Sources, fate and distribution of inorganic contaminants in the Svalbard area, representative of a typical Arctic critical environment-a review

Assessment of microbial communities from cold mine environments and subsequent enrichment, isolation and characterization of putative antimony- or copper-metabolizing microorganisms

Mining activities, even in arctic regions, create waste materials releasing metals and metalloids, which have an impact on the microorganisms inhabiting their surroundings. Some species can persist in these areas through tolerance to meta(loid)s via, e.g., metabolic transformations. Due to the interaction between microorganisms and meta(loid)s, interest in the investigation of microbial communities and their possible applications (like bioremediation or biomining) has increased. The main goal of the present study was to identify, isolate, and characterize microorganisms, from subarctic mine sites, tolerant to the metalloid antimony (Sb) and the metal copper (Cu). During both summer and winter, samples were collected from Finnish mine sites (site A and B, tailings, and site C, a water-treatment peatland) and environmental parameters were assessed. Microorganisms tolerant to Sb and Cu were successfully enriched under low temperatures (4°C), creating conditions that promoted the growth of aerobic and fermenting metal(loid) tolerating or anaerobic metal(loid) respiring organism. Microbial communities from the environment and Sb/Cu-enriched microorganisms were studied via 16S rRNA amplicon sequencing. Site C had the highest number of taxa and for all sites, an expected loss of biodiversity occurred when enriching the samples, with genera like Prauserella, Pseudomonas or Clostridium increasing their relative abundances and others like Corynebacterium or Kocuria reducing in relative abundance. From enrichments, 65 putative Sb- and Cu-metabolizing microorganisms were isolated, showing growth at 0.1 mM to 10 mM concentrations and 0°C to 40°C temperatures. 16S rRNA gene sequencing of the isolates indicated that most of the putative anaerobically Sb-respiring tolerators were related to the genus Clostridium. This study represents the first isolation, to our knowledge, of putative Sb-metabolizing cold-tolerant microorganisms and contributes to the understanding of metal (loid)-tolerant microbial communities in Arctic mine sites.

Impacts of anthropogenic activities and glacial processes on the distribution of chemical elements in Billefjord, Svalbard, Arctic

The Arctic region is undergoing rapid and extensive transformations due to global climate change. This study investigated the spatial distribution of 31 chemical elements in eight locations in Billefjord, Svalbard, Arctic, with varying degrees of anthropogenic and glacial influences. The west coast of Billefjord has experienced a greater historical anthropogenic impact, while the east coast has larger glaciers and shows less visible evidence of direct human impact. Over 450 topsoil samples collected in the west (abandoned mining town Pyramiden, and glacial valleys of Elsa, Ferdinand, Sven) and east coast of the fjord (glacial valleys of Ebba, Pollock, Ragnar and nearby the Nordenskiöld glacier). These samples were extracted and analyzed by ICP-OES. The results revealed complex distributions of elements among the locations. Nordenskiöld glacier area, along with other locations in the eastern part of the Billefjord, had significantly higher levels of most elements (20 out of 31; As, B, Ca, Cd, Co, Cr, Cu, K, Li, Mg, Mo, Sb, Se, Sn, Sr, Ti, Tl, U, V, Zr). In contrast, Ferdinand Valley and other locations on the western side of the fjord had the lowest mean concentrations of most elements (18 out of 31; B, Ca, Cu, Cd, K, Li, P, Mg, Mo, Sb, Se, Sn, Sr, Ti, Tl, U, V, Zr). These findings highlight the significant influence of glacial processes on the elemental composition of soils within the region. The meltwater flow originating from glaciers in the sampled valleys contributes to the local element load, while the loss of glacier mass is associated with decreased element concentrations within these valleys. These results underscore the complexity of element distribution in the study area and emphasize the necessity for continuous monitoring efforts in this unique and environmentally sensitive region.

Chemical element distribution in Arctic soils: Assessing vertical, spatial, animal and anthropogenic influences in Elsa and Ebba Valleys, Spitsbergen, Svalbard

The Arctic region is threatened by climate change and pollution caused by human activities which potentially influence the elemental concentrations available to and from the biota. To better understand this delicate balance, it is crucial to investigate the role of several factors. Therefore, we quantified the level of 43 chemical elements in soils from Elsa and Ebba Valleys, Petunia Bay, Spitsbergen, a region that has experienced lasting environmental impacts from historical mining activities. We evaluated the a) vertical sampling influence by examining the variation in element distribution between the soil upper and deeper layers, b) animal influence by verifying the role of native animals, particularly vertebrates, in introducing thought faeces elements to the soil and c) anthropogenic influence by studying the spatial geographical differences in element distribution based on the degree of human pressure between the valleys. Our analysis also includes data on soil organic matter (SOM) and mineral composition. Both valleys exhibited similar mineralogical composition, but Elsa Valley had higher concentrations of most analyzed elements compared to Ebba Valley. Despite the contribution of vertebrate feaces, no increase in element concentrations was observed in the animal-influenced soils. The sampled soil layers had similar chemical element profiles for most elements. SOM content tended to be higher in superficial soils and showed a strong positive correlation with most quantified elements. The higher concentrations in Elsa Valley reflect its past mining and mineral exploration, making this area more significantly impacted than Ebba Valley. Surprisingly, vertebrate animals do not appear to influence the concentrations of chemical elements or organic matter in soils. Our findings provide valuable insights into the legacy of past mining activities and mechanisms driving environmental change in the Arctic.

Trace metals in surface water of the Pechora River and its tributaries: Content, water quality and risks assessment (Arctic Ocean basin)

The article is devoted to the study of trace metals content in the Pechora River and its tributaries, which is the largest river in the Arctic Ocean basin. The study of physico-chemical properties of water showed aerobic conditions of low-mineralised water with pH values suitable for drinking water. Analysis of the content of trace metals has revealed that the main flow of Al, Mn, Co, Cu, Zn, V, As, Mg and Fe into the Pechora River comes from its tributaries. The average content of Cr, Mn, Cu, Zn, Pb, V, As, Mg and Fe in the water of the Pechora River delta was higher than for the main river channel, which indicates the transfer of a large mass of trace metals to the Barents Sea and the Arctic water ecosystem. For the studied river and tributaries, chronic pollution of the Pechora River with Al, Mn, Ba, Fe, Cu, U and Pb metals has adverse effects on waterborne organisms. The degree of contamination of natural waters by metals has been assessed using water quality indices (TMPI, TMEI, TMTI) and public health risks (HI and CR). Low contamination and weak toxicity of the Pechora River water has been determined, but serious contamination, toxicity and high non-carcinogenic risk of some of its tributaries have been observed. A high carcinogenic risk has been established for the consumption of all water sampled. Al, Ni, As, Fe, Mn, Cr, Cd, and Ba were found to be the highest priority contaminating trace metals. At present, contamination of the Pechora River and its tributaries with trace metals is formed under the influence of dissolution processes of rocks of the Ural Mountains, the Taminsky Ridge, underlying mineral deposits, permafrost degradation processes and glacier melting. Anthropogenic factors include oil and gas production and transportation.

Natural and anthropogenic radionuclides concentration with heavy metals analysis of the sediments collected around Novaya Zemlya

The Dispersal profile of the radioisotopes (226Ra, 232Th, 235U, 40K, 137Cs) along with potentially toxic elements (Cd, Co, Cr, Cu, Ni, Pb, V, Zn, and Hg) in the sediments around the Novaya Zemlya was determined. The task was fulfilled with the aid of HPGe gamma spectrometry, inductively coupled plasma optical emission spectroscopy, DMA-80 Direct Mercury Analysis System, X-ray diffraction and statistical tools. At most of the locations, the radionuclides activity was higher than the world average activity concentration for the respective nuclei, 40K being the most abundant. From all the potentially toxic elements detected, Cr and Ni were usually observed on higher levels compared to their background values, indicating the probability of the detrimental biological effects. Thus, the present situation at the studied area might be a threat to the neighboring marine life.

Novel Plasmid Carrying Mobile Colistin Resistance Gene mcr-4.3 and Mercury Resistance Genes in Shewanella baltica: Insights into Mobilization of mcr-4.3 in Shewanella Species

Shewanella species have been identified as progenitors of several clinically important antibiotic resistance genes. The aim of our study was to analyze Shewanella baltica strains isolated from the gut contents of wild Atlantic mackerel (Scomber scombrus) for the presence of both known and novel variants of antibiotic resistance genes (ARGs), using Illumina-based whole-genome sequencing (WGS). Thirty-three S. baltica strains were isolated from Atlantic mackerel collected in the northern North Sea. WGS revealed the presence of several new variants of class C and class D beta-lactamases. Nearly 42% (14/33) of the strains carried the mobile colistin resistance gene mcr-4.3. To understand the genetic context of mcr-4.3, we determined the complete genome sequence of strain 11FHM2, using a combination of Oxford Nanopore- and Illumina-based sequencing. The complete genome sequence is 5,406,724 bp long, with one contig representing a chromosome of 5,068,880 bp and three contigs representing novel plasmids (pSBP1, 194,145 bp; pSBP2_mcr4, 86,727 bp; and pSBP3, 56,972 bp). Plasmid pSBP2_mcr4 contains the mobile colistin resistance gene mcr-4.3, as well as the mercury resistance operon merRPAT. Plasmid pSBP1 carries genes encoding resistance against copper, zinc, chromium, and arsenic. Plasmid pSBP3 does not carry any antibiotic or heavy metal resistance genes. Analysis of the flanking region of mcr-4.3 suggests that a phage integrase may be involved in the mobilization of mcr-4.3 in Shewanella spp. Our results provide insights into the mobile mcr-4.3 present in Shewanella spp. and highlight the importance of the marine environment in the emergence and dissemination of clinically important resistance genes. IMPORTANCE We identified two new plasmids in Shewanella baltica isolated from wild Atlantic mackerel (Scomber scombrus) collected from the northern North Sea, one plasmid carrying the mcr-4.3 gene for colistin resistance and the operon merRPAT for mercury resistance and the other carrying multiple heavy metal resistance genes. The marine environment has been recognized as a source of new resistance genes that are found in human pathogens. Selection pressure from heavy metals is seen in the marine environment, especially associated with human activities, such as waste discharge, mining, and in aquaculture settings. This would help maintain and disseminate these plasmids in the environment. Our study provides insights into the mobilization of colistin resistance genes in Shewanella spp. and highlights the importance of the marine environment in the emergence and dissemination of clinically important antibiotic resistance genes.

The Resilience of Polar Collembola (Springtails) in a Changing Climate

Assessing the resilience of polar biota to climate change is essential for predicting the effects of changing environmental conditions for ecosystems. Collembola are abundant in terrestrial polar ecosystems and are integral to food-webs and soil nutrient cycling. Using available literature, we consider resistance (genetic diversity; behavioural avoidance and physiological tolerances; biotic interactions) and recovery potential for polar Collembola. Polar Collembola have high levels of genetic diversity, considerable capacity for behavioural avoidance, wide thermal tolerance ranges, physiological plasticity, generalist-opportunistic feeding habits and broad ecological niches. The biggest threats to the ongoing resistance of polar Collembola are increasing levels of dispersal (gene flow), increased mean and extreme temperatures, drought, changing biotic interactions, and the arrival and spread of invasive species. If resistance capacities are insufficient, numerous studies have highlighted that while some species can recover from disturbances quickly, complete community-level recovery is exceedingly slow. Species dwelling deeper in the soil profile may be less able to resist climate change and may not recover in ecologically realistic timescales given the current rate of climate change. Ultimately, diverse communities are more likely to have species or populations that are able to resist or recover from disturbances. While much of the Arctic has comparatively high levels of diversity and phenotypic plasticity; areas of Antarctica have extremely low levels of diversity and are potentially much more vulnerable to climate change.

Possibilities of Sustainable Development Including Improvement in Air Quality for the City of Murmansk-Examples of Best Practice from Scandinavia

The Russian city of Murmansk has about 300,000 inhabitants and is located inside the Arctic Circle in NE Scandinavia (Russia). It has one of the largest such concentrations of people in the Arctic. The city is a scientific, industrial, cultural, and transportation centre (an ice-free port in the so-called Northern Sea Route, connecting Europe with Asia). Currently, air pollution in the city is associated with outdated city heating technology, coal dust from the port and vehicular traffic, and so-called “small emissions”. The authors propose practical solutions based on known examples of Scandinavian cities with similar climatic conditions such as: the modernisation of heat energy acquisition; diversification of energy acquisition including renewable sources; thermal insulation of buildings; arrangement of urban greenery with dust-catching plants, and proposals for changing the habits within the population by promoting the use of public transport.