Home – Home – Jornals – Contemporary Problems of Ecology 2012 number 4

The assessment of the contribution from the main sources of chemical material into the composition of water in the Novosibirsk water reservoir was carried out. It was confirmed that the chemical composition of water in the Novosibirsk reservoir has been formed essentially due to chemicals inflow from the Ob river.

Analysis of metals, including the group of heavy metals, in the muscular tissue of fish (Leuciscus idus, Rutilus rutilus, Perca fluviatilis, Sander lucioperca) from the Novosibirsk reservoir and the Ob river near the dam of the Novosibirsk water-power station during the year 2009 is presented. The revealed interspecies and interpopulation (biotope) distinctions in metal concentrations are most probably connected with the differences in the food of fish. The level of metal concentrations in the muscular tissue of fish does not exceed the standard level accepted in Russia for fresh fish products.

Dynamics of metal content in higher aquatic plants (macrophytes) in a small water reservoir Bugach during the years 1998-2006 was studied. A comparative estimation of metal content in six macrophyte species (Тypha latifolia L., Тypha angustifolia L., Polygonium amphibium L., Potamogeton perfoliatus L., Potamogeton pectinatus L., Phragmites australis(Cav.) Trin. ex Steud.) showed that metal concentrations in them generally do not exceed those known from literature. Cluster anаlysis showed that the macrophyte species under study form two ecological groups with respect to metal content: submerged plants (hydrophytes) and emergent aquatic plants (heliophytes).

Efficiency of the transfer of gamma-emitting radionuclides in food chains including macrophytes, zoobenthos, fish bentho- and ichthyophages was estimated at the radiation-polluted region of the Enisey river. Essential differences in the efficiency of the transfer of natural and technogenic radionuclides between the components of different trophic levels were revealed. Substantial species-related differences in the accumulation of radionuclides in ichthyophage fish from food were revealed.

Results on the influence of petropollution on the number and age structure of rotifers Brachionus plicatilis under laboratory conditions are presented. The influence of petropollution on the population of rotifers was studied under modeling experimental conditions with the oil concentrations of 5; 10; 20; 40; 80; 160; 320 ml/l of water. Three stages of adaptive reactions of rotifers depending on the concentration of oil were revealed: stimulation, resistance and depression. The age stability of rotifers to petropollution was revealed.

In the course of monthly sampling during the years 2008-2010, two regions of the littoral of the Enisey river were compared, one of them (conventionally pure) was situated upstream of Krasnoyarsk and the other (conventionally polluted) downstream of Krasnoyarsk. The concentrations of heavy metals, oil products, phenols, biogenic elements and essential polyunsaturated fatty acids (PUFA) 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.

Assessment of ecological risk for the change in the content of essential polyunsaturated fatty acids (PUFA) in the plankton of lakes under global warming is carried out. The analyzed hazards are temperature, dissolved phosphorus and nitrogen, phyto- and zooplankton structure. The main risks are related not only with temperature increase, but indirect effects of warming. The critical link in risk assessment of PUFA is phytoplankton structure due to the particularly favorable growth conditions for cyanobacteria in nutrient rich waters in shallow lakes and reservoirs.

Dynаmics of the bacterial plankton community of an eutrophic water reservoir was studied by means of PCR-DGGE in laboratory microecosystems with the addition of amino acid lysine. The data obtained confirm the hypothesis of the narrow specialization of bacterial plankton species to the consumption of separate organic substances..

The study of phytoplankton from rivers and lakes in the southeast part of the West Siberian Plain and the eastern macrosclope of the Polar Ural with the help of scanning electron microscopy has revealed 25 taxa of Bacillariophyta from the class Centrophyceae (Aulacoseira - 7, Cyclostephanos - 1, Cyclotella - 4, Discostella - 2, Melosira - 1, Puncticulata - 1, Stephanodiscus - 7, Thalassiosira - 2), including new species for the flora of the investigated waterbodies. The revision of the species composition of Centrophyceae in waterbodies and watercourses in the southeast part of the West Siberian Plain has allowed more exact identifying the taxonomic spectrum of this class. At present the list includes 55 species, varieties and forms. During the first studies conducted in rivers and lakes of the Lyapin River basin (Polar Ural) 16 species of centric diatoms belonging to the genera Aulacoseira, Cyclostephanos, Cyclotella, Discostella, Puncticulata, Stephanodiscus have been recorded.

