E.D. Krasnova

Cryptomonad alga Rhodomonas sp. ( Cryptophyta, Pyrenomonadaceae ) bloom in the redox zone of the basins separating from the White Sea

Bloom of a cryptomonad alga Rhodomonas sp. (Cryptophyta, Pyrenomonadaceae) was observed in the chemocline of saline basins separating from the White Sea, resulting in red coloration of the relevant water layer. According to the sequence of the 18S nuclear rRNA gene, this species was identical to Rhodomonas sp. RCC2020 (GenBank accession no. JN934672) from the Beaufort Sea. The presence of the red layer formed by mass development of Rhodomonas sp. is considered an indicator of a certain stage of separation of a basin from the sea.

The study of coastal meromictic water basins in the Kandalaksha Gulf of the White Sea by spectral and physicochemical methods

Research is initiated to study water samples from stratified water basins in the Kandalaksha Gulf of the White Sea at different stages of their separation from the sea. The objects of research are lakes Elovoe and Nizhnee Ershovskoe located close to the Nikolai Pertsov White Sea Biological Station. Depth profiles of physico-chemical characteristics such as temperature, salinity, pH and dissolved oxygen were measured. Brightly colored green water layers were found in both lakes. Concentrations of photosynthetic organisms were estimated using absorption and fluorescence spectra of water samples from various depths.

Succession Processes in the Anoxygenic Phototrophic Bacterial Community in Lake Kislo-Sladkoe (Kandalaksha Bay, White Sea)

The community of anoxygenic phototrophic bacteria (APB) in the water column of Lake Kislo- Sladkoe (Kandalaksha Bay, White Sea), which has recently become separated from the sea, was investigated in March?April 2012, March?April 2013, and in September 2013. The lake, which was previously considered meromictic, was in fact mixed and was strongly affected by the sea. In winter the lake is sometimes washed off with seawater, and this together with the seasonal cycles of succession processes determines the succession of the community. The consequences of the mixing in autumn 2011 could be observed in the APB community as late as autumn 2013. Green-colored green sulfur bacteria (GSB) usually predominated in the chemocline. In winter 2013 stagnation resulted in turbidity of water under the ice, which was responsible for both predominance of the brown GSB forms and the changes ratio of the species of purple sulfur bacteria (PSB) in anoxic water layers. Production of anoxygenic photosynthesis in the lake was at least 240 mg C m-2 day-1 in September and 0–20 mg C m–2 day–1 in March—April, which corresponded to 40 and 69%, respectively, of oxygenic photosynthesis. Okenone-containing purple sulfur bacteria, strain TcakPS12, were isolated in 2012 from lake water. The ells of this strain form filaments of not separated cells. Strain TcakPS12 exhibited 98% similarity with the type strains of Thiocapsa pendens DSM 236 and Thiocapsa bogorovii BBS, as well as with the strains AmPS10 and TcyrPS10, which were isolated from Lake Kislo-Sladkoe in 2010.

Depth profiles of spectral and hydrological characteristics of water and their relation to abundances of green sulfur bacteria in the stratified lakes of the White Sea

We analyze the results received from two expeditions performed in August-September 2013, August-September 2014 and February 2015 in the Kandalaksha Bay of the White Sea. Depth profiles of hydrological characteristics and optical properties of water were recorded for five marine lakes being on different stages of isolation from the White Sea. Those relic lakes demonstrate a tendency to meromixis and are characterized by apparent stratification of the water bodies from the brackish top layer to the bottom salt water. Maximal concentrations of anoxygenic phototrophs (green sulfur bacteria) were found at depths close to the redox interface in all the studied lakes. To discriminate differently pigmented groups of microorganisms the fluorescence emission spectra of bacteriochlorophylls from the living cells were used. We puzzle out the data on light spectrum propagation through the water body in each lake using optical properties of water (attenuation spectra) in the UV, visible and NIR ranges, as well as direct measurements of the total irradiances at various depths. The changes in optical characteristics of water in the stratified reservoirs due to cromophoric dissolved organic matter (CDOM) and microbial pigments affect the light intensity and its spectral distribution at each water layer thus influencing the living conditions for differently pigmented phototrophic microorganisms and determining the composition of microbial community.

