evidence that both forms are typically autotrophic and can efficiently use low-intensity PhAR for photosynthesis.

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.

Disappearance of phenol in water samples taken from the yenisei river and the krasnoyarsk reservoir

Abstract Using experimental microecosystems the kinetics of phenol disappearance in river and reservoir water were investigated. In river water the disappearance kinetics could be described by a first-order equation, the same kinetics took place in reservoir water before and after the period of “bloom” of blue-green algae. During the “bloom”, the phenol seemed to be mineralized by bacteria which grew at the expense of another compound, and the model of best fit was the model of exponential growth and low concentration of the test substrate. In the river, two sections differed according to the difference between the mean values of the specific disappearance rates. In the reservoir these rates were lower than those in the river. In general the specific disappearance rate values did not correlate with the values of initial bacterioplankton density, the concentrations of inorganic nutrients nor the chemical oxygen demand. Conclusions about the integral influence of ecosystems on the disappearance rates and dependence of self-purification kinetics on the type of aquatic ecosystem were made.

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.

Metal Concentrations in the Ecosystem and Around Recreational and Fish-Breeding Pond Bugach

Data of two field studies were used to analyze the concentrations of Na, K, Ca, Mg, Fe, Mn, Zn, Cu, Al, Cr, Ni, Cd, and Pb in the water, bottom deposits, zoobenthos, fish, and macrophytes of the Pond Bugach and in the soils near the pond. It was established that the majority of metals in the soils and bottom deposits correlate and their concentrations are governed by the universal geochemical factors of the region. The heavy metals were recognized that originate from anthropogenic sources and their concentrations were found to exceed the maximum admissible values for different components of the ecosystem. Five types of heavy metals migration were recognized in the soil–bottom deposits–zoobenthos–fish chain and in macrophytes. Statistically significant difference was found to exist between the concentrations of some heavy metals in the muscles of fish species with different food types (crucian carp and perch) as well as between the correlations of metals. The recorded concentrations were compared with the concentrations of metals measured in the last decade in other limnetic ecosystems in Siberia, Europe, North America, and China.

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.

Metal content in higher aquatic plants in a small siberian water reservoir

The dynamics of metal content in higher aquatic plants (macrophytes) in a small Bugach water reservoir in 1998–2006 was studied. A comparative estimation of the metal content in six macrophyte species (Typha latifolia L., Typha angustifolia L., Polygonium amphibium L., Potamogeton perfoliatus L., Potamogeton pectinatus L., Phragmites australis (Cav) Trin. Ex Steud.) showed that their metal concentrations do not generally exceed those known from the literature. Cluster analysis showed that the macrophyte species under study form two ecological groups with respect to the metal content, i.e., submerged plants (hydrophytes) and emergent aquatic plants (heliophytes).

Physiology-biochemical properties of the cyanobacterium Oscillatoria deflexa

The optimal cultivation conditions for the cyanobacterium Oscillatoria deflexa were studied: temperature (25–27°C), pH (9.0–11.0), and illumination (7 klx). A nutrient medium providing for optimum cyanobacterium growth was selected, as well as media containing an aqueous extract of human urine ash and an inedible material of wheat and vegetables with added nitrates and bicarbonate. The chemical composition (macro and microelements, content of proteins, lipids, carbohydrates, and vitamins, amino acid and fatty acid composition, ash residue) of O. deflexe was studied for the first time. An analysis of the results indicates that O. deflexa is not inferior to the cyanobacterium Spirulina platensis and the green laver Chlorella vulgaris in practical use, for its mineral composition, content of vitamins, essential amino acids and fatty acids, and exceed them in its content of vitamin E and microelements, such as Fe, Mn, Ni. The bacterium’s ability to transport NaCl up to 30 g/l within the medium was studied, and its unique ability for survival and long-term storage was shown. The enhibitory effect of the biomass of O. deflexa on the germination of wheat grains, and growth of daphnids and rotifers was shown.

The Possible Mechanisms of Stimulation of Cyanobacterium Growth by the Passage through the Carassius auratus Intestine: An Experimental Study

In addition to the hypothesis of the direct trophic cascade, only indirect effects of fish on cyanobacteria accounted for excretion of inorganic nutrients into the environment were dealt with in published works [1]. However, the contribution of excretion into cyanobacterial bloom is doubtful in eutrophic water bodies characterized by high concentrations of phosphorus. The phenomenon of viable gut passage of cyanobacteria was first described long ago [2–4]. However, the stimulating effect of cyanobacteria passage through the intestine of planktivorous fish, which may be accompanied by fine biochemical and physiological processes, has not been considered as a possible cause of the appearance and prolonged maintenance of the cyanobacterial bloom.

Chemical composition of water conditioned by crowdedMoina macrocopa (Crustacea: Cladocera)

The chemical composition of water conditioned by colonies ofMoina macrocopa and involved in the regulation of their life cycle was analyzed in comparison with water samples from natural water bodies. Dechlorinated tap water was used as the control medium. The results showed that metabolism of crustaceans leads to an increase in the concentrations of phosphorus and nitrogen in all forms, the appearance of protein and carbohydrate fractions, and changes in the composition of lipid fractions in the water conditioned by their colonies. The contents of all organic components are very low, which makes their identification difficult. Concentrations of substances identified in the conditioned water do not exceed those occurring in nature.