Russian Coast Research Articles

Observations of Tsunami Waves on the Pacific Coast of Russia Originating from the Hunga Tonga-Hunga Ha'apai Volcanic Eruption on January 15, 2022

The Hunga Tonga-Hunga Ha´apai volcanic eruption on January 15, 2022 generated a tsunami that affected the entire Pacific Ocean. Tsunami from the event have been generated both by incoming waves from the source area, with a long-wave speed in the ocean of ~ 200–220 m/s, and by an atmospheric wave propagating at a sound speed ~315 m/s. Such a dual source mechanism created a serious problem and was a real challenge for the Pacific tsunami warning services. The work of the Russian Tsunami Warning Service (Yuzhno-Sakhalinsk) during this event is considered in detail. The tsunami was clearly recorded on the coasts of the Northwest Pacific and in the adjacent marginal seas, including the Sea of Japan, the Sea of Okhotsk and the Bering Sea. We examined high-resolution records (1-min sampling) of 20 tide gauges and 8 air pressure stations in this region for the period of January 14–17, 2022. On the Russian coast, the highest waves, with a trough-to-crest wave height of 1.3 m, were recorded at Malokurilskoe (Shikotan Island) and Vodopadnaya (the southeastern coast of Kamchatka). Using numerical simulation and data analysis methods, we were able to separate the oceanic “gravity” tsunami waves from propagating atmospheric pressure waves. In general, we found that on the outer (oceanic) coasts and the southern coast of the Sea of Okhotsk, oceanic tsunami waves prevailed, while on the coast of the Sea of Japan, oceanic and atmospheric tsunami waves had similar heights.

Assessment of the Dynamical Linkages and Flow Evolution Governing Multiple Extreme Weather Events over Western North America in February 2019

Abstract We present an extended case study analysis based on observed extreme weather events (EWEs) and the planetary- and synoptic-scale variability of a persistent flow regime spanning the month of February 2019 across the North Pacific (NPAC) basin and western North America. The EWEs are clustered into two periods during February 2019: record cold and kona low conditions over Hawaii, lower elevation snow across Washington, and heavy AR-related rainfall in Southern California from 9 to 15 February; and heavy snow in Arizona and Oregon and heavy rainfall in Northern California from 21 to 28 February. From a weather regime perspective, the NPAC flow was dominated by a persistent ridge around 150°W, a retracted NPAC jet stream, repeated western NPAC (WPAC) cyclogenesis events, and frequent positively tilted troughs in the eastern NPAC and over western North America. Dynamically relevant features on the subseasonal-to-seasonal (S2S) time scale include a slowly propagating MJO signal in phases 6 and 7, a rapid NPAC jet retraction around 9 February, and subsequent eastward extension toward a climatological jet position around 21 February. On synoptic time scales, Rossby wave breaking on the southern flank of the NPAC jet and within the aforementioned persistent ridge led to the kona low formation and many of the positively tilted troughs responsible for the extreme precipitation events. In addition, frequent cyclogenesis west of the date line helped to maintain the persistent ridge strength and location through favorable heat and vorticity fluxes. The chronology and complex linkages between these aforementioned features and mechanisms are explained in depth in this paper. Significance Statement This study identified several extreme cold, rain, and snow events across the western contiguous United States and Hawaii, showed how these events are all connected to a persistent weather pattern upstream over the North Pacific basin, and identified key mechanisms for why the weather pattern was so persistent. Some of the physical mechanisms for keeping the weather pattern stagnant include anomalous convection within the tropics off the east coast of Asia, breaking waves in the atmosphere like waves breaking on a beach, and repeated cyclone development off the coast of Russia and Alaska. We hope that the results of this paper encourage others to look for similar mechanisms for similar stagnant weather patterns in a more holistic manner.

