Home – Home – Jornals – Contemporary Problems of Ecology 2011 number 1

Spread of the major components of the plankton microbial food chain - bacteria, heterotrophic flagellates and infusoria - in the lower reach of the Ob near Salekhard was studied. In early summer, the level of quantitative development and species diversity of protozoa were not high; heterotrophic bacteria were dominating. Their biomass exceeded that of the phyto- and zooplankton. Anthropogenic activization of bacterioplankton was detected at the river region downstream from Salekhard. The data obtained provide evidence of the importance of heterotrophic microorganisms in trophic dynamics and self-purification of the lower Ob.

Species (clones) of the water-reservoir bacterioplankton living on lysine and glycine were revealed in the experimental microsystems using unsterile cultivation. The structure of the community was anаlyzed using the separation of amplificated fragments of the 16S рRNA gene of the bacteria under the conditions of denаturating gradient gel electrophoresis. Identification of the dominant species (clones) of bacterioplankton was carried out using molecular cloning and determination of the nucleotide sequence of the region of 16S gene of ribosomal RNA. It was discovered that glycine, one of the prevailing amino acids of an eutrophic water reservoir, and lysine, with its lower content in natural water, served as nutrition substrates for different subdominant species (clones) of bacterioplankton. So, it was established that the species of free-living bacterioplankton are narrow-specialized with respect to the consumption of separate amino acids.

For the first time for the Amga, a large river running through Central and South Yakutia, the data on the structure of phytoplankton from the river head to its mouth have been obtained. Patterns of the development of plankton algae groupings and formation of hydrochemical water behavior of the river have been revealed. We also made a complex assessment of the water quality over physical and chemical parameters, saprobic algae and phytoplankton biomass. The background data on the structure of phytoplankton and hydrochemistry of the Amga will serve as the basis for monitoring in the case of possible disturbance of the environmental situation at the river because of the coming operation of the ES-PO oil piрeline.

Generalized data on the composition and structure of phytoperiphyton of the Teletskoye lake on different substrates (stones, higher aquatic plants and their fall) are presented It is noted that, in spite of differences in structure and abundance, periphyton aalgal communities on different substrates have a similar ecological spectrum. This gives one the possibility to use the periphyton algal communities on different substrates to evaluate the quality of water in the lake.

The flora of liverworts (Hepaticae) in the nearest surroundings of thermal sources at Kamchatka is described. It is revealed that the wide propagation of hydrothermal activity over Kamchatka allows conserving some heat-loving taxons and growing a small group of species occurring only in the vicinity of thermal fields over the entire natural habitat. In general, the taxonomix diversity of Hepaticae from thermal habitats is rather low: 45 species have been revealed.

On the basis of the data obtained in collecting the zooplankton samples for 10-day periods in water layer 0-250 m during the years 2001-2004, the saeasonbal dynаmics of abundance and age structure of the natural population of Episсhura baiсalensis Sars, 1900 (Copepoda, Calanoida) from Southern Baikal was investigated. It was established by means of variance analysis that the seasonal changes of abundance and relations between nauplius, copepodites and mature individuals are statistically significant. By means of sample reduction, three phases of the population cycle were identified: growth, peak, and depression of abundance, corresponding to the three biological seasons. The importance of the data obtained for investigating the mechanisms of regulation of the number of population of E. baiсalensis is discussed

It is shown that definite changes of some indicators of plankton structure occur in a zone of input of the products of heron vital activity in eutrophic-hypertrophic lake, which points to an increase in organic and inorganic load. These changes are similar to the changes observed during anthropogenic eutrophication. Also a number of indicators, which are usually not registered under increased anthropogenic influence, are revealed. Results of the studies of polyunsaturated fatty acids in seston and zooplankton indicated that a smaller amount of diatoms and components of terrestrial origin were present in zooplankton food from the site near a colony of herons, in comparison with the food from the background site of the lake. Zooplankton developing in the zone of influence of the herons colony is a higher-quality food for fish; it is rich in DHA, which is a fatty acid essential and necessary for their growth and development.

