Lake Baikal Water Research Articles

Colorless sulfur bacteria Thioploca from different sites in Lake Baikal

The colorless sulfur bacteria Thioploca spp. found in Lake Baikal are probably a marker for the influx of subterranean mineralized fluids. Bacteria act as a biological filter; by consuming sulfide in their metabolism, they detoxicate it and maintain the purity of Lake Baikal's water. The bacteria were investigated by various techniques. According to analysis of the 16S rRNA gene fragment, Thioploca sp. from Frolikha Bay, Baikal belongs to the clade of freshwater species found in Lake Biwa and Lake Constance; it is most closely related to Thioploca ingrica.

Determination of 56 Elements in Lake Baikal Water by High-Resolution ICP-MS with the Aid of a Tandem Preconcentration Method

A tandem preconcentration method integrating chelating resin adsorption and La coprecipitation was applied to an analysis of Lake Baikal water by high-resolution ICP-MS. As a result, 56 elements were determined in Lake Baikal water: Ca, Na, Mg, K, Si, Sr, B, Li, Ba, P, Fe, Al, Mo, Zn, Mn, Rb, U, As, V, Cu, Pb, W, Y, Cs, Se, Cr, Ni, Ti, Sb, Zr, Sn, Co, Cd, Rh, Te, Hf, Nb, Ru, Ga, Sc, Th, Bi, and all-rare earth elements (all-REEs), except for Pm. The concentrations of these elements covered a range of nine orders of magnitude, from approximately 17 microg mL(-1) of Ca to less than 50 fg mL(-1) of Tm. The elemental concentrations in Lake Baikal water were compared with reference data.

Vertical Distribution of Lead in Lake Baikal Water Measured by ID-ICP-MS

A vertical distribution profile of dissolved lead (Pb) in Lake Baikal water was measured by an isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS), where the validation of the method was confirmed by the determination of Pb in a river water reference material (JSAC 0302). The concentrations of Pb were generally in a relatively narrow range from 6.39 pg mL−1 to 14.5 pg mL−1, except for that in the surface water sample (194pg mL−1), which might be attributed to the surface input of Pb as airborne suspended particulate, river flow, and other kind of discharge. Furthermore, the concentration of Pb in bottom water sample was also slightly higher than those in the samples collected at other depths, which was attributed to the dissolution of Pb from bottom sediments. On the other hand, the average concentration of Pb in lake water samples collected at various depths was approximately 9.6pg mL−1, which was much lower than those observed by other researchers.

Spectral interferences from polyatomic barium ions in inductively coupled plasma mass spectrometry

For the Element2 (a relatively new high-sensitivity magnetic sector ICP MS), we have studied spectral interferences from barium arising as a result of polyatomic barium ions, which have a considerable effect on the intensity of lines for rare-earth isotopes. We have shown that the parameters characterizing the interferences (the ratios of the signals from oxygen-containing, chlorine-containing, and fluorine-containing BaX+ ions to the Ba+ signal, and the apparent rare-earth concentrations Capp j resulting when overlap from polyatomic Ba occurs) are higher for the Element2 than for a quadrupole instrument (PQ2+). However, it is possible to solve many spectral overlap problems when using the Element2 by using the medium-resolution (MR) or high-resolution (HR) modes. We have estimated the resolutions needed to completely separate the masses of the polyatomic barium ions and the rare-earth isotopes in the spectrum. For cases when it is impossible to use the high-resolution mode due to the ∼100-fold decrease in sensitivity, we recommend preliminary separation of Ba from the rare earths. In this work, we have used extraction chromatography to determine low rare-earth concentration levels in Lake Baikal water.

Hydrophysical processes in Lake Baikal in its transition from subtropical to modern climates

During the past 5 million years significant changes have taken place in the Lake Baikal ecosystem. The climate changed from subtropical, with average annual air temperatures (Tair) of 15–10 °C, to a moderate one with Tair of ~0 °C. The modern hydrophysical regime of the lake has been formed with increase in depth, and gradual cooling of the water body from deepwater temperatures (Tdw) of 15–10 °C to below 4 °C. The processes of cooling of Lake Baikal water in its transition from subtropical climate with deep temperatures greater than those of maximal density (Tmd) are similar to modern processes of deepwater cooling of the Mediterranean type of MEDOC convection. Such intensive mechanisms of vertical exchange (MVE) are similar to autumn homothermy in Lake Baikal. However, they are higher than Tmd. Inverse thermal stratification began to occur in surface layers in cold periods of the year after the deep water had cooled to Tmd. The character of water exchange also changed; instead of a monomictic lake with warm water from surface to bottom, the lake has become dimictic with lower water below 4 °C, i.e. vertical mixing now occurs not once but twice a year. Winter ice cover began about a million years ago.

Search for anomalous effects in geophysical fields in relation to earthquakes in the Baikal rift zone

The paper presents data of electrical conductivity monitoring for the upper crust obtained with the use of a controllable electromagnetic source by the dipole, vertical electromagnetic, and transient electromagnetic sounding methods, as well as variations in the geomagnetic field and the Lake Baikal water level. With the help of spectral, spectral time, and multivariate analyses, main spatial and temporal patterns of variations in geophysical parameters are determined. The present study revealed anomalous effects in the behavior of the canonical coherence (parameter K) and aggregated signal (parameter A) and other anomalous variations in geophysical parameters related to earthquakes in the Baikal rift zone.

Measurements of group velocity of light in the lake Baikal water

The results of direct measurements of group velocity of light in the lake Baikal water at the depth of 1100 m are presented. The lake Baikal water dispersion has been measured at three wavelengths: 370 nm, 470 nm and 525 nm. The results are in a rather good agreement with theoretical predictions.

Preparation and assessment of a candidate reference sample of Lake Baikal deep water

The possibility of the creation of a multi-element reference sample of Lake Baikal deep-water composition is justified. This is a new type of reference sample composed of natural water with a wide range of macro- and microelements. This candidate reference sample has a matrix composition consisting of hydrocarbonate and calcium water, a composition that is typical of many rivers and lakes of the world, as well as rain water. The creation of a candidate reference sample of Lake Baikal water is possible due to the stable water composition at a depth of 500 m, and to the use of water sampling technology which results in the preservation of the initial composition of water and its absolute sterility. Trial batches of Baikal water collected annually and stored in special polyethylenetereftalate bottles for a period of 9 years remained stable and homogenous for most elements. Preliminary data for a range of elements and compounds are presented.

The new BDP-98 600-m drill core from Lake Baikal: a key late Cenozoic sedimentary section in continental Asia

The new 600-m drill core BDP-98 from the Academician Ridge of Lake Baikal recovered a continuous sedimentary record of the past 10 Ma. The entire section is represented by lacustrine sediments, which gradually change from distal deltaic facies at the bottom of the section to fine undisturbed hemipelagic sediments of the upper 300-m interval. The entire 10-Ma lacustrine section contains abundant diatoms, thus allowing extension of Plio-Pleistocene diatom and biogenic silica records into the Miocene. Above the Matuyama/Gauss paleomagnetic reversal boundary, the BDP-98 record contains clearly delineated glacial/interglacial lithologic cycles. Below this boundary the diatom signal is quite different: average diatom contents are higher and variations are of lower amplitude. Although most likely paleoclimatic in origin, these variation presumably reflect past changes in the moisture regime of southeast Siberia under conditions of warm subtropical climate during the Miocene and Early–Middle Pliocene. The continuous BDP-98 drill core, which covers the hiati present in the composite continental sections of the Baikal region, is a key section for reconstructing the Neogene–Quaternary climatic evolution of continental Asia. The BDP-98 section also places several important time constraints on the rifting history of Lake Baikal by providing reliable correlation of lithological and physical properties of the drill core sediments with calculated positions of the acoustic reflection boundaries interpreted from multichannel seismic studies. The lithologic composition indicates that, on the stable block of Academician Ridge where the BDP-96 and BDP-98 drill sites are located, acoustic reflection boundaries are not associated with major erosional events, but instead result from changes in sediment density and composition. Several lithologic indices further suggest that significant changes have occurred in the physics and chemistry of Lake Baikal waters, affecting the carbonate equilibrium and oxygen regime of Baikal.

Determination of bis(2-ethylhexyl) phthalate in water by high-performance liquid chromatography with direct on-column preconcentration

A technique for the direct preconcentration of bis(2-ethylhexyl) phthalate (DEHP) on a reversedphase analytical column was proposed for the analysis of water samples by high-performance liquid chromatography (HPLC). A procedure for determining DEHP in surface-water and atmospheric precipitations in the laboratory and in the field was developed (the limit of detection is 0.1 Μg/L, the limit of determination is 0.3 Μg/L, and the relative standard deviation is 20 or 6% at a DEHP concentration of 0.3 or 10 Μg/L, respectively). The concentration levels of DEHP as a chemical tracer for the transfer and migration of air and water masses were examined in Lake Baikal water and in the snow cover of the Baikal region.

Trace element bioavailability in Lake Baikal

Nuclear physical methods of analysis were used for the determination of some trace elements in the ecosystem of Lake Baikal (water, bottom sediments and the water organisms, phytoplankton, zooplankton, zoobenthos and fish). Our observations suggest that the health status of the Lake Baikal is good and bioavailability of toxic elements is very low.

Hydrochemistry of southern Lake Baikal

Recent chemical indices of water quality of southern Lake Baikal are given: colour, pH, BOD, COD and the principal ions. Chemical homogeneity and stability of the ionic composition of Lake Baikal water compared to observations in the last 30years was confirmed.

Hydrochemistry of southern Lake Baikal

Abstract Recent chemical indices of water quality of southern Lake Baikal are given: colour, pH, BOD, COD and the principal ions. Chemical homogeneity and stability of the ionic composition of Lake Baikal water compared to observations in the last 30 years was confirmed.

Toxaphene contamination in Lake Baikal's water and food web

Water and biological samples were obtained from Lake Baikal in June 1991 and analyzed for toxaphene and other organochlorines. Dissolved toxaphene concentration ranged from 34 pg/L to 143 pg/L and were similar in magnitude to ∑DDT (47 pg/L; sum of 2,4′-DDT, 4,4′-DDT, and 4,4′-DDE) and ∑chlordanes (28 pg/L; sum of cis- and trans-chlordane and cis- and trans-nonachlor). Toxaphene in biota was 1.9 mg/kg-lipid in the pelagic sculpin Comephorus dybowskii, 1.1 mg/kg-lipid in the omul ( Coregonus autumnalis migratorious) and 2.3 mg/kg-lipid in Baikal seal (Phoca siberica) blubber. Toxaphene chromatographic patterns, determined by gas chromatography electron capture negative ion-mass spectrometry, were transformed in the seal relative to either of the fish, which is likely due to the seal's greater ability to metabolize some toxaphene congeners. The major peak in the Baikal seal toxaphene chromatogram was an 8-chlorinated bornane unlike that found by other investigators for narwhal or beluga whale blubber, but similar to ringed seals from the Canadian Arctic.

Acute toxicity of chemicals to Daphnia magna in humic waters

The acute lethality of 13 organic compounds and five heavy metals towards Daphnia magna has been studied in the presence of several natural humic waters. Humic lake water, as compared to humus-free control water, markedly altered the LC 50 values of most of the organic compounds and heavy metals. Most distinctly, the toxicity of fenvalerate, lindane and cadmium to D. magna increased. None of the organic compounds studied, including both weak acids (phenolics) and a base (paraquat), showed decreased toxicity in humic water. The toxicity of copper and mercury, on the other hand, was lower in humic water relative to the control. The toxicity of fenvalerate increased significantly in several natural waters sampled from Finland, and only very small additions (∼0.3 mg dissolved organic carbon (DOC)/l) of humics to control water were effective in this respect. The toxicity of fenvalerate to D. magna in Lake Baikal (Russia) water was, in contrast to all other natural waters studied, similar to that measured in humus-free control water.