Two new species of Callophyllis (Rhodophyta, Kallymeniaceae) from the Russian Pacific coast

ABSTRACT Seven species of Callophyllis have been known off the Pacific coast of Russia; hovewer, molecular data have been obtained only for three species. In this study we re-examined the genus along the Russian Pacific coast using a comparative morphological study and molecular analyses based on rbcL and nrLSU. Five genetic species were identified on the Russian coast based on phylogenetics and species delimitation (ASAP and p-distance) analyses; while C. beringensis, C. papulosa and C. platyna were outscore of the analyses. The results of the molecular analyses uncovered one undescribed species, which we named C. selivanovae sp. nov. The divergence between this species and other species of the genus varied from 1.16% to 5.66%, while intraspecific divergence in the genus was in a range of 0.00%–0.22%. In phylogenetic trees C. selivanovae was recognized as sister to a diverse clade including C. thompsonii, C. beringensis, C. violacea, C. flabellulata and C. variegata from the Pacific coast of Canada. Callophyllis selivanovae from the southeastern coast of Kamchatka is morphologically close to C. beringensis, described from St. Paul Island (Bering Sea); the two species differ in features of branching, shape and size of the terminal branches. We propose a new name, C. perestenkoae sp. nov., for the algae previously listed in the Russian flora as ‘C. flabellata’. Pacific specimens assigned to C. perestenkoae differ from C. flabellata from the type locality (Atlantic, France) in having irregular branching, thicker apical branches, and smaller cystocarps. We also filled in the gaps in the description of C. radula for which procarp and tetrasporangia are described herein for the first time.

Impacts of Arctic Sea Fog on the Change of Route Planning and Navigational Efficiency in the Northeast Passage during the First Two Decades of the 21st Century

Under the background of climate change, the Northeast Passage’s navigability is on the rise. Arctic sea fog significantly influences navigational efficiency in this region. Existing research primarily focuses on routes accumulating the lowest distance, neglecting routes with the lowest time and sea fog’s influence on route planning and navigational efficiency. This study compares the fastest and shortest routes and analyzes Arctic sea fog’s impact on the Northeast Passage from June to September (2001–2020). The results show that coastal areas are covered with less sea ice under notable monthly variations. Sea fog frequency is highest near coasts, declining with latitude. September offers optimal navigation conditions due to minimal ice and fog. When only sea ice is considered, the fastest route is approximately 4 days quicker than the shortest. The shortest route has migrated towards the higher latitude over two decades, while the fastest route remains closer to the Russian coast. Adding the impact of sea fog on the fastest route, the speed decreased by 30.2%, increasing sailing time to 45.1%. The new fastest route considering both sea ice and sea fog achieved a 13.9% increase in sailing speed and an 11.5% reduction in sailing time compared to the original fastest route.

Morphological and molecular investigations shed light on diversity and distribution of Palmariaceae in the north-western Pacific

ABSTRACT Traditional morphology-based investigations of the red algal genera Devaleraea and Palmaria (Palmariaceae, Rhodophyta) fail to provide accurate accounts of diversity and distribution for species from the Russian coast of the north-western Pacific. Consequently, there is much disagreement and taxonomic uncertainty regarding several species. To resolve these issues we conducted a molecular-assisted investigation that included a DNA barcode survey (COI-5’) and multilocus (COI-5’, cob, psaA, ITS) phylogenetic analyses. Our analyses indicate that diversity was previously underestimated for the Devaleraea/Palmaria complex. We describe three additional species of Devaleraea: D. sakhalinensis sp. nov., D. kussakinii sp. nov. and D. urupiana sp. nov. We consider D. titlyanoviorum to be an alga with abundant proliferations from the margins, branching to several orders, that is known only from Kunashir Island. Algae from Sakhalin Island and the mainland coast of the Sea of Japan previously identified as D. titlyanoviorum are described here as D. sakhalinensis. We confirmed that the genus Palmaria is not monotypic. It includes at least two species: P. palmata in the North Atlantic and P. moniliformis in the north-western Pacific. We expand the known ranges of D. callophylloides, D. mollis and P. hecatensis in the north-western Pacific southwards and find that D. stenogona is confined to the northern part of the Sea of Japan. The distribution patterns of species of the genera Devaleraea and Palmaria are discussed in relation to the oceanography of the north-western Pacific. HIGHLIGHTS Three new species of the genus Devaleraea are proposed. The genus Palmaria is not monotypic and includes at least two species, P. moniliformis and P. palmata.