Zoobenthos of the main biotopes in the drainаge zone of the Novosibirsk water reservoir was studied for the first time. Composition and quantitative characteristics on dry sections was determined depending on soil composition, drainаge duration, distance from the permanently flooded zone, and the position above the minimal level of the reservoir. It was shown that the major destruction of the zoobenthos occurs during reservoir filling periods.

The structure of the communities of non-commercial fish parasites in the Kacha river (a tributary of the Enisey) was determined for the first time. The studied communities are formed mainly by generalist species (68 %) with an insignificant fraction (16 %) of specialist species. According to the frequency of occurrence, only one species (Trichodinella epizootica Raabe, 1950) with the occurrence frequency > 70 % is related to the basic ones and three to secondary ones (Paratrichodinа incisа, Lom, 1959, Diрlostomum phoxini Faust, 1918, Rhabdochonа denudatа (Dujardin, 1945)). All the other species (46) are additionаl. Characteristic features of the parasitic faunа of fich in the Kacha river are very low indices of the species similarity according to Jacquard, which is an evidence of the originаlity of ecological niches of the studied hosts.

Metal content (Мn, Zn, Pb, Cd, Со and Hg) in the muscular tissue and liver of the fish of different trophic levels from the Kichera river (Severobaikal'sky Region, Republic of Buryatia) was investigated.

Expansion, mode of living, reproduction, nutrition, infectiousness with helminthes, seasonаl variations of hematological indices, content of ascorbic acid in organs and glycogen in liver were studied.

Water biotesting in the Amur Bay of the Japanese sea was performed using protophyte algae Phaeodactylum tricornutum Bohl. during the years 2007 and 2008. It was revealed that the number of cells, content of chlorophyll a and carotenoids of the microalga grown in the water under test deviated from those in the reference samples during all the seasons of investigation. Our results confirm previously obtained data on the unfavorable ecological situation in the bay and the negative action of its water on hydrocoles.

Effect of different oil concentrations in aqueous medium on chlorella alga and daphnia was studied in laboratory experiments. It was shown that with an increase in oil content in water, the intensity of delayed fluorescence of the test culture of chlorella and the survival probability of daphnia decrease. However, for chlorella, a decrease in fluorescence as an index of its photosynthetic activity is observed only for very high oil concentrations (1000-2000 MPC), while for daphnia the survival probability decreases starting from 4 MPC. A similar dependence is also observed when sunflower-seed oil imitating oil pollution is introduced into the medium. It is assumed that the negative effect of oil on microalgae and daphnia is due to physical factors rather than chemical ones.

River water containing a set of pollutants causes substantial changes in the amylolytic activity of human saliva and affects the kinetics of fat hydrolysis under the action of pancreatic lipase. In fish living in polluted water, specific features of the distribution of ascorbic acid over the tissues of organs were detected; a decrease in the amount of cavity fat and lower content of polyunsaturated fatty acids in it were also observed. The monoamine exchange in the liver of fish is impeded under the effect of the soluble fraction of oil. The applicability of the used biochemical methods for evaluating the quality of natural water was demonstrated.

Some negative processes that occur at the territory between the ob and the Tom were revealed. The indices of the degradation of environment are lowering level of ground stagnant water, changes of the water schedule of soil and withering of shallow-lying peat swamp, changes of the plant cover and productivity of tree stand. Indication of environmental distortions on the basis of the state of forest and bog ecosystems revealed a chronological and territorial connection with the start of operation of the Tomsk water intake and the formation of the cone of depression in the horizon of underground water. The most strongly transformed landscapes are those semi-and hydromorphic ones along the first succession of water intake. The landscapes along the second and the third successions of water intake are less transformed.

Results of the analysis of chemical composition and evaluation of the quality of bog water at the territory of the river basin within the southern taiga subzone of West Siberia are presented. It was stressed that the features of the composition of bog water, from the viewpoint of the accepted maximum permissible concentrations, allow one to characterize the water as undoubtedly polluted. However, the observed high concentrations of some components are caused first of all by natural processes that take place in peat bed but not by industry-related pollution.