SPLEEN LEUKOCITE COMPOSITION OF SIBERIAN ROUCH AND GOLDFICH, INFECTED WITH PLEUROCERCOIDES THE GENUS LIGULA (CESTODA: PSEUDOPHYLLIDEA)

In our study, we obtained new data on the leukocyte composition of the spleen of Siberian roach and goldfish infected with Ligula interrupta and Ligula intestinalis, respectively, in a comparative aspect. The sample of fish consisted of non-aquatic catches, the same size-age composition (age + 3 ... + 5, body length 145–237 and 150–180 mm, respectively, weight – 100–184 and 120–174 g) from water bodies of the Baikal lake basin (Dolgoye lake, Cheremukhovoye, Gusinoye). It is noted that in the spleen of goldfish the number of lymphocytes did not change in general, but there was a significant change in the ratio of mature and immature forms: the number of prolymphocytes decreased by 1.5 times, and the content of mature lymphocytes increased by 3.8 times. Unlike goldfish, the infected roach showed the formation of vacuolated cells up to 5.3%, and intense leukopoiesis processes are observed, which is confirmed by a higher content of blasts (by 3 times). Among the granulocytic reactions in fish, similar reactions were observed along the line of neutrophils: a significant increase in poorly differentiated forms in goldfish, as well as mature microphages in roach. It has been shown that, in these parasitic systems, ligulid larvae can be modulators of the adaptive immune response.

Ice jam flood risks on the rivers of the Baikal Basin

The article presents the results of analysis and assessment of risks related to ice jams on the rivers of the Baikal Lake Basin. It also proposes the recommendations for mitigation and rational development of coastal areas. Data on catastrophic ice jam floods for more than 100 years is presented, the factors of their formation and mechanism of their movement are considered. On the basis of official statistics from expedition surveys, potentially dangerous jamming areas have been identified, and the repeatability and extent of floods have been calculated. With the help of ArcGIS package the scale of possible flooding was determined, which allowed to reveal the list of economic objects within the damage area. Specific indicators have been used to calculate the expected damage to territories, facilities and population from the flood hazard. Analysis and assessment of economic risk from the floods on the Selenga River are given. Measures to minimize risks of negative impact of floods are proposed.

NIGHT MIGRATION COMPLEX OF ENDEMIC AMFIPOD AS AN INDICATOR OF ENVIRONMENTAL STATE BAIKAL LAKE

With the ongoing anthropogenic eutrophication of the Lake Baikal there is an increase in the abundance not only of aquatic vegetation, but also organismsconsumers. As consumers of vegetable detritus are crustaceans – amphipods, which, by eating detritus, partially reduce the pollution of the lake with rotting organic matter. A significant increase in their number is evidenced by the increase in the abundance of amphipods in the nocturnal migratory complex in the coastal pelagic zone.

SOILS OF EASTERN COAST OF BAIKAL LAKE AND THEIR ECOLOGIC-MICROBIOLOGIC CHARACTERISTIC

In this paper, we discuss new experimental data on the soils from eastern coast of the Baikal natural territory. We provide description of the soils, also the acid-alkaline conditions (from pH 5.1 to 7.9) and humus content (from 0.1 to 13.8%) were determined. The degree of biological activity determined by express method per-mitted categorizing soils as moderately and weakly active. We revealed a noticeable (on Chaddock’s scale) relationship of this activity with acid-alkaline conditions (R2 = 0.52). The quantitative-qualitative characteris-tics of soil microbiocoenoses were studied in details, revealing a high diversity of the main systematic groups of organisms. Qualitatively, the fugal component was very diverse. The specific feature of soils was the absence of the most common microscopic fungus Aspergillus niger, which is characteristic for the other Siberian soils. The investigated soils were found to be epidemiologically safe.

Accumulation of heavy metals in aquatic vegetation of the Barguzin River

This study is devoted to the analysis of the distribution of heavy metals in the aquatic system of the Barguzin River. This is one of the largest rivers of the Baikal lake system. The element composition of the aerial scion of Potamogeton pectinatus L. (syn. Stukenia pectinata (L.) Borner), Potamogeton perfoliatus L., Hippuris vulgaris L. and Nymphoides peltata (S.G. Gmelin) O. Kuntze of the Barguzin River is studied in this research. One of the main results of the study is the establishment of the following sequence of the accumulation of metals in aquatic plants: Mn > Fe > Сu (Zn) > Сr > Ni > Сo > Pb > Cd > Hg. Hippuris vulgaris L. contains the highest concentration of the studied metals. Thus, this research provides one of the important steps for the development of regional environmental standards and environmental risk assessments.

Sculpin Cottus cf. poecilopus Heckel, 1837 in Baikal Lake Basin: First Findings

For the first time for the Baikal Lake basin, evidence of the existence of populations of sculpin Cottus cf. poecilopus Heckel (alpine bullhead) characteristic of the adjacent Lena River basin in large northern Baikal tributaries, the Verkhnaya (Upper) Angara and the Kichera is provided. In June 2009 during the study of the lower reaches of the Kholodnaya River (Kichera-Baikal system), 8 individuals of sculpin aged from 3 to 5 years and in August 2009 5 more specimens aged from 4 to 6 were caught. All fish were fertile with the gonads in maturity stage III. In August 2010 33 individuals aged from 4 to 6 were collected in the main channel of the Upper Angara near Novy Uoyan settl.. At about the same time C.poecilopus was registered in stomachs of Arctic charr from Lake Amut (Churo-Upper Angara-Baikal system) near the divide with the Pravaya (Right) Mama (Mama-Vitim-Lena system). In August 2010 17 specimens aged from 1 to 4 were caught in the Upper Angara near the mouth of its large left tributary the Yanchui River. Sculpins from the rivers Kholodnaya, Upper Angara and Yanchui have higher growth rate as compared to the ones from mountain lakes of the upper Lena basin. About 90 % of males and females matured at the age of 3 years. Absolute fecundity of two females from the Upper Angara River was 149 and 556 (with a mean of 352,5) eggs and of two females from the Kholodnaya River, 223 and 305 (with a mean of 264) eggs. This exceeds the fecundity of sculpins from mountain lakes in the Lena part of Baikal rift zone, which averages less than 150 eggs. Sculpins spawn in the Kholodnaya River in the 1st half of June. The diet of C. cf. poecilopus all over the Baikal basin as well as in adjacent sites in the Lena basin was basically composed of larvae of amphibious insects (trichopterans, ephemeropterans, chironomids and plecopterans). The discovery of the third species from the Lena basin in the Baikal basin following the findings of Arctic charr Salvelinus alpinus and grayling Thymallus baicalolenensis evidences the absence of differences in the structure of ichthyofaunas of the upper parts of both neighboring basins. Sculpins permeate along the streams to mountain lakes more easily than other species and colonize the most elevated ones in lake cascades within the northern part of Baikal rift zone. Their dispersal across the divide could proceed in two ways: via headwater captures or via flattened passes between converging upper reaches of adjacent streams.