The Canadian Arctic is warming faster than the global average, posing significant challenges for Inuit whose livelihoods are closely linked to the environment. Climate change exacerbates food insecurity in Inuit communities by impacting the availability, access, quality, utilization and long-term stability of country foods. Inuit observations indicate that changes in temperature, precipitation, wildlife, weather, and ice conditions impact harvesting opportunities, travel safety, and country food consumption. Focusing on the Inuvialuit Settlement Region (ISR), this study links documented climate change impacts on country food security with projected environmental conditions to assess potential future risks. An integrative synthesis of exposure-sensitivities reveals that environmental changes are interconnected, multidimensional, and compounded across the Inuit food system. Findings indicate that food access is expected to be the most affected food security dimension over the next 20 to 30 years, while food availability is also likely to decline as key species face ecological stress and shifting harvesting pressure. While Inuit communities have long adapted through sharing networks, opportunistic harvesting, and increased reliance on store-bought foods, shorter-term coping mechanisms may not fully address future risks. This retrospective study provides a regionally grounded assessment of underlying causes affecting long-term food security in the ISR to inform forward-looking strategies.
Climate warming and increasing fire frequency are reshaping Arctic vegetation communities through changes in disturbance and nutrient availability, yet whether fire and nutrient enrichment drive similar or distinct pathways of vegetation reorganization remains unclear. We assessed rates and trajectories of vegetation change using a 10-year, two-factor nitrogen and phosphorus fertilization experiment (N+, P+, NP+) in burned and unburned Alaskan treeless moist acidic tussock tundra. Fertilization at the burned site began after canopy closure, allowing assessment of how fire legacy effects from approximately a decade earlier influenced tundra responses. Nitrogen and phosphorus co-limitation strongly regulated vegetation responses, with NP+ producing the largest increases in canopy leaf area, surface greenness, and compositional change. Fire and NP+ drove similar directional shifts in vegetation composition, characterized by declines in mosses and lichens and increases in forbs and deciduous shrubs. These changes were associated with reduced community resistance, increased divergence from unfertilized controls, and higher leaf area index and surface greenness. Fire accelerated community reorganization, while NP+ promoted persistent movement toward novel community states in both burned and unburned tundra. Limited fire × fertilization interactions suggest largely additive effects, with implications for shrubification, ecosystem function, and fire–climate feedbacks under continued warming.
Winter feeding of reindeer (Rangifer tarandus tarandus) has become increasingly common in reindeer husbandry to compensate for reduced natural grazing caused by competing land use and climate change. While feeding improves reindeer body condition, survival, and calving success in the short term, its delayed effects on reindeer behavior and performance remain unclear. This study explores herders’ perceptions of early and delayed effects of winter feeding on reindeer through 19 semi-structured interviews with reindeer herders in Sweden and Finland. Reported effects varied among herders, as did perceptions of whether an effect was positive or negative. Physical effects included changes in survival, body mass, body condition, and health, predominantly observed during feeding and the following summer. Behavioral effects included increased tameness, habituation to feeding, altered foraging behavior, disrupted spring migration, and reduced maternal care, with most persisting into the following autumn and winter. Delayed effects reportedly became more pronounced after regular feeding over several years, especially when reindeer were fed in enclosures. Even when the effects on reindeer were considered negative, many herders emphasized that they felt they had no option other than to feed, and that it was difficult to stop feeding once it had become a regular practice.