INVASIONS OF NEW MORPHOTYPES OF <i>CORBICULA FLUMINALIS </i>AND <i>CORBICULA FLUMINEA</i> (BIVALVIA: CORBICULIDAE) TO THE BASIN OF THE DAGESTAN REGION OF THE CASPIAN SEA

The article reports the discovery of populations of Corbicula mollusks in the south of the European part of Russia (N 43°, E 47°). Representatives of the genus Corbicula are included in the 100 most actively spreading invasive species. The aim of the study was to identify species and morphotypes in the Caspian Sea basin. For the first time on the territory of the Russian coast of the Caspian Sea at the mouth of the Sulak River in November 2019, 2 live specimens of the new morphotype B/Rlc Corbicula fluminea (Eastern corbicula, Asian Clam) (O.F. Müller, 1774) were found. In November 2021, 26 live individuals of the A/R C. fluminea morphotype were found in the Yuzbash-Sulak reservoir; 13 individuals of the A/R morphotype and 90 specimens of the C/S Corbicula fluminalis (O.F. Müller, 1774) morphotype in the Prisulak canal were found. A study of the morphometric parameters of the shells showed that the corbicules found belonged to different morphotypes, with well-distinguishable conchiological signs. The data obtained expand the understanding of the morphological variability of corbicules. A study of the species and size-age composition of populations was carried out. It was revealed that C. fluminea and C . fluminalis discovered on the Dagestan coast were new species and morphotypes of corbicules for the Russian sector of the Caspian Sea. The studied samples were dominated by mollusks of size and age groups corresponding to the age from 1.5 to 3 years, which indicated a recent settlement into a new reservoir for them. The populations of C. fluminalis studied from 2017 to 2021 were dominated by mollusks aged 5-6 years, which indicated an earlier introduction of this species. High physiological tolerance combined with different breeding strategies of the representatives of the genus Corbicula give grounds to assume a high probability of their successful naturalization in estuarine and freshwater ecosystems of the Dagestan region of the Caspian Sea.

Summer net community production in the northern Chukchi Sea: Comparison between 2017 and 2020

The Arctic Ocean environment is drastically changing because of global warming. Although warming-induced processes, such as the decrease in sea-ice extent and freshening of the surface layer, have the potential to alter primary production, the changes that will likely occur in their production and their mechanisms are still poorly understood. To assess the potential changes in net community production, which is a measure of biological carbon pump, in response to climate change, we observed the O2/Ar at the surface of the northern Chukchi Sea in the summers of 2017 and 2020. The net community production (NCP) estimates that we derived from O2/Ar measurements were largely in the range of 1 – 11 mmol O2 m-2 d-1 in the northern Chukchi and Beaufort Seas, close to the lower bounds of the values in the global oceans. The average NCP of 1.5 ± 1.7 mmol O2 m-2 d-1 in 2020 was substantially lower than 7.1 ± 7.4 mmol O2 m-2 d-1 in 2017, with the most pronounced decrease occurring in the ice-free region of the northern Chukchi Sea; the NCP of the ice-free region in 2020 was only 12% of that in 2017. The decrease in NCP in 2020 was accompanied by a lower salinity of > 2, which resulted in shallower mixed layer depths and stronger stratification. We speculated that the anomalously low pressure near the east Russian coast and the lack of strong winds contributed to the strong stratification in 2020. With a continuing decrease in the extent of sea ice, the northern Chukchi Sea will likely experience earlier phytoplankton blooms and nitrate exhaustion. Unless winds blow strong enough to break the stratification, the biological pump in late summer is likely to remain weak.

The genus Schizymenia (Nemastomatales, Rhodophyta) on the Russian coast of the northwest Pacific and description of S. tamarae sp. nov

ABSTRACT We analysed rbcL and COI sequence data of specimens of Schizymenia from the Sea of Okhotsk and Sea of Japan. Our results revealed a new species of Schizymenia, S. tamarae sp. nov., from the northwestern Sea of Japan. This species is distinct based on shape and the position of glandular cells. Morphological and genetic analyses confirmed that the previously described S. jonssonii is a synonym of S. dubyi var. palmata, which was originally described from the Kuril Islands. The latter taxon was synonymized with Neoabbottiella valentinae. We verified the synonymy of the three names and the affinity of the taxon with the genus Schizymenia. Since the name N. valentinae has priority at the rank of species we propose Schizymenia valentinae comb. nov. The only species of Schizymenia currently known to occur along the Russian coast are S. valentinae and S. tamarae. Schizymenia valentinae is distributed along southeastern Kamchatka, on the Commander Islands and Kurile Islands, and S. tamarae is known only from the Sea of Japan, where it occurs from Olga Bay to Peter the Great Bay on the Russian coast, and in Japan.

Development of Transport Accessibility and Transport Connectivity of the Black Sea Coast to Increase Mobility of Population and Develop Tourism

Based on the analysis of the route network of railway transport, airports and road traffic, the article provides an assessment of transport accessibility of the resorts of the Black Sea coast aimed at increasing mobility of population and develop tourism The structure of the tourist flow is considered in the context of the modes of transport. More than 50 % of tourists come to the Black Sea coast of Russia by their own cars, which indicates insufficient use of air transport and leads to an excessive load on the highways and the ecology of Kuban and Krasnodar region. Polls have shown that the main reasons for the use of road transport by tourists are the lack of direct air transport flights from some major cities in Russia and insufficient transport connectivity within the Black Sea coast. The article defines the directions for opening of new domestic routes from three regional airports. To solve the problem of transport connectivity, it is proposed to develop maritime traffic using hydrofoils, which will increase the mobility of tourists within the coast area and attract additional tourist flow.

Yacht Tourism on the Azov-Black Sea Coast of Russia as a Factor of Tourist Attractiveness of the Region

Introduction. The relevance of this considered scientific problem is due to the need to assess the recreational preferences of potential consumers of yachting services as a factor of tourist attractiveness and active promotion of the region. The purpose of the article is to determine the prospects for the development of yacht tourism on the Azov-Black Sea coast of Russia on the basis of the conducted analysis, which reflects the tourist attractiveness of the region in modern conditions. Materials and Methods. The authors analyzed panel statistics of the charter website 2Yachts, the informational and analytical agency SeaNews, the international broker of motor yachts Worldmarine, PKF International. To study the trends in the development of yacht tourism on the Azov-Black Sea coast of Russia, a number of indicators of the state of the yacht tourism industry of individual European countries have been studied, an investment project to create a network of marinas in the Republic of Crimea and the Krasnodar Territory has been considered. Results. The consumption preferences of clients in yacht tourism services on the Azov-Black Sea coast are revealed, the state of the yachting infrastructure of the region is assessed, the prospects for the development of yachting in the sea area of the Krasnodar Territory as a factor of tourist attractiveness of the region are outlined. The Azov-Black Sea coast of Russia has a significant potential for the development of yacht tourism (natural, socio-economic, cultural and historical resources). The development of yacht tourism should be carried out taking into account consumption preferences according to three basic criteria when choosing a yacht tour in the waters of the Azov and Black Seas – price, excursion program and tourist service. Discussion and Conclusion. The modernization of the yacht infrastructure and the popularization of yachting will contribute to the additional development of the tourism industry and the tourist attractiveness of the region, and will also raise yacht tourism to a new international level. The results of the study can become the basis for the development of a strategy for the creation and promotion of a tourist product for potential yachting customers at the regional level, and are also taken into account in the development of programs of integrated tourist services.

A revision of the red algal genus Ahnfeltia on the Russian coast of the North Pacific

ABSTRACT Until recently, three species of the genus Ahnfeltia were recorded from the Russian Pacific coast: A. fastigiata, A. plicata and A. tobuchiensis. A morphological analysis and DNA-barcoding of Ahnfeltia have revealed another species occurring in this area, A. borealis. The endemic taxon of this region, A. tobuchiensis, is conspecific with A. fastigiata and should be reduced to the varietal level, A. fastigiata var. tobuchiensis, as was previously suggested by Maggs et al. The occurrence of A. plicata in the Northwest Pacific requires confirmation by molecular and morphological data.

Satellite-Observed Chlorophyll-a Concentration Variability in the East Sea (Japan Sea): Seasonal Cycle, Long-Term Trend, and Response to Climate Index

In this study, to determine the spatiotemporal variability of satellite-observed chlorophyll-a(Chl-a) concentrations in the East Sea (Japan Sea, EJS), monthly composite images were generated via noise processing using Level-2 MODIS Chl-adata from 2003 to 2020. Harmonic analysis was performed on time-series Chl-adata to present the spatial distribution of seasonal and intraseasonal variability with 1–4 cycles per year. In the EJS, seasonal cycles contributed less than approximately 30% to the total variance in Chl-avariability, indicating the existence of dominant interannual variability. Analysis of the temporal trend in Chl-aconcentrations showed that they increased (< 0.06 mg m–3yr–1) in most of the EJS over almost two decades (2003–2020). In recent years, in the areas showing positive trends in Chl-a, it tended to increase with time, especially in the northern part of the EJS. As a result of examining the trend associated with the physical environment that affects the long-term trend in Chl-aconcentrations, sea surface temperature (SST) trends were mostly increased. The wind speeds showed a characteristic strengthening trend in the northeastern part of the EJS and the North Korean coast. Long-term changes in wind direction indicated strengthening of the northerly wind components on the Russian coast and the westerly components on the eastern coast of the Korean Peninsula. These wind changes were closely related to the Arctic Oscillation (AO) index variability in relation to the recent warming of the Arctic Ocean. When the AO index was greater than 1, the wind speed tended to be weakened and the SSTs showed a tendency to increase. This led to general increasing responses in Chl-aconcentrations during positive AO. The summer SST anomaly revealed an inverse relationship between higher positive values during the La Niña period and lower ones during the El Niño period. When the amplitude of MEI (Multi-variate ENSO Index) was high (| MEI| > 1), the SST anomaly indicated an inverse correlation with the Chl-aconcentration anomaly in the EJS. This study demonstrated the regional effects of climate change on Chl-avariability in the EJS in response to tropical–subtropical and arctic–subarctic interactions between ocean and atmospheric variations.

Highly Active Ice-Nucleating Particles at the Summer North Pole.

The amount of ice versus supercooled water in clouds is important for their radiative properties and role in climate feedbacks. Hence, knowledge of the concentration of ice‐nucleating particles (INPs) is needed. Generally, the concentrations of INPs are found to be very low in remote marine locations allowing cloud water to persist in a supercooled state. We had expected the concentrations of INPs at the North Pole to be very low given the distance from open ocean and terrestrial sources coupled with effective wet scavenging processes. Here we show that during summer 2018 (August and September) high concentrations of biological INPs (active at >−20°C) were sporadically present at the North Pole. In fact, INP concentrations were sometimes as high as those recorded at mid‐latitude locations strongly impacted by highly active biological INPs, in strong contrast to the Southern Ocean. Furthermore, using a balloon borne sampler we demonstrated that INP concentrations were often different at the surface versus higher in the boundary layer where clouds form. Back trajectory analysis suggests strong sources of INPs near the Russian coast, possibly associated with wind‐driven sea spray production, whereas the pack ice, open leads, and the marginal ice zone were not sources of highly active INPs. These findings suggest that primary ice production, and therefore Arctic climate, is sensitive to transport from locations such as the Russian coast that are already experiencing marked climate change.

Organotin compounds (OTs) in surface sediments, bivalves and algae from the Russian coast of the Barents Sea (Kola Peninsula) and the Fram Strait (Svalbard Archipelago).

