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Climate-driven sea ice loss has led to changes in the timing of key biological events in the Arctic, however, the consequences and rate of these changes remain largely unknown. Polar bears (Ursus maritimus) undergo seasonal changes in energy stores in relation to foraging opportunities and habitat conditions. Declining sea ice has been linked to reduced body condition in some subpopulations, however, the specific timing and duration of the feeding period when bears acquire most of their energy stores and its relationship to the timing of ice break-up is poorly understood. We used community-based sampling to investigate seasonality in body condition (energy stores) of polar bears in Nunavut, Canada, and examined the influence of sea ice variables. We used adipose tissue lipid content as an index of body condition for 1,206 polar bears harvested from 2010-2017 across five subpopulations with varying seasonal ice conditions: Baffin Bay (October-August), Davis Strait and Foxe Basin (year-round), Gulf of Boothia and Lancaster Sound (August-May). Similar seasonal patterns were found in body condition across subpopulations with bears at their nadir of condition in the spring, followed by fat accumulation past break-up date and subsequent peak body condition in autumn, indicating that bears are actively foraging in late spring and early summer. Late season feeding implies that even minor advances in the timing of break-up may have detrimental effects on foraging opportunities, body condition, and subsequent reproduction and survival. The magnitude of seasonal changes in body condition varied across the study area, presumably driven by local environmental conditions. Our results demonstrate how community-based monitoring of polar bears can reveal population-level responses to climate warming in advance of detectable demographic change. Our data on the seasonal timing of polar bear foraging and energy storage should inform predictive models of the effects of climate-mediated sea ice loss., (© 2019 John Wiley & Sons Ltd.)

The present paper seeks to lay bare how the grim realities of settler colonialism and petro-capitalism have a tolling effect on the indigenous ways of life. The present era, termed the 'Anthropocene' or 'Capitalocene,' as it is the capitalist concern of some of the privileged anthropos that inflict socio-economic and ecological injustices on earth, heralds the birth of cautionary literature that deconstructs anthropocentric fixation to purge the earth off the catastrophic impacts of rapacious human activities. In order to examine how capitalism and its resultant climate emergency have spurred environmental activists and authors to reflect upon this theme, the paper undertakes a close textual analysis of The Breathing Hole (2020) by Colleen Murphy (b. 1954), a contemporary Quebecois playwright. By employing indigenous ecocriticism and non-human turn in literary studies, the study examines how the playwright jettisons the standardised category of the Anthropos by prioritising the non-human character, Angu'ruaq, an anthropomorphised polar bear. Attempts have been made to highlight how the capitalist motive of the neo-colonial agents leaves a breach in the fabric of the succouring connection between the indigenous Inuit existence and the non-human beings in the Nunavut territory of the Canadian Arctic. The findings of the paper demonstrate how the playwright approaches contemporary eco-crisis using indigenous ecodrama. [ABSTRACT FROM AUTHOR]

Climate change has increasing visible effects on the environment, particularly in the Arctic, where the sea-ice melted faster in 2020 than any time before. It directly threatens the Inuit people's survival, whose livelihood is mainly based on traditional modes of subsistence (hunting, fishing and gathering). In light of the environmental crisis, this paper carries out a critical analysis of the Nunavut (Canada) legal framework, granting Inuit specific rights regarding their traditional way of life. While recognizing that this framework implements international human rights legal standards, we argue that the human right lens presents limitations in addressing climate change impacts on Inuit livelihood. By acknowledging the developments following the adoption of the United Nations Declarations on the Rights of Indigenous Peoples and on the Rights of Peasants and Other Peoples Living in Rural Areas, leading to the recognition of some collective rights to communities and people living of the land, we address the gaps of human rights –which are mainly individual –to reflect the importance of recognizing collective rights in the adaptation to the global climate change challenge. Indeed, the paper argues for the necessity to recognize the community level in the climate international governance scene. [ABSTRACT FROM AUTHOR]

This paper engages narratives from Tess Lea's (2020) book 'Wild Policy' for how they help consider the messy or 'wild' nature of global policy interventions on sustainability, including in its latest formation as the UN Sustainable Development Goals (SDGs). We do so alongside data from research on education in the territory of Nunavut, as well as informed by our experiences as settler and Cree university researchers concerned with place and land-informed education policy. Engaging with a methodological framing of policy ecology, the article considers both policy artifacts and 'ambiences' or materialities, and their interrelations. We examine how a Saskatchewan university's draft SDG plan manifests aspects of pre-fabricated globally mobile 'wild policy', including in its gaps in land-informed Indigenous engagement. Instead, we suggest how more systemic and decolonizing approaches to land-informed education policy, as in development in Inuit-based higher education in Nunavut, can inform both future policy decision-making and policy research. [ABSTRACT FROM AUTHOR]