Cloud-to-ground (CG) lightning frequency is projected to increase under future warming scenarios in Canada’s boreal forest. In this study, we examine historical (1998–2023) CG lightning flash trends along the interface of boreal forest and Arctic tundra (encompassing northern Manitoba and the southern Kivalliq Region of Nunavut). Using the Canadian Lightning Detection Network, we assess whether projected trends in lightning flash density are already discernable, how other lightning characteristics (such as polarity and intensity of current) are changing, and, using the ERA5 atmospheric reanalysis, whether changing lightning characteristics are explainable by associated thunderstorm environments. We find that positively charged CG lightning (+CG) is increasing throughout the study area, although negatively charged CG lightning (−CG) remains the dominant lightning polarity. Trends in other lightning characteristics demonstrate regional variations and suggest a strong role for internal variability. Southern Kivalliq stands out as the region exhibiting the greatest relative increases in lightning frequency and intensity. Northern Manitoba exhibits an overall decline in lightning frequency (due to fewer −CG flashes), although the −CG current strength is increasing. The shift toward relatively more +CG events aligns with changes in the thunderstorm environment in southern Kivalliq. Elsewhere, driving mechanism trends are either weak or counteract each other.
The extent to which lakes mix modulates dissolved oxygen and biogeochemical conditions within the water column. The mixing dynamics of Arctic delta lakes have not been investigated in detail and have been treated as cool, shallow systems influenced by routine flooding. Past biogeochemical studies have presumed these lakes mix and release winter-derived gases at ice-off. Here we assess stratification and extent of mixing over a full year in a 5-m deep, floodplain lake located in the Mackenzie Delta (NT, Canada). Moored arrays and a meteorology station enabled calculation of physical parameters such as density, Lake number, buoyancy frequency, and heat budgets. The lake received only minor river flooding and never completely mixed during the year. A chemocline prevented turnover at ice-off. This was followed by strong thermal and chemical stratification when ice-free, resisting wind-induced mixing across the thermocline even through fall. A 3-layer structure developed with an upper mixed layer, metalimnion, and monimolimnion. Each layer had distinct dissolved oxygen levels, with the highest concentrations in the metalimnion and hypoxia in the monimolimnion, where CH4 accumulated. These results, in combination with prior studies’ measurements of CH4 in bottom-waters, implies this lake is in a state of continuous multi-year stratification.
The Arctic tundra is warming faster than any other biome, and its biodiversity, ecosystem functions, and Indigenous land use are increasingly shaped by interacting climate- and human-driven stressors. Conservation planning must therefore move beyond static protected-area targets toward approaches that explicitly account for future change. Here, we synthesize the major stressors that will shape tundra futures (woody plant expansion, permafrost thaw and associated disturbance dynamics, accelerating industrial development and infrastructure), and explain why their differing rates and interactions create a moving target for protection. We then identify key data and scenario gaps that currently limit circumpolar prioritization, including insufficient understanding of biodiversity responses to core stressors, uneven monitoring capacity to detect change and locate refugia, and limited integration of biodiversity change with ecosystem functions and culturally important areas. Building on this, we outline the concept of a step-by-step, scenario-based decision-support workflow for dynamic systematic conservation planning. Finally, we describe co-design and governance pathways for implementation and iteration with Indigenous peoples and local communities, stakeholders, and policymakers to reduce conflicts, increase legitimacy, and enable adaptive updates as conditions change. Together, these steps provide an actionable foundation for proactive tundra conservation under rapid Arctic change.
This study assesses shoreline change dynamics in the Tuktoyaktuk Peninsula, Beaufort Sea (Canada), using aerial photography-derived orthomosaics (1950, 1985) and very high-resolution Pléiades satellite (2020) imagery. We (1) characterised backshore and foreshore morphologies, (2) analysed spatiotemporal shoreline change rates, and (3) identified the morphology influence on shoreline evolution. The average shoreline change rate was -0.77 m/yr , with a 31% increase since 1985, affecting 57% of the area. Shoreline retreat affected at least 83% of the shoreline in each sector, with the highest rates in the central sectors of the peninsula. Coastal morphology was the main factor influencing spatial variability and the dominant shoreline retreat processes. Tundra flats showed the highest retreat rates in backshore and foreshore, displaying the highest rates and 38% of land loss, despite covering 29% of the peninsula. These results challenge erosion-centric models of Arctic coastal change, highlighting submergence as a dominant process in low-lying coasts. The erosion-submergence distinction is critical for improving predictive models and adaptation strategies in vulnerable communities like Tuktoyaktuk. Future research must integrate subsidence measurements, sea-level rise, inundation impacts and coastal morphology to address gaps in shoreline change models and impacts on Arctic coastal systems.
“Doom and gloom” has become a dominant narrative about the impacts of climate change on the Arctic and its unique cold-adapted biodiversity. However, recent work highlights that such narratives can prevent us from being proactive and taking the steps needed to create the best possible future. Visioning of “desirable” futures can help overcome negative mindsets and inspire transformative action. We co-created visions of desirable futures for Arctic biodiversity during a workshop including representatives from academia, Indigenous Peoples, business and policymaking. Appreciating our diverse perspectives, we identified common themes in our visions: governance, biodiversity-climate interactions, co-management of ecosystems, economy and infrastructure, and food security. Using backcasting, we determined high-level actions that would enable the positive outcomes shared by our visions: boosting education, rethinking Arctic biodiversity governance, elevating voices of Indigenous Peoples and voices of local communities, developing scalable monitoring systems, and evaluating impacts of policies and economic activities. Many of us reported a positive shift in attitude and feeling empowered after the workshop. Co-creating visions with a diverse group was perceived as particularly valuable. We report the workshop method and, building on our experience, encourage people from all backgrounds to envision and co-create the best possible future for Arctic biodiversity.
Greenland (Kalaallit Nunaat) is undergoing significant environmental transformations due to the confluence of climate change and societal development. This paper reviews existing research on the human dimensions of climate change in Greenland across various sectors, examines how adaptation is occurring and the associated barriers and opportunities, assesses climate governance and how decision-making has impacted adaptation, and identifies critical research gaps. Climate changes are having the largest impacts on Greenlanders who practice traditional lifestyles and live in small settlements but are also creating new economic opportunities. More research is needed regarding how to channel these opportunities to benefit Greenlanders, and there are gaps in understanding how non-hunters, women, and children, are being affected by climate change. Climate adaptation in Greenland is an evolving process. Most documented adaptation strategies are community-led and autonomous and there is a need for more proactive and planned adaptation. Additional work is needed to evaluate implemented adaptations, and on potential climate impacts under different warming levels and transformation trajectories. Reported adaptation barriers include historically limited involvement of Kalaallit communities in government-led adaptation planning, insufficient resources, restrictive international and governmental regulations, and limited climate science education.
The Kuujjuaq Estuary (Nunavik, Canada) faces significant ecological and logistical challenges due to its unique geomorphology, limited infrastructure, and increasing maritime activity. This study introduces tailored coastal sensitivity and vulnerability indices to improve preparedness in the event of a maritime incident, with the goal of better protecting local residents and their use of coastal resources and ecosystems. By integrating Inuit Knowledge (IK) with scientific datasets, the research addresses critical local environmental concerns and supports informed decision-making for emergency response planning. Three sensitivity indices and one vulnerability index were developed -Social (SSI), Morphological (MVI) and two Biologicals (BSI) -through community engagement, cartographic analysis, and the integration of geomorphological and socioecological data. Findings reveal that 50% of the estuary is particularly vulnerable to maritime incidents mainly due to many harvesting areas together with marshes, emphasizing the need for targeted mitigation measures. This work lays the groundwork for resilient and adaptive coastal management strategies in the Kuujjuaq Estuary, fostering enhanced preparedness and response capacity through a collaborative and culturally grounded framework.
Native pink salmon have shown low occurrence of vertebral deformities and large inter-population variation in number of vertebrae in the Pacific Ocean. Invasive pink salmon have, however, not been assessed for these endpoints in the North Atlantic and Arctic oceans. The present study assessed number of vertebrae and vertebral deformities (radiology) in the 2020, 2022 and 2024 year-classes of invasive pink salmon captured in Norway. The prevalence’s of vertebral deformities (mean 29%) were higher than earlier reported in native pink salmon. The observed deformities were worse in the 2024 year-class where two adult fish with severe deformities were observed in Arctic waters. More specifically, one fish with whole body kypho-lordo-kyphosis captured in Finnmark, and one fish with complete ural region vertebral fusion and folding of the tail fin captured in Troms. Finally, a significantly lower number of total vertebrae were observed in the 2024 year-class (mean 70.2) compared to the 2020 and 2022 (both mean 70.8) year-classes. The change in number of vertebrae between year-classes is discussed in relation to early life thermal regime and genotype. The currently observed 3.5% prevalence of severely deformed adult pink salmon in the Arctic may be a warning sign of reduced ecosystem health. The present findings argue for including vertebral deformities and meristics in the surveillance of invasive pink salmon in Norway.
Foxe Basin is a shallow inland sea in the Canadian Arctic that has strong tidal dynamics and is covered by a notoriously deformed and dirty sea ice cover for 9 months a year. Observations are limited, but the proposed development of year-round shipping to Steensby Inlet in northern Foxe Basin makes it imperative to characterize the ice pack. Using a new processing scheme to improve standard estimates of ice thickness from ICESat-2 we provide the first detailed examination of the regional sea-ice dynamics. Ice thickness varies considerably across the Basin, from thin ice in the polynyas of western Foxe Basin to ice thicker than 6 m in eastern Foxe Basin. The prevailing north-northwesterly winds drive much of this asymmetry, while tidal dynamics amplify deformation throughout Foxe Basin, particularly in the east where tidal ranges reach 5 m during winter. Tides promote the formation of thick, sediment-laden ice in tidal flaw leads, which form in shallow coastal waters, and tidal-bathymetry polynyas. These areas of persistent low sea ice concentrations within the ice pack are suggested to be the result of divergent ice drift caused by shallow bathymetry. Ice thickness along the proposed shipping route is interpreted with recommendations for future observations.
A 25-year record from Toolik Lake, a tundra lake in Northern Alaska, shows a strikingly consistent, recurring seasonal pattern of bacterial community composition. Diversity in the epilimnion and hypolimnion tracks thermal stratification, underscoring the importance of physical drivers in shaping short-term assemblages. Over winter, the hypolimnion serves as a reservoir of diversity, producing similar pre-thaw spring communities annually. Since 2000, summer bacterial communities showed greater seasonal than interannual variability, although several taxa showed long-term directional shifts: Alphaproteobacteria declined, while orders within Bacteroidia, Actinobacteria, and Gammaproteobacteria, and members of the unicellular picocyanobacterial genus Cyanobium increased. Over the same period, lake conductivity increased, while temperature, stratification, and bacterial production showed no significant trends. The persistent seasonal reassembly of microbial communities over 25 years suggests that the absence of long-term directional change in the lake’s physical regime, despite interannual variability, maintains these recurring patterns even as other environmental conditions change. These results show how strong seasonal drivers of microbial communities can maintain and support persistent community composition across decades. However, the rise in cyanobacteria reflects global trends and underscores the value of long-term microbial records in detecting early ecological change before it becomes apparent in routine aquatic monitoring.
High nitrous oxide (N 2 O) emissions from bare peat surfaces in permafrost peatlands are mainly produced by denitrification but depend on nitrate (NO 3 − ) supply through nitrification. Here, we investigated the effect of experimental warming on ammonia oxidizers, who catalyze the rate limiting step of nitrification, in bare peat surfaces. We determined the abundance and community composition of amoA genes in warmed and control plots, and combined these results with gross nitrification rates and previously reported data on mineral nitrogen (N) pools, soil N 2 O concentrations, and surface emissions. Ammonia oxidizer communities comprised only a few closely related amplicon sequence variants (ASV) of ammonia-oxidizing archaea. Contrary to our expectations, warming did not cause significant changes in the archaeal amoA abundance but shifted their community composition: a single ASV of the Zeta (ζ) clade of Nitrososphaera became highly dominant in subsurface peat, where a tendency towards higher gross nitrification rates, although not significant, was observed . High NO 3 − concentrations and gross nitrification rates indicated that denitrification was not limited by NO 3 − availability. Thus, increased N 2 O emissions with warming were not caused by enhanced nitrification. However, the sensitivity of the nitrifier community to the mild warming treatment suggests that compositional shifts are expected in Arctic soils under a future warmer climate, which may have implications for N turnover.
The high northern latitudes are warming rapidly, reducing sea ice coverage and altering salinity regimes, with widespread ecosystem-level consequences. Although horizontal range shifts of marine animals under climate change are well documented, long-term changes in vertical habitat use by marine predators remain poorly understood. We analyzed a three-decade biologging dataset (1992–2019) from 45 hooded seals (Cystophora cristata) breeding in the Gulf of St. Lawrence to investigate how this population has altered its diving behaviour in response to climate change. Using multinomial generalized additive mixed models, we quantified dive duration and depth across sex, functional oceanographic domains, decade, and season. As males and females differ in physiology, and partition the water column during foraging, we assessed whether climate-driven changes in vertical habitat structure would differentially affect the diving behaviour between sexes. Sexual dimorphism persisted, with females making shorter and shallower dives more frequently than males. However, both sexes experienced marked shifts in dive duration, from predominantly 5–15 min dives in the 1990s to 15–25 min dives in the 2000s and 2010s. These changes were spatially structured, reflecting basin-scale thermohaline reorganization, and temporally coordinated with migration. Shallow dives dominated early and late migration, whereas deeper, longer dives peaked mid-migration. Our results demonstrate behavioural plasticity in response to changing vertical habitat conditions.
Small mammal cycles have been studied for 100 years, but the field still lacks consensus on their underlaying causes. Time-series analyses are a key approach to the study of cycles, with monitoring methods arguably limiting the understanding that is possible to gain. During the last decade, camera traps have been tested and implemented as a method for long-term monitoring, with the potential for new avenues. Here, we identify key aspects of camera trapping for future research; i) the possibility to provide data at a temporal scale that matches the fast life-histories of small mammals, ii) the indiscriminatory monitoring of the entire small mammal community, iii) the possibility to match population dynamics data with simultaneously collected data on climatic events, and iv) the potential for spatially spread monitoring designs enabling research on large-scale spatial aspects of population dynamics. We further highlight necessary developments, namely i) developing automatic image annotation models with species-level detection, ii) advancing the methodology of calculating abundance estimates from unidentified individuals, and iii) finding the adequate analytical tools to analyse high-resolution time-series. In summary, camera trapping methodology has the potential to expand the limits of achievable knowledge, but focused, collaborative research on key methodological challenges is still needed.
The timing and mechanisms of permafrost thaw and erosion prior to human influence provide essential context for permafrost carbon mobility under arctic warming. Because arctic lake sediments archive erosional products from permafrost that age significantly on the landscape before remobilizing into the lake, the range of radiocarbon ages (age-offset) present in the lake sediment can indicate the relative contribution of ancient permafrost-derived organic carbon (OC) through time. We use age-offsets from Lake E5, northeastern Alaska, to reveal changes in the contribution of aged permafrost-derived OC deposited in the lake sediment over the last 45 thousand years. To do this, we combine the 14C dating of paired bulk sediment and plant macrofossils from the same stratigraphic layer of lake sediment and ramped pyrolysis-oxidation (RPO) 14C analysis. Lake E5 revealed small age-offsets (1580 years) during the post-glacial period, large age-offsets (27 200 years) during the Last Glacial Maximum, and moderate age-offsets (15 100 years) during the MIS 3 interstadial. These temporal patterns broadly align with our recently published findings from Burial Lake, northwestern Alaska, highlighting the importance of vegetation, soil development, moisture availability, and erosional mechanisms in controlling carbon mobility in Arctic Alaska while key differences emphasize the individuality of lake basins.