Toward the New Role of Marine and Coastal Protected Areas in the Arctic: The Russian Case

The role of marine and coastal protected areas (MCPAs) is becoming increasingly important in the changing Arctic. These protected areas potentially facilitate the adaptation of natural ecosystems to climate change by mitigating direct anthropogenic threats, balance various kinds of space and resources use, and alert the society to changes taking place in the marine and coastal ecosystems. This chapter explores how a historically established set of coastal and marine protected areas in the Russian Arctic can meet these challenges. Eight strictly protected nature reserves or zapovedniks, one national park, three federal natural reserves or zakazniks, and one nature monument encompass marine compartments or have marine buffer zones. They cover a number of essential biodiversity features: some marine areas within MCPAs may be considered as integral marine ecosystems or include sites of primary importance for ecosystem monitoring because of the existence of long-term observation datasets. The total marine surface area under protection totals nearly 96,000 km2, or about 2% of the areas of the Arctic seas under Russia’s jurisdiction (the Bering Sea excluded). Management of the Arctic MCPAs is a very complex task. It is no surprise that management effectiveness of the federal Arctic MCPAs in Russia is scored relatively low. Potential threats and future challenges to the protection of Arctic marine biodiversity and MCPAs are discussed in this chapter, essentially calling for strengthening the MCPA network. As it is difficult to expect that the number of MPAs in the Russian influence zone can be significantly increased in the next decade, the efforts of conservation organizations should be balanced between advocating for creating new reserves and strengthening the capacity of the existing MCPAs. General remoteness and limited access to most of the Arctic MCPAs call for development of remote sensing and other distant methods for monitoring and surveillance. The challenges for the MCPA network in the Arctic are difficult to meet when using only the inherent zapovednik and national park capacity and governmental support to date. To be effective, establishing a horizontal cooperation and partnership with science, NGOs, businesses, and local communities is the only way for protected natural areas to perform their important mission in a changing Arctic.

Absorption and fluorescence of hydrophobic components of dissolved organic matter in several Karelian lakes with stratified structures

Hydrophobic components of cromophoric dissolved organic matter (CDOM) extracted from water samples and sediments taken in several relic basins located on Karelian shoreline of the White Sea were analyzed using spectroscopic techniques. Those water reservoirs exist at various stages of isolation from the White Sea and represent complex stratified systems of fresh and marine water layers not completely mixing trough the year. Basins separating from the White Sea are the unique natural objects for investigations of properties CDOM, its transformation in the process of turning the marine ecosystem into freshwater environment. CDOM occurring in all types of natural water represents a significant reservoir of organic carbon and plays a key role in the carbon cycle on the Earth. However, aquatic CDOM and nonliving organic matter in sediments from relic separating basins still have not been studied. The target of this work was to study absorption and fluorescence spectra of hydrophobic components of aquatic CDOM from different water depth and sediments in several separated basins of the Kandalaksha Gulf of the White Sea located near the N.A. Pertsov White Sea Biological Station.

Sharp water column stratification with an extremely dense microbial population in a small meromictic lake, Trekhtzvetnoe: Sharp water column stratification

Located on the shore of Kandalaksha Bay (the White Sea, Russia) and previously separated from it, Trekhtzvetnoe Lake (average depth 3.5 m) is one of the shallowest meromictic lakes known. Despite its shallowness, it features completely developed water column stratification with high-density microbial chemocline community (bacterial plate) and high rates of major biogeochemical processes. A sharp halocline stabilizes the stratification. Chlorobium phaeovibrioides dominated the bacterial plate, which reached a density of 2 × 108 cell ml-1 and almost completely intercepts H2 S diffusion from the anoxic monimolimnion. The resulting anoxygenic photosynthesis rate reached 240 μmol C l-1 day-1 , exceeding the oxygenic photosynthesis rate in the mixolimnion. The rates of other processes are also high, reaching 4.5 μmol CH4 l-1 day-1 for methane oxidation and 35 μmol S l-1 day-1 for sulfate reduction. Metagenomic analysis demonstrated that the Chl. phaeovibrioides population in the bacterial plate layer had nearly clonal homogeneity, although some fraction of these cells harbour a plasmid. The Chlorobium population was associated with bacteriophages that share homology with CRISPR spacers in the host. These features make the ecosystem of the Trekhtzvetnoe Lake a valuable model for studying regulation and evolution processes in natural high-density microbial systems.