Organotin pollution in components of benthic ecosystems was investigated in 2019 in the Barents Sea (South shore, Kola Peninsula) and the Fram Strait (Icefjord, Svalbard Archipelago). Six species of organotin compounds (OTs), including monobutyltin, dibutyltin, tributyltin, tetrabutyltin, triphenyltin and tricyclohexyltin, were measured in the surface sediments, bivalve molluscs (Ciliatocardium ciliatum, Macoma calcarea, Chlamys islandica) and macrophyte algae (Saccharina latissima, Palmaria palmata, Ulvaria obscura, Fucus serratus, Fucus distichus). The results obtained showed moderate contamination of the studied samples with OTs. The total content of six tin compounds was in the ranges 35-139ngg-1, 13-108ngg-1 and 2.9-75ngg-1 (dry weight) in the samples of sediments, bivalves and algae, respectively. In most cases, the concentrations of tributyltin in bottom sediments and mollusc tissues did not exceed the established international regulations. The degradation indices analysis of butyl tin derivatives indicated the active transformation of tributyltin and tetrabutyltin in bottom sediments and macrophyte algae and the accumulation of these compounds in the soft tissues of molluscs. The sediment and mollusc concentrations of OTs measured in this study were comparable to those reported for other areas of the Arctic region.

Regulation of Arctic Shipping in Canada and Russia

As Arctic navigation increases and states work, both at the international and the domestic level, at ensuring legal readiness, this article takes a closer look at regulation of Arctic Shipping in Canada and Russia. The analysis first focuses on the current domestic regimes that have developed over the past decades. It highlights that dissimilar political, economic and environmental contexts have shaped not only different shipping patterns off the Canadian and Russian coasts, but also dissimilar coastal state approaches that do not seem to converge noticeably under the influence of the Polar Code. The analysis then turns to challenges that lay ahead as existing regimes could be called into question due to receding ice cover and may need to adapt to evolving shipping patterns and technological innovations.

Роль Петра Великого в освоении Русской Арктики

Aim. The purpose of the article is to study Peter the Great’s plans for the Russian Arctic and analyze the development of the Arctic coast of Russia in the Peter the Great’s era.Methodology. The study is based on the authors’ work with sources, as well as the generalization of data given in the Russian historical literature. The article uses problem-chronological, historicalsystematic and comparative-historical methods.Results. The study of the development dynamics of the Arctic coast of the Russian Empire under Peter I showed that at that time there was a transition from a resource scheme to the logistics one. New proofs of the «Japanese vector» of Peter the Great’s aspirations and the organization of the search for the Northeast Passage are presentedResearch implications. The concept of three factors of domestic development of the Arctic was created: resource, logistics and military-strategic. According to the authors, it is more productive than the idea of waves of Russian colonization of Siberia (fur, metal and agrarian) which exists in historical literature today. The materials of the article can be used in the development of special courses and special seminars on the period of Peter the Great’s transformations, the history of the Russian Arctic, the history of geographical discoveries.

Export of Transport Services: Russian Far East

The article analyzes the dynamics of the key components of the export of transport services at the national and regional levels. It is shown that despite the negative impact of restrictions during the spread of the pandemic in 2019-2020, there is an increase in the export of transport services of the Russian Federation. The growth of the indicator is due to the increase in revenues from freight transportation. The regional cross-section is presented on the example of the Russian Far East. At the macro-regional level, the share of transport in the total export of services is significantly (1.8 times) higher than the national average. The main contribution to the formation of the indicator of the macroregion is made by Primorsky Krai (7.5%). The key seaports of the Pacific coast of Russia are located here. Three directions for the development of the export of transport services in the Far East are presented: 1) servicing export-import flows outside the national territory, 2) transit traffic, 3) participation in the international market of transport services. For each direction, the growth opportunities and restrictions on the export of transport services were assessed. With the use of comparative analysis methods, it is argued that the most promising is the service of cargo flows of the national economy. Prospects are related, among other things, to the implementation of the Northern Sea Transport Corridor project and the formation of a system of reference seaports for Arctic routes in the macroregion. It is shown that transit traffic will not play a significant role in the growth of exports of transport services in the Far East. The negative impact of infrastructural and economic factors on the competitiveness of international transport corridors passing through the territory of the east of the country has been revealed. The limitations of the direct participation of the transport complex of the Far Eastern Federal District in the international market are argued, which include features of the structure of the economy and insufficient development of the elements of the transport complex. The results of the work can serve as a basis for developing measures to develop the export of transport services.

Two branchial pathological conditions, nuclear hypertrophy and abnormal epithelial proliferation, in Mya arenaria from northwest Russian coasts.