The paper deals with numerical computations of hydraulic variations and groundwater flow changes in continuous permafrost due to climate change and open-pit mining in the cold regions of Northern Canada. The work is a case study in connection with the proposed Kiggavik project in Nunavut, Canada. A major challenge in simulating fluid flow through partially frozen porous media is how to define the transient hydraulic conductivity as a function of temperature. An indirect approach based on the similarity between soil freezing and soil–water characteristic curves for unsaturated soils is implemented to define the relation between unfrozen water content and cryogenic suction which is linked to temperature by the Clausius–Clapeyron equation. Richard's equation is then used to model fluid flow in partially frozen ground conditions. Finite element numerical modelling results of a worst-case climate change scenario indicate that although the permafrost could disappear completely in about 750 years with an increase in 7 ∘ C in the mean annual ground surface temperature during the next 100 years, the groundwater level around tailings facility would be approximately 35 m below ground surface. Hence, tailings pore water would not likely to migrate upwards to reach the ground surface even after the permafrost is completely disappeared. These conclusions are certainly within uncertainties and limitations of the analysis. [ABSTRACT FROM AUTHOR]

Permafrost in northern Canada is susceptible to degradation due to rapid climate change, with hazard mapping promoted as an important activity to guide sustainable community adaptation and planning. This paper presents a framework for evaluating permafrost mapping exercises designed to inform climate change adaptation actions. We apply the framework using a case study of the Incorporating Climate Change into Land Development—Terrain Analysis project (ICCiLD). ICCiLD is a hazard mapping project utilizing interferometric synthetic aperture radar to monitor ground disturbance and categorize land development suitability in seven communities in the territory of Nunavut, Canada. We looked at one of the communities, Arviat, as our case study. We examined technical data and drew upon semi-structured interviews (n = 19) with map creators and users. We found ICCiLD added new and relevant information for community planning, increased awareness of the risks posed by permafrost thaw and built stakeholder relations. Strong coordination and high public consciousness of local climate impacts emerged as key factors underpinning project success. Nevertheless, in the case of Arviat, the effectiveness of the hazard maps in influencing land-use planning was constrained by communication challenges between project creators and end-users. These challenges included limited community access to the data and uncertainty surrounding how to operationalize the map suitability classifications. Broader climate change adaptation challenges included the presence of other more immediate community planning priorities and a limited ability to incorporate Indigenous ways of knowing into a technical mapping project. The lessons from this evaluation provide insight for the development of mapping-based adaptations across Arctic regions. [ABSTRACT FROM AUTHOR]

There is limited knowledge on institutional factors constraining and enabling climate change adaptation in Arctic regions, or the overall readiness of governing bodies and communities to develop, implement, and promote adaptation. This paper examines the preparedness of different levels of government to adapt in the Canadian Arctic territory of Nunavut, drawing upon semi-structured interviews with government personnel and organizations involved in adaptation. In the Government of Nunavut, there have been notable developments around adaptation planning and examples of adaptation champions, but readiness for adaptation is challenged by a number of factors including the existence of pressing socio-economic problems, and institutional and governmental barriers. Federally, there is evidence of high-level leadership on adaptation, the creation of adaptation programs, and allocation of funds for adaptation, although the focus has been mostly on researching adaptation options as opposed to supporting actual actions or policy change. The 2016 Pan-Canadian Framework on Clean Growth and Climate Change, and increasing emphasis on climate change federally and in the Government of Nunavut, offer opportunities for advancing adaptation, but concrete steps are needed to ensure readiness is enhanced. [ABSTRACT FROM AUTHOR]

The Canadian Arctic has been undergoing profound and damaging environmental changes in recent decades at an ever-accelerating rate. In addition to climate change, a wide variety of other factors are dramatically affecting water quality, biodiversity, land stability and ice reliability. These changes have a particularly negatively impact upon population health, local transportation, traditional knowledge, cultural identity, food supply and lifestyle of the Inuit. This paper examines the threats being imposed upon the Inuit in the Canadian Arctic and their capacity to respond directly through exercising opportunities available through recent land claim settlements and northern governments in which they play a dominant role. The paper then considers the limited capacity of the federal government to deal with northern environmental issues and the potential available through enforcing international environmental agreements and human rights. [ABSTRACT FROM AUTHOR]