Spectroscopic Study of Green Sulfur Bacteria in Stratified Water Bodies of the Kandalaksha Gulf of the White Sea

Optical characteristics of water in stratified lakes of the White Sea are of particular interest in connection with the observation of thin colored layers resulting from massive development of anoxygenic phototrophic bacteria around the chemocline. While optical properties of chlorophyll are widely used in remote sensing, spectral characteristics of bacteriochlorophylls (BChl) for natural microbial communities have been little studied. In this work, spectral study of green sulfur bacteria of four water bodies of the Kandalaksha Gulf of the White Sea was carried out. Absorption and fluorescence spectra were measured for water samples taken in March 2017 from different depths and compared with spectra of monocultures isolated from the same water bodies earlier. It has been shown that the BChl fluorescence in the living cells of green sulfur bacteria has two overlapping emission bands: in the region of 740–770 nm (BChl d and e) and at 815 nm (BChl a). The wavelength of the maximum of the first band depends on the ratio of the concentrations of green- and brown-colored forms of bacteria containing different types of BChl. A new method for separating the contributions of two types of bacteria is proposed, based on the deconvolution of the BChl fluorescence spectrum into three bands whose parameters are determined from the spectra of monocultures. The BChl content at various water depths has been estimated and the percentage ratio of different types of phototrophic bacteria has been determined.

Microbial processes in the Kanda Bay, a meromictic water body artifically separated from the White Sea

Sings of meromixis are found by means of microbiological and biogeochemical investigations in the southernn part of the Kanda Bay, an artificial water body separated front the White Sea with a railway dam. The concentration of oxygen in the bottom layer attained 1.9 mmol/L, intensity of the process of microbial sulfate reduction, 3.0 μmol of sulfur/(L day). The concentration of dissolved methane, 3.7 μmol/L. Isotopic composition of carbon in methane (δ13C (CH4) =–79.2‰) indicates to its microbial genesis. At present, Kanda Bay is a sole in Russia man-made marine water body for which there are data on the rate of microbial processes responsible for formation of bottom water layer containing hydrogen sulfide and methane.

Spectroscopic study of the microbial community in chemocline zones of relic meromictic lakes separating from the White Sea

As a result of a recent years study on the Karelia shore of the White Sea more than ten relict lakes in different stages of separation from the sea have been discovered. Five of them are located close to the Nikolai Pertsov White Sea Biological Station of Moscow State University. Such separated lakes are interesting to explore for their firm vertical stratification. Water layers differ not only by temperature, salinity and other physic and chemical characteristics and optical properties, but also by ibhabiting microorganisms and by the quality of dissolved organic matter. To study phototropic organisms in water sampled from different depths we used spectroscopic techniques. Identification of the main bands in the absorption and fluorescence spectra showed that there are two main groups of photosynthetic organisms in the redox zone (chemocline): unicellular algae containing chlorophyll a and green sulfur bacteria with bacteriochlorophylls c, d, e. Spectral data were compared with physical and chemical characteristics of the water layer (temperature, salinity, pH, dissolved oxygen and sunlight illumination at certain depth). It gave an opportunity to compare vertical profiles of oxygen and hydrogen sulphide concentration with the number and distribution of oxygenic and anoxygenic phototrophic microorganisms. Maximum abundance of both algae and green sulfur bacteria were achieved within the redox zone. Typical thickness of the layer with the highest concentration of microorganisms did not exceed 10-20 cm.