The COVID-19 pandemic posed a grave threat not only to Indigenous people\'s health and well-being, but also to Indigenous communities and societies. This applies also to the Indigenous peoples of the Arctic, where unintentional effects of public health actions to mitigate the spread of virus may have long-lasting effects on vulnerable communities. This study aim was to identify and describe Sámi perspectives on how the Sámi society in Sweden was specifically affected by the pandemic and associated public health actions during 2020-2021. A mixed-method qualitative case study approach was employed, including a media scoping review and stakeholder interviews. The media scoping review included 93 articles, published online or in print, from January 2020 to 1 September 2021, in Swedish or Norwegian, regarding the pandemic-related impacts on Sámi society in Sweden. The review informed a purposeful selection of 15 stakeholder qualitative interviews. Thematic analysis of the articles and interview transcripts generated five subthemes and two main themes: \"weathering the storm\" and \"stressing Sámi culture and society\". These reflect social dynamics which highlight stressors towards, and resilience within, the Sámi society during the pandemic. The results may be useful when evaluating and developing public health crisis response plans concerning or affecting the Sámi society in Sweden.

This paper outlines the methodological approaches to a multi-site Circumpolar case study exploring the impacts of COVID-19 on Indigenous and remote communities in 7 of 8 Arctic countries. Researchers involved with the project implemented a three-phase multi-site case study to assess the positive and negative societal outcomes associated with the COVID-19 pandemic in Arctic communities from 2020 to 2023. The goal of the multi-site case study was to identify community-driven models and evidence-based promising practices and recommendations that can help inform cohesive and coordinated public health responses and protocols related to future public health emergencies in the Arctic. Research sites included a minimum of 1 one community each from Canada (Nunavut,) United States of America (Alaska), Greenland, Iceland, Norway, Sweden, Finland. The approaches used for our multi-site case study provide a comprehensive, evidence-based account of the complex health challenges facing Arctic communities, offering insights into the effectiveness of interventions, while also privileging Indigenous local knowledge and voices. The mixed method multi-site case study approach enriched the understanding of unique regional health disparities and strengths during the pandemic. These methodological approaches serve as a valuable resource for policymakers, researchers, and healthcare professionals, informing future strategies and interventions.

The high Arctic is considered a pristine environment compared with many other regions in the northern hemisphere. It is becoming increasingly vulnerable to invasion by invasive alien species (IAS), however, as climate change leads to rapid loss of sea ice, changes in ocean temperature and salinity, and enhanced human activities. These changes are likely to increase the incidence of arrival and the potential for establishment of IAS in the region. To predict the impact of IAS, a group of experts in taxonomy, invasion biology and Arctic ecology carried out a horizon scanning exercise using the Svalbard archipelago as a case study, to identify the species that present the highest risk to biodiversity, human health and the economy within the next 10 years. A total of 114 species, currently absent from Svalbard, recorded once and/or identified only from environmental DNA samples, were initially identified as relevant for review. Seven species were found to present a high invasion risk and to potentially cause a significant negative impact on biodiversity and five species had the potential to have an economic impact on Svalbard. Decapod crabs, ascidians and barnacles dominated the list of highest risk marine IAS. Potential pathways of invasion were also researched, the most common were found associated with vessel traffic. We recommend (i) use of this approach as a key tool within the application of biosecurity measures in the wider high Arctic, (ii) the addition of this tool to early warning systems for strengthening existing surveillance measures; and (iii) that this approach is used to identify high-risk terrestrial and freshwater IAS to understand the overall threat facing the high Arctic. Without the application of biosecurity measures, including horizon scanning, there is a greater risk that marine IAS invasions will increase, leading to unforeseen changes in the environment and economy of the high Arctic.

The Barents Sea is a highly productive ecosystem within the Arctic Ocean. The overall biological productivity in this region relies heavily on the secondary mesozooplankton production (MZP). Previous research has primarily focused on mesozooplankton abundance (MZA) and biomass (MZB), lacking a comprehensive analysis of the environmental factors that influence MZP in the Arctic marine environment. The primary objective of this study was to examine the key factors responsible for the spatial variability in the community structure and MZP during the summer season. Data were collected from 52 stations in the central Barents Sea, specifically during post-bloom conditions in 2015. Through cluster analysis, two distinct groups of stations were identified, differing in terms of mesozooplankton taxa abundance. Copepods were found to dominate the mesozooplankton assemblages, comprising 89% of total MZA, 83% of MZB, and 68% of MZP. The biomass stocks in the study area varied from 8 to 102 mg dry mass (DM) m-3, with an average of 44 mg DM m-3. MZP rates ranged from 0.34 to 2.33 mg DM m-3 day-1, with an average of 1.16 mg DM m-3 day-1. The highest MZB and MZP values were observed at frontal zones that separated relatively warm and cold waters. Through redundancy analysis, it was determined that the primary environmental factors affected the distribution of mesozooplankton were longitude, latitude, and sampling depth. Temperature, salinity, and chlorophyll a concentration were found to have a less significant impact. These findings emphasize the importance of oceanographic conditions as the main predictors of mesozooplankton distribution during the summer season in the Arctic marine environment. This study highlights the essential role of environmental forcing in determining the productivity of Arctic marine zooplankton. Given the ongoing climatic changes, the results of this report can serve as a valuable tool for monitoring pelagic ecosystems in the Arctic.

Metal contamination has become an increasingly severe environmental issue due to intense anthropogenic activities in recent decades. Many studies have reported a rapidly increasing trend of heavy metal contents in sedimentary records. In this study, two lacustrine sediment cores (LDL and YL) far away from scientific research stations were collected in Ny-Ålesund and analyzed for the vertical distributions of 17 elemental concentrations (Cu, Zn, Pb, Co, Ni, Cr, Sr, Ba, Mn, P, Ti, K2O, Na2O, CaO, MgO, Fe2O3, Al2O3), CIA and TOC contents. The results indicated that only the proxies Pb, P, CaO, TOC, and CIA showed an increasing trend in the upper 7 cm section of the sediment cores, while most of the elements\' concentrations decreased towards the surface. The rapid increase of TOC contents is likely related to the climate warming over the past 200 years, which promotes the prosperity of vegetation and thus leads to more input of organic matter into the lakes. Moreover, a large number of seabirds live around the sampling position and the seabird guano contains high concentrations of P, which could be regarded as an important nutrient source for vegetation. Additionally, the rapid climate warming could accelerate the chemical weathering rates, and thus lead to increased CaO contents in the sediment profiles according to its geological background. Therefore, the concentrations of other elements are very likely diluted by the high contents of organic matter and CaO in the upper part of the sediment cores. It is noteworthy that the rapidly increasing trend of Pb contents are related to the gas-oil powered generators in Ny-Ålesund and long-range atmospheric transport from Europe. This study highlighted the nonnegligible influence of climate warming on the inorganic elemental geochemistry distributions in remote lakes.

Emergence of new technologies in remote sensing give scientists a new way to detect and monitor wildlife populations. In this study we assess the ability to detect and classify two emblematic Arctic cetaceans, the narwhal (Monodon monoceros) and beluga whale (Delphinapterus leucas), using very high-resolution (VHR) satellite imagery. We analyzed 12 VHR images acquired in August 2017 and 2019, collected by the WorldView-3 satellite, which has a maximum resolution of 0.31 m per pixel. The images covered Clearwater Fiord (138.8 km2), an area on eastern Baffin Island, Canada where belugas spend a large part of the summer, and Tremblay Sound (127.0 km2), a narrow water body located on the north shore of Baffin Island that is used by narwhals during the open water season. A total of 292 beluga whales and 109 narwhals were detected in the images. This study contributes to our understanding of Arctic cetacean distribution and highlights the capabilities of using satellite imagery to detect marine mammals.

Studies on the presence of atmospheric fungi in both Arctic and Antarctic polar areas are rare, and many of them were carried out briefly. Currently, when climate change is a fact, polar areas may be subject to various changes and fluctuations, negatively affecting sensitive polar ecosystems. The paper presents the results of tests on presence of fungi in the air over 30 years after the last investigations at the Svalbard Archipelago. A total of fifteen taxa of fungi were isolated in area of Longyearbyen, the majority of which were saprotrophic fungi of the genus Cladosporium that are associated with dead organic matter. Therefore, the presence of this taxon may be a good bioindicator of changes occurring in the Arctic environment, indirectly indicating the melting of glaciers and exposing increasingly larger areas inhabited by microorganisms, including fungi, which increase in number in the air. Additionally, the number of tourists visiting Longyearbyen is increasing, which may significantly affect the number and type of fungi in the air.

We present a case study on the impact of effluent from a wastewater lagoon-wetland system on phytoplankton and local primary production near a coastal Arctic community (Cambridge Bay) over spring to fall 2018. Results are also placed within an interannual and regional context for the surrounding Kitikmeot Sea. We find the shallow, relatively fresh Kitikmeot Sea is one of the most nutrient-deplete regions of the Arctic Ocean with NO3- + NO2- concentrations below the surface mixed layer rarely exceeding 2 μmol L-1 and a N:Si:P ratio of 1:6:1. The fjordal-type bathymetry of the main study site and a persistent pycnocline below the bay\'s exit sill led to slightly elevated N:Si:P of 3:11:1 through trapping of wastewater-sourced N at depth via sinking and remineralization of primary production. Total production in Cambridge Bay over the 3-month open water period was 12.1 g C m-2 with 70% of this production occurring during the 1-month discharge of wastewater into the system. Local primary production responded rapidly to high NO3- + NO2-, NH4+ and PON concentrations provided by wastewater effluent, comprising up to 20% of the production during the discharge period. Remaining production was mostly explained by the deep nutrient pool in the bay, which was only accessed towards the end of the discharge period as the diatom-dominated deep chlorophyll maximum settled below the pycnocline. Although not yet eutrophic, caution is raised at the rapid response of the marine system to wastewater release with a strong recommendation to develop a research and monitoring plan for the bay.

The present study was conducted to strengthen the knowledge on gut immune functions and health in Atlantic salmon under large scale, commercial conditions in the Arctic region of Norway. Two groups of fish were monitored, one fed a series of diets without functional ingredients (Ref) and the other diets with functional ingredients (Test). The nutritional composition of the two diet series varied in parallel according to the nutrient requirements of the fish during the observation time. The content of functional ingredients in the Test diets, i.e. nucleotides, yeast cell walls, a prebiotic and essential fatty acids, varied in accordance with a strategy developed by the feed company. The fish were observed at four sampling time points, the first (FW) in May 2016 two weeks before seawater transfer, the other three throughout the following seawater period until the fish reached a size of about 2 kg, i.e. in June, four weeks after seawater transfer (SW1); in November (SW2), and in April the following year (SW3). Gut health was assessed based on histopathological indicators of lipid malabsorption and gut inflammation, expression of gut immune, barrier and other health related genes, plasma biomarkers, somatic indices of intestinal sections, as well as biomarkers of digestive functions. Seawater transfer of the fish (SW1 compared to FW) caused a marked lowering of expression of genes related to immune and barrier functions in the distal intestine, i.e. cytokines (il1β, il10, tgfβ, ifnγ), T-cell markers (cd3γδ), myd88 and tight junction proteins (zo-1, claudin-15, claudin-25b), indicating suppressed immune and barrier functions. At SW2 and SW3, most of the immune biomarkers showed values similar to those observed at FW. The development of plasma cholesterol and triglyceride levels showed similar picture, with markedly lower levels after seawater transfer. Lipid malabsorption was observed in particular in fish from SW1 and SW2, as indicated by hyper-vacuolation of the pyloric caeca enterocytes with concurrently increased expression levels of plin2. Regarding effects of functional ingredients, significantly lower condition factor and plasma triglyceride level were observed for Test-fed fish at SW2, indicating a metabolic cost of use of a mixture of nucleotides, yeast cell walls and essential fatty acids. No clear effects of functional ingredients on expression of gut immune genes and other health indexes were observed through the observation period. The great, temporary lowering of expression of gut immune and barrier genes at SW1 is suggested to be an important factor underlying the increased vulnerability of the fish at this time point. Our findings regarding supplementation with functional ingredients raise questions whether some of these ingredients overall are beneficial or might come with a metabolic cost. Our results highlight the need for a better understanding of the cause and consequences of the suppression of gut immune functions of farmed Atlantic salmon just after seawater transfer, and the use of functional ingredients under commercial conditions.

Arctic and subarctic ecosystems are experiencing substantial changes in hydrology, vegetation, permafrost conditions, and carbon cycling, in response to climatic change and other anthropogenic drivers, and these changes are likely to continue over this century. The total magnitude of these changes results from multiple interactions among these drivers. Field measurements can address the overall responses to different changing drivers, but are less capable of quantifying the interactions among them. Currently, a comprehensive assessment of the drivers of ecosystem changes, and the magnitude of their direct and indirect impacts on subarctic ecosystems, is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years, and is one of the most studied sites in the Arctic. In this study, we summarize and rank the drivers of ecosystem change in the Torneträsk area, and propose research priorities identified, by expert assessment, to improve predictions of ecosystem changes. The research priorities identified include understanding impacts on ecosystems brought on by altered frequency and intensity of winter warming events, evapotranspiration rates, rainfall, duration of snow cover and lake-ice, changed soil moisture, and droughts. This case study can help us understand the ongoing ecosystem changes occurring in the Torneträsk area, and contribute to improve predictions of future ecosystem changes at a larger scale. This understanding will provide the basis for the future mitigation and adaptation plans needed in a changing climate.