This paper develops a conceptual model to examine the vulnerability of Inuit food systems to food insecurity as a consequence of climate change. The model illustrates that food system vulnerability is determined by the exposure and sensitivity of the food system to climate-related risks and its adaptive capacity to deal with those risks. The model is empirically applied using a case study from Igloolik, Nunavut. Specifically, the paper focuses on how extreme climate-related conditions in 2006 interacted with the food system to affect food security, using 2006 as a lens to identify and characterize some of the processes and conditions shaping vulnerability, and establishing a baseline for identifying and characterizing processes that are likely to shape future vulnerability. There is a high level of adaptive capacity among Igloolik Inuit, with food sharing mechanisms, hunting flexibility, and store-food access moderating the impact of climatic-risks on food security. However, high fuel and commodity prices, the increasing economic burden of adapting to back-to-back years with unfavorable climatic conditions, underlying community vulnerabilities, and the nature to the climate extremes in 2006, overwhelmed the adaptive capacity of many community members. Those dependent on traditional foods and having limited access to financial resources were particularly vulnerable. [ABSTRACT FROM AUTHOR]

The observations of community members and instrumental records indicate changes in sea ice around the Inuit community of Igloolik, in the Canadian territory of Nunavut. This paper characterizes local vulnerability to these changes, identifying who is vulnerable, to what stresses, and why, focusing on local and regional use of sea ice for the harvesting of renewable resources and travel. This analysis is coupled with instrumental and sea ice data to evaluate changing temperature/wind/sea ice trends over time, to complement local observations. We demonstrate the relationships between changing sea ice conditions/dynamics and harvesting activities (i.e. dangers and accessibility), with specific emphasis on ringed seal and walrus seasonal hunting, to illustrate current sea ice exposures that hunters are facing. Community members are adapting to such changes, as they have done for generations. However, current adaptive capacity is both enabled, and constrained, by social, cultural, and economic factors that manifest within the modern northern Hamlet. Enabling factors include the ability of hunters to manage or share the risks associated with sea ice travel, as well as through their flexibility in resource use, as facilitated by sophisticated local knowledge and land/navigational skills. Constraining factors include the erosion of land-based knowledge and skills, altered sharing networks, as well as financial and temporal limitations on travel/harvesting. The differential ability of community members to balance enabling and constraining factors, in relation to current exposures, comprises their level of vulnerability to sea ice change. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper examines Neo-Inuit (ca. AD 1250 to present) responses to the decreased temperatures of the Little Ice Age (LIA) climate change episode (ca. AD 1300–1900) in the Foxe Basin region of central Nunavut, Arctic Canada. Cooler temperatures (and increased sea ice) would be expected to have reduced both bowhead whale (Balaena mysticetus) and Atlantic walrus (Odobenus rosmarus rosmarus) habitats, forcing Neo-Inuit to refocus their hunting activities on landfast-ice-dwelling small seals (e.g., Pusa hispida) during winter months. However, an analysis of faunal remains from Foxe Basin's largest-known Neo-Inuit (Thule, historic and modern Inuit) archaeological site, Pingiqqalik (NgHd-1), reveals a long-term subsistence economy based largely on multi-seasonal walrus hunting. Two interrelated factors may explain these results: (1) a system of recurring polynyas provided a degree of ecological stability for local walrus populations, and (2) the development of a distinctive walrus caching regime—a form of which continues among the region's contemporary Inuit—allowed residents to adeptly exploit an ecological niche, thereby ensuring food security. Together, these factors likely insulated northern Foxe Basin Neo-Inuit from the worst effects of the LIA. [ABSTRACT FROM AUTHOR]

The paper is concerned with thermal disturbances in continuous permafrost due to open pit mining and tailings impoundment in the cold regions of Northern Canada. Numerical simulations were conducted to investigate issues of thermal regime changes and permafrost degradation in both the short term and the long term in connection with the proposed Kiggavik project in Nunavut, Canada. The results of numerical simulations indicate that no open talik would form below the East Zone and Center Zone pits during the estimated mining and milling operation period of 14 years, although a thin thawed zone would develop surrounding the open pits. For the Main Zone pit where the excavation would break through permafrost, the open talik remains following an extended operation period of 25 years with a 5 to 30 m thawed zone along the pit side walls. In the long term, with a plausible climate change scenario of 5 °C increase in the mean annual ground surface temperature during the next 100 years, the permafrost surrounding the in-pit tailings management facilities (TMFs) would reduce greatly in about 500 years. However, an approximately 40 m thick permafrost layer would remain on the top of the TMFs, which is impervious and would prevent any tailings pore water from migrating upward to reach the ground surface. [ABSTRACT FROM AUTHOR]

As climate change impacts are felt around the globe, people are increasingly exposed to changes in weather patterns, wildlife and vegetation, and water and food quality, access and availability in their local regions. These changes can impact human health and well-being in a variety of ways: increased risk of foodborne and waterborne diseases; increased frequency and distribution of vector-borne disease; increased mortality and injury due to extreme weather events and heat waves; increased respiratory and cardiovascular disease due to changes in air quality and increased allergens in the air; and increased susceptibility to mental and emotional health challenges. While climate change is a global phenomenon, the impacts are experienced most acutely in place; as such, a sense of place, place-attachment, and place-based identities are important indicators for climate-related health and adaptation. Representing one of the first qualitative case studies to examine the connections among climate change, a changing sense of place, and health in an Inuit context, this research draws data from a multi-year community-driven case study situated in the Inuit community of Rigolet, Nunatsiavut, Canada. Data informing this paper were drawn from the narrative analysis of 72 in-depth interviews conducted from November 2009 to October 2010, as well as from the descriptive analysis of 112 questionnaires from a survey in October 2010 (95% response rate). The findings illustrated that climate change is negatively affecting feelings of place attachment by disrupting hunting, fishing, foraging, trapping, and traveling, and changing local landscapes-changes which subsequently impact physical, mental, and emotional health and well-being. These results also highlight the need to develop context-specific climate-health planning and adaptation programs, and call for an understanding of place-attachment as a vital indicator of health and well-being and for climate change to be framed as an important determinant of health., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

As the climate warms, stressors are developing that challenge the adaptive capabilities of Arctic peoples. In Nunavut, one of Canada's Arctic territories, increased weather variability and changes in physical and climatic conditions are having profound effects on residents. One problem is that while these changes have magnified risks associated with travel and land-based activities, individuals lack sufficiently reliable and useful information on which to base decisions. In this paper, we argue that weather-related risk assessment can be improved by integrating local and scientific weather knowledge and making this information accessible to residents through the creation of weather hazards impact advisory groups. We present a qualitative case study of Iqaluit, the capital of Nunavut, using data from participant observation and semi-structured interviews conducted with indigenous and non-indigenous long-term residents in summer 2009. We examine how long-term residents of Iqaluit acquire, perceive, and use both local and scientific weather knowledge. We find that various barriers, such as a lack of land-based experience, cultural and linguistic differences, and an absence of social networks, prevent most people from obtaining all the information required to make fully informed decisions about the risks associated with land-based activities at different locations. Experienced hunters are perceived to be a reliable source of weather-related information, while scientific weather knowledge is not as accessible or informative as it could be. Increasing the potential use of traditional and scientific hazardous weather knowledge, by making both more universally accessible, can enhance strategies for adapting to climate change in the Arctic. [ABSTRACT FROM AUTHOR]

Research on climate change impacts, vulnerability and adaptation, particularly projects aiming to contribute to practical adaptation initiatives, requires active involvement and collaboration with community members and local, regional and national organizations that use this research for policy-making. Arctic communities are already experiencing and adapting to environmental and socio-cultural changes, and researchers have a practical and ethical responsibility to engage with communities that are the focus of the research. This paper draws on the experiences of researchers working with communities across the Canadian Arctic, together with the expertise of Inuit organizations, Northern research institutes and community partners, to outline key considerations for effectively engaging Arctic communities in collaborative research. These considerations include: initiating early and ongoing communication with communities, and regional and national contacts; involving communities in research design and development; facilitating opportunities for local employment; and disseminating research findings. Examples of each consideration are drawn from climate change research conducted with communities in the Canadian Arctic. [ABSTRACT FROM AUTHOR]

Observed reduction in recent sea ice areal extent and thickness has focused attention on the fact that the Arctic marine system appears to be responding to global-scale climate variability and change. Passive microwave remote-sensing data are the primary source underpinning these reports, yet problems remain in geophysical inversion of information on ice type and concentration. Uncertainty in sea-ice concentration (SIC) retrievals is highest in the summer and fall, when water occurs in liquid phase within the snow-sea-ice system. Of particular scientific interest is the timing and rate of new ice formation due to the control that this form of sea ice has on mass, energy and gas fluxes across the ocean-sea-ice-atmosphere interface. In this paper we examine the critical fall freeze-up period using in situ data from a ship-based and aerial survey programme known as the Canadian Arctic Shelf Exchange study combined with microwave and optical Earth observations data. Results show that: (1) the overall physical conditions observed from aerial survey photography were well matched with coincident moderate-resolution imaging spectroradiometer data and Radarsat ScanSAR imagery; (2) the shortwave albedo was linearly related to old ice concentration derived from survey photography; (3) the three SSM/I SIC algorithms (NASA Team (NT), NASA Team 2 (NT2), and Bootstrap (BT)) showed considerable discrepancies in pixel-scale comparison with the Radarsat ScanSAR SICs well calibrated by the aerial survey data. The major causes of the discrepancies are attributed to (1) the inherent inability to detect the new thin ice in the NT and BT algorithms, (2) mismatches of the thin-ice tie point of the NT2 algorithm, and (3) sub-pixel ambiguity between the thin ice and the mixture of open water and sea ice. These results suggest the need for finer resolution of passive microwave sensors, such as AMSR-E, to improve the precision of the SSM/I SIC algorithms in the marginal ