Climate-induced changes contribute to the thawing of ice-rich permafrost in the Arctic, which leads to the release of large amounts of organic carbon into the atmosphere in the form of greenhouse gases, mainly carbon dioxide and methane. Ground ice constitutes a considerable volume of the cryogenically sequestered labile dissolved organic carbon (DOC) subjected to fast mineralization upon thawing. In this work, we collected a unique geochemical database of the ground and glacier ice comprising the samples from various geographic locations in the Russian Arctic characterized by a variety of key parameters, including ion composition, carbon-bearing gases (methane and carbon dioxide), bulk biogeochemical indicators, and fluorescent dissolved organic matter (DOM) fractions. Our results show that interaction with solid material—such as sediments, detritus, and vegetation—is likely the overriding process in enrichment of the ground ice in all the dissolved compounds. Terrigenous humic-like dissolved organic matter was predominant in all the analyzed ice samples except for glacier ice from Bolshevik Island (the Severnaya Zemlya archipelago) and pure (with low sediment content) tabular ground ice from western Yamal. The labile protein-like DOM showed no correlation to humic components and was probably linked to microbial abundance in the ground ice. The sum of the fluorophores deconvoluted by PARAFAC strongly correlates to DOC, which proves the potential of using this approach for differentiation of bulk DOC into fractions with various origins and biogeochemical behaviors. The pure tabular ground ice samples exhibit the highest rate of fresh easily degradable DOM in the bulk DOC, which may be responsible for the amplification of permafrost organic matter decomposition upon thawing.

The study of massive ices is of interest both for the purposes of paleogeographic reconstructions, and for solving engineering and geocryological problems. Despite the widespread distribution of massive ice beds in the cryolithozone, the problem of spatial identification of them and mapping has not yet been resolved, which is mainly due to the difficulty of determining and understanding the processes of their formation. The paper presents the results of studying the methane content as a genetic trait in massive ice beds along the coast of Eastern Chukotka. In 2016-2022, our team studied variations in the methane content in 4 massive ice beds and host deposits using the "headspace" method. The CH4 concentration in ice and air bubbles ranged from 1 to 1582 ppmv, which made it possible to suggest the genesis of each bed and compare it with previously proposed hypotheses of their formation based on the earlier made cryolithological and oxygen isotope analyses. The study has confirmed the intra-ground (median methane concentration of 432 ppmv) and buried (2 ppmv) genesis for two beds. For the third one, the issue of its genesis remained debatable, and in the fourth bed, the obtained results have thrown doubt on the previous hypothesis about the intra-ground genesis of ice, since the recorded methane concentration was found to be close to the atmospheric one. Despite the limitations of the "headspace" method shown in the paper, it was manifested as the adequate way for the field studies when transportation of frozen samples to the laboratory is impossible.

The climate changes taking place in the Arctic are expressed in the increase in extreme values, as well as in a wide range of processes of degradation of permafrost, the state of which, being sensitive to climate change, causes the activation of rapidly proceeding exogenous processes. To predict the climate of the YaNAO for the middle of the 21st century, data from 42 models of the CMIP6 project were used. The temperature in January will increase by about 3.5 (on the coast of the Kara Sea even by 4.5°C), and in July by ~2.5°C everywhere. The 5 and 95% quantiles will increase by 3 and 4.5°С in January and by 2 and 3°С in July, respectively. Monthly precipitation will increase by an average of 10% in January and remain unchanged in July. The 95% quantile values will increase by 30% and 10% in January and July, respectively. The number of days with frost will be reduced. Warming in combination with an increase in precipitation will lead to an increase in the activity of avalanches, snow flows and mudflows on the eastern slopes of the Urals, as well as on the characteristics of landslides, abrasion, suffusion, erosion, thermokarst, and solifluction. Climate-dependent sectors of the economy should be ready for predictable changes in the natural environment.

The environmental conditions of the Arctic are vulnerable to the effects of climate change. We focus on the territory of the Yamalo-Nenets Autonomous Okrug (YaNAO). The objective of this study is to project mid-21st century climate-driven changes in the state of climate and the natural environment in the YaNAO. For this purpose, the CMIP6 data models with the climate change scenario SSP5-8.5 were used. Climate change directly affects the statistics of extreme events and climatically driven phenomena, such as frosts and thaws, as well as avalanches and slush flows. Climate change causes changes in the Arctic environment, primarily due to permafrost degradation, leading to important modifications in events such as mudflows, cryogenic landslides, abrasion, erosion, suffusion, frost heave, solifluction, thermokarst, and others. In some cases, the intensity and area of these processes increase, such as heaving processes and thermokarst becoming more active by 2050. In other cases, the solifluction processes decrease in the south part of the YaNAO due to the discontinuous or sporadic permafrost distribution. Projected climatic changes will inevitably lead to the restructuring of the geosystems in YaNAO, creating risks for infrastructure in economically active territories.

Climate change observed in the Arctic affects all components of the natural environment, including the state of permafrost. The purpose of this study is to quantify the response of permafrost in various landscapes to changing climatic parameters. The results of long-term field observations (1978-2021) of the thermal regime of permafrost on the Western Yamal are presented. Along with the increase in mean annual air temperatures, the mean annual ground temperature over the past 43 years has increased by 1.5-2.2°C. The maximum increase of permafrost temperature values is observed on flat and polygonal tundra, the minimum increase is typical for flooded lake basins. A decrease in the annual permafrost temperature amplitude was revealed. That is caused by a rapid increase in the air temperature of the cold period, an increase in the snow thickness and an increase in soil moisture in the active layer. The shrinking in ground temperature amplitude at a depth of 5 m is 0.5-3.6°C. A trend of reducing depth of zero annual amplitude from 12-18 m (1980) to 13-16 m (2021) has been revealed.

In recent decades, acceleration of coastal erosion has been observed at many key sites of the Arctic region. Coastal dynamics of both erosional and accretional stretches at Kharasavey, Kara Sea, was studied using multi-temporal remote sensing data covering the period from 1964 to 2022. Cross-proxy analyses of the interplay between coastal dynamics and regional (wave and thermal action) and local (geomorphic and lithological features; technogenic impact) drivers were supported by cluster analysis and wind–wave modelling via the Popov–Sovershaev method and WaveWatch III. Ice-rich permafrost bluffs and accretional sandy beaches exhibited a tendency towards persistent erosion (−1.03 m/yr and −0.42 m/yr, respectively). Shoreline progradation occurred locally near Cape Burunniy (6% of the accretional stretch) and may be due to sediment flux reversals responding to sea-ice decline. Although the mean rates of erosion were decreasing at a decadal scale, cluster analysis captured a slight increase in the retreat for 71% of the erosional stretch, which is apparently related to the forcing of wind–wave and thermal energy. Erosional hotspots (up to −7.9 m/yr) occurred mainly in the alignment of Cape Kharasavey and were predominantly caused by direct human impact. The presented study highlights the non-linear interaction of the Arctic coastal change and environmental drivers that require further upscaling of the applied models and remote sensing data.

The retreat rates of Arctic coasts have increased in recent decades at many sites, and an essential part of coasts considered accumulative before have turned erosional due to global climate changes and construction in the coastal zone. In this paper, we study a 7 km long coastal section of the western Gydan Peninsula in a new construction area. Based on the interpretation of multi-temporal satellite imagery, we assessed coastal dynamics in distinct periods from 1972 to 2020. We analyzed the geological structure of the coast as well as changes in hydrometeorological parameters with time, and considering the human impact, we proposed the main drivers of spatial and temporal variations of coastal dynamics. The studied low-lying sandy accumulative marine terrace was more or less stable in the period before construction (1972–2014). However, with the area’s development, the coast dynamics changed drastically: in 2014–2017, three-quarters of the studied area experienced retreat, and the average retreat rate amounted to 5.8 m/yr, up to 28.5 m/yr near the construction sites. We relate this coastal erosion intensification to human impact combined with the growth of hydrometeorological forcing. Although coastal erosion slowed down after 2017, the retreat trend remained. In the coming years, with Arctic climate warming, erosion of the studied coast will continue.

About half of the Russian Arctic coastline consists of ice-rich permafrost deposits. The dynamic response of this coastal type is forced mainly by the change of natural environment caused by the development of global warming. Rising temperatures are altering the arctic coastline and much larger changes are projected to occur during this century as a result of reduced sea ice, thawing permafrost. Less extensive sea ice creates more open water, allowing stronger wave generation by winds, thus increasing wave-induced erosion along Arctic coast. Technogenic impact can also influence the rates of their erosion, causing rapid retreat. For key areas on the coasts of the Russian Arctic Seas, connections between climate change, human activity and coastal erosion have been analyzed.

Coastal erosion in the Arctic has numerous internal and external environmental drivers. Internal drivers include sediment composition, permafrost properties and exposure which contribute to its spatial variability, while changing hydrometeorological conditions act as external drivers and determine the temporal evolution of shoreline retreat. To reveal the relative role of these factors, we investigated patterns of coastal dynamics in an enclosed bay in the southwestern Kara Sea, Russia, namely the Gulf of Kruzenstern, which is protected from open-sea waves by the Sharapovy Koshki Islands. Using multitemporal satellite imagery, we calculated decadal-scale retreat rates for erosional segments of the coastal plain from 1964 to 2019. In the field, we studied and described Quaternary sediments and massive ground-ice beds outcropping in the coastal bluffs. Using data from regional hydrometeorological stations and climate reanalysis (ERA), we estimated changes in the air thawing index, sea ice-free period duration, wind-wave energy and total hydrometeorological stress for the Gulf of Kruzenstern, and compared it to Kharasavey and Marre-Sale open-sea segments north and south of the gulf to understand how the hydrometeorological forcing changes in an enclosed bay. The calculated average shoreline retreat rates along the Gulf in 1964–2010 were 0.5 ± 0.2 m yr−1; the highest erosion of up to 1.7 ± 0.2 m yr−1 was typical for segments containing outcrops of massive ground-ice beds and facing to the northwest. These retreat rates, driven by intensive thermal denudation, are comparable to long-term rates measured along open-sea sites known from literature. As a result of recent air temperature and sea ice-free period increases, average erosion rates rose to 0.9 ± 0.7 m yr−1 in 2010–2019, with extremes of up to 2.4 ± 0.7 m yr−1. The increased mean decadal-scale erosion rates were also associated with higher spatial variability in erosion patterns. Analysis of the air thawing index, wave energy potential and their total effect showed that inside the Gulf of Kruzenstern, 85% of coastal erosion is attributable to thermal denudation associated with the air thawing index, if we suppose that at open-sea locations, the input of wave energy and air thawing index is equal. Our findings highlight the importance of permafrost degradation and thermal denudation on increases in ice-rich permafrost bluff erosion in the Arctic.

Электронный атлас «абразионной и ледово-экзарационной опасности прибрежно-шельфовой зоны Российской Арктики», созданный при поддержке Российского научного фонда, размещен в открытом доступе на платформе arcticcoast.ru. Атлас включает в себя серию обзорных и региональных карт, аналитических и фотоматериалов, наглядно иллюстрирующих распространение в Российской Арктике процессов, которые наибольшую опасность при строительстве инженерных сооружений в прибрежно-шельфовой зоне замерзающего моря: абразии и ледовой экзарации. Атлас может быть полезен широкому кругу специалистов, ученых и студентов, занимающихся вопросами освоения побережья и шельфа арктических морей России.

ABSTRACT Belova, N.G.; Novikova, A.V.; Günther, F., and Shabanova, N.N., 2020. Spatiotemporal variability of coastal retreat rates at Western Yamal Peninsula, Russia, based on remotely sensed data. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 367–371. Coconut Creek (Florida), ISSN 0749-0208. The work aims at estimating coastal retreat at Western Yamal from 1972 to 2016, when significant climate change occurred in the Arctic. One fourth of the Kara Sea coasts are collapsing cliffs composed of permafrost, i.e. thermoabrasional coasts. Although these coasts are bounded by sea ice for most of the year, they retreat with rates comparable to those of temperate latitudes, but only during the short ice-free period. Permafrost cliffs are not only eroded by waves; they also get destroyed by melting of the ground ice bounding the sediments (thermo-denudation). Arctic coasts are sensitive to climate change, as rising summer air temperatures lead to deeper thawing of frozen sediments, and longer ice-free periods extend the time of the wave impact on the coast. At Western Yamal, in the area of Kharasavey gas condensate field, the average long-term coastal retreat rate is 1.3 m/yr (1972-2016) for 5.9 km of the coastline, reaching mean annual rates of 3 m/yr in some areas. The greatest retreat rates are typical for coastal segments composed of permafrost with high ice content. Based on the analysis of multitemporal aerial and space images, the coastal retreat rates for four time periods between 1972 and 2016 were estimated. The retreat rates were brought into context with data on sediment composition and type (grain size, ice content, presence of massive ice), reconstructed evolution of hydrometeorological parameters and the history of economic development of Kharasavey area. Unlike other Kara Sea sites of coastal dynamics' monitoring, the strongest coastal retreat rates at Kharasavey were observed earlier in 1977-1988, when the hydrometeorological stress was low, implying vulnerability of the coasts to significant anthropogenic impact at the beginning of the gas field development.

Since the early 2000s, observations from 14 coastal permafrost sites have been updated, providing a synopsis of how changes in the Arctic System are intensifying the dynamics of permafrost coasts in the 21st Century. Observations from all but 1 of the 14 permafrost coastal sites around the Arctic indicate that decadal-scale erosion rates are increasing. The US and Canadian Beaufort Sea coasts have experienced the largest increases in erosion rates since the early-2000s. The mean annual erosion rate in these regions has increased by 80 to 160 % at the five sites with available data, with sites in the Canadian Beaufort Sea experiencing the largest relative increase. The sole available site in the Greenland Sea, on southern Svalbard, indicates an increase in mean annual erosion rates by 66 % since 2000, due primarily to a reduction in nearshore sediment supply from glacial recession. At the five sites along the Barents, Kara, and Laptev Seas in Siberia, mean annual erosion rates increased between 33 and 97 % since the early to mid-2000s. The only site to experience a decrease in mean annual erosion (- 40%) was located in the Chukchi Sea in Alaska. Interestingly, the other site in the Chukchi Sea experienced one of the highest increases in mean annual erosion (+160%) over the same period. In general, a considerable increase in the variability of erosion and deposition intensity was also observed along most of the sites.

Permafrost coasts make up roughly one third of all coasts worldwide. Their erosion leads to the release of previously locked organic carbon, changes in ecosystems and the destruction of cultural heritage, infrastructure and whole communities. Since rapid environmental changes lead to an intensification of Arctic coastal dynamics, it is of great importance to adequately quantify current and future coastal changes. However, the remoteness of the Arctic and scarcity of data limit our understanding of coastal dynamics at a pan-Arctic scale and prohibit us from getting a complete picture of the diversity of impacts on the human and natural environment. In a joint effort of the EU project NUNATARYUK and the NSF project PerCS-Net, we seek to close this knowledge gap by collecting and analyzing all accessible high-resolution shoreline position data for the Arctic coastline. These datasets include geographical coordinates combined with coastal positions derived from archived data, surveying data, air and space born remote sensing products, or LiDAR products. The compilation of this unique dataset will enable us to reach unprecedented data coverage and will allow us a first insight into the magnitude and trends of shoreline changes on a pan-Arctic scale with locally highly resolved temporal and spatial changes in shoreline dynamics. By comparing consistently derived shoreline change data from all over the Arctic we expect that the trajectory of coastal change in the Arctic becomes evident. A synthesis of some initial results will be presented in the 2020 Arctic Report Card on Arctic Coastal Dynamics. This initiative is an ongoing effort – new data contributions are welcome!

World tendency in partial substitution of fishmeal-based diet in feeding fish reared in aquaculture systems for plant proteins is caused by exhaustion of fishery resources. The use of products of fat-free soy processing in feeds has provoked troubles in salmonid health, in particular the onset of inflammation in the intestine. Numerous investigations devoted to the analysis of reasons for such negative consequences have attracted attention to the intestinal microbiota of fish. In this review, we analyze the studies on the effect of soy proteins in feed on the intestinal microbiota of salmonids.

Perennially frozen ground and sea ice are key constituents of permafrost coastal systems, and their presence is the primary difference between temperate and high-latitude coastal processes. These systems are some of the most rapidly changing landscapes on Earth and, in the Arctic, are representative of the challenges being faced at the intersection between natural and anthropogenic systems. Permafrost thaw, in combination with increasing sea level and decreasing sea-ice cover, exposes arctic coastal and nearshore areas to rapid environmental and social changes. Based on decadal timescales, observations in the Arctic indicate an increase in permafrost coastal bluff erosion and storm surge flooding of low-lying ice-rich permafrost terrain. However, circum-arctic observations remain limited and the factors responsible for the apparent increase in arctic coastal dynamics are poorly constrained. A better understanding of permafrost coastal systems and how they are responding to changes in the Arctic is important since a high proportion of Arctic residents live on or near coastlines, and many derive their livelihood from terrestrial and nearshore marine resources. An expanding industrial, scientific, and commercial presence in the Arctic Ocean will also require advanced knowledge about permafrost coastlines as terrestrial access points. Since the issues involved span political, cultural, geographical, and disciplinary borders, an international network focused on permafrost coastal systems in transition is needed. An integrative network focused on permafrost coastal systems is required to realize and address the scale and complexity of the processes, dynamics, and responses of this system to physical, ecological, and social change. A primary focus of such an effort would be guided by the fact that the issues and impacts associated with permafrost coastal systems in transition are far greater than any single institution or discipline is capable of addressing alone. Future permafrost coastal system dynamics will challenge conventional wisdom as the system enters a new state impacting human decision making and adaptation planning, cultural heritage resources and ecosystems, and likely resulting in unforeseen challenges across the Arctic.