Investigation of the number of species and ecology of diatoms of modern bottom sediments in water bodies of the arctic polygon tundra in three sub-regions of Northern Yakutia was carried out. As a result, 161 taxons of diatoms were determined; the determinant role of depth, electroconductivity, pH of the medium, and geographic latitude in their distribution was confirmed, two complexes of species with respect to the leading abiotic factors were distinguished. The diatoms of the first complex prefer shallow water bodies of high latitudes with neutral and slightly alkaline water, and relatively high electroconductivity. The second complex is confined to the water bodies of lower latitudes with small electroconductivity, neutral and slightly acidic water.

Distribution of stomatocysts of chrysophyte algae in the plankton of water bodies of different types in the basin of the middle reach of the Irtysh (at the Omsk Region), as well as in the plankton and in fouling of a deep-water oligotrophic lake Teletskoe (Mountainous Altay) is considered. Classification of the morphotypes of stomatocysts is carried out. The number of morphotypes found in plankton samples from water bodies of the middle Irtysh basin is 30, in Lake Teletskoe - 60. Four similar morphotypes of cysts were revealed for the water bodies under investigation.

The distribution of resting stages of the blue-green algae (akinetes) in the bottom sediments of the littoral of a small Siberian water reservoir is studied. The irregularity (mosaicism) of the distribution of akinetes in the bottom sediments of the littoral is demonstrated, and the possible mechanisms of its formation are anаlyzed.

Concentrations of carotenoids buried in the bottom sediments of Lake Shira (Siberia, Khakasiya) were analyzed over the time interval of the last 2300 years. Carotenoids that are molecular markers of the corresponding groups of phototrophic organisms were detected in the bottom sediments. It was shown that the bottom sediments of Lake Shira are a promising object for climatic reconstructions of late Holocene in Southern Siberia.

Nonsynchronous vertical migrations of copepods Arctodiaptomus salinus were studied in two stratified lakes in the south of Siberia using the method of two-sectional assigned volumes. It was discovered that the presence of pronounced thermocline and the depth maximum of phytoplankton (Lake Shira) promotes intense individual migrations of zooplankton between the zones of epi- and hypolimnion.

Data set obtained in 19 experiments aimed at the studies of the growth of Daphnia of longispina group at the natural seston of the Buigach water reservoir (Krasnoyarsk) was used to analyze the connection of the parameters of somatic and generative growth of animals with the amount and quality of food. Depending on the quality of seston, two models of the development of Daphnia were distinguished. It was demonstrated that in spite of the existing positive correlation between somatic and generative growth, a noticeable fraction of the variations of the specific rate of generative production is determined by external factors of the environment - the relative content of N and -linolenic acid (N : C and ALA : C) in the seston.

Nutrition spectra of dreissenid populations Dreissena polymorpha и Dreissena bugensis inhabiting the Volzhsky reach of the Rybinskoe water reservoir and differing in the perennial dynamics of abundance were studied on the basis of biochemical markers. The features of the nutrition spectra of dreissenids are considered as a possible reason of changes in the abundance of the mollusks.

As a result of integrated studies carried out at the end of August - September 2008-2010, the ichthyofauna and food reserve for fish in Lake Oiskoe (the Ergaky Range) was investigated. The trophic status of the lake was estimated on the basis of the biomass of phyto-, zooplankton and zoobenthos. Relying on calculations of average biomass and production per season for zooplankton and zoobenthos, estimations of potential ichthyomass, fish production and possible fishing amount were estimated.