Histopathological analysis of soft-shell clams Mya arenaria collected from 2 northwest Russian locations disclosed high prevalence of 2 pathological gill conditions. One involved the occurrence of more or less extended gill areas in which the branchial filaments showed hyperchromatic (basophilic) epithelium with some hypertrophied nuclei, which were considered presumptive signs of viral infection. Another pathological condition involved abnormal proliferation of the branchial epithelium, which lost the main differential features of the normal branchial epithelium (ciliated and simple cell layer structure), becoming non-ciliated, pseudostratified or stratified hyperchromatic epithelium with abundant mitotic figures and frequent apoptotic cells. The most complex cases involved loss of the normal branchial filament architecture, which was replaced with tumour-like growths consisting of branching, convoluted epithelial projections with a connective stroma. Images suggesting migration (invasion) of cells from the abnormally proliferating epithelium to the subjacent connective tissue, which would involve malignancy, were observed in one individual. The occurrence of both pathological conditions in clams from both locations and their co-occurrence in one clam suggest the possibility of a common, possibly viral, aetiology. Furthermore, the high prevalence of the abnormal proliferative disorder in non-polluted areas suggests an infectious aetiology. Additional studies are needed to assess a viral aetiology for the nuclear hypertrophy and/or the abnormal epithelial proliferation as well as the malignancy of the latter condition.

The Projects of the North Siberian Steel Highways as a Promising Transport Cooperation between the World's Leading Economies

The Socio-economic development of the Russian Arctic is impossible without the creation of an integrated transport infrastructure of the region, including water: sea and river, land: road and rail, as well as aviation communications. For longer than a century and a half, specialists, politicians, entrepreneurs, and enthusiasts are trying to solve the problem. Dozens of future transportation projects are nominated. The vast territory of polar Urals, Northern Siberia, the Far East, the Russian coast of the Arctic Ocean, channels of the Siberian rivers are explored. Thousands of miles of communications are laid, but a single transport network of the Russian Arctic is still not created. The core of the transport infrastructure of the region can be the Transpolar railway, the all-season line-the link of the existing Trans-Siberian railway with branches, Siberian roads, the Northern Sea Route, navigable Siberian rivers and regional airports. The completion of this ambitious project will increase the capacity of the Russian segment of the Asia-European transport corridor, expand the socio-economic importance of the Russian Arctic, strengthening the strategic importance of Russia.

Primary productivity and phytoplankton community structure in surface waters of the western subarctic Pacific and the Bering Sea during summer with reference to bloom stages

The western subarctic Pacific and adjacent Bering Sea are recognized as one of the most productive regions supported by spring diatom bloom among the world’s oceans. Yet, phytoplankton growth and photosynthesis are often suppressed during summer. Little is known about factors controlling the summer primary productivity and phytoplankton community structure in the western subarctic Pacific and the Bering Sea, especially along the Russian coast extending from the Kuril Islands to the Gulf of Anadyr. A total of 24 stations belonging to two cruises conducted in June 2014 and August 2018 was categorized into three groups using hierarchical cluster analysis for physical properties such as seawater temperature, salinity, and mixed layer depth. Based on the biogeochemical characteristics of each cluster, we defined clusters 1, 2, and 3 as bloom, post-bloom, and pre-bloom conditions, respectively. Cluster 1, observed near the Kuril Islands and the Kamchatka Peninsula, was characterized by nutrient-rich cold water that supported the predominance of diatoms. Nutrient-depleted warm waters associated with shallow mixed-layer and small diatom populations were grouped into cluster 2, distributed in the Gulf of Anadyr and near the Kamchatka Peninsula. The deepest mixed layer depth was found in cluster 3, accompanied by the low proportions of diatoms. The spatial distribution of cluster 3 showed broad geographical coverages extending from the Kuril Islands to the Aleutian Basin. Thus, this study identified the relationships between summer primary productivity, phytoplankton community composition, and environmental variables in surface waters of the subarctic Pacific along the Russian coast. Overall, the present study addressed the shortcoming of in situ data in phytoplankton communities and environmental variables in the western subarctic Pacific and the Bering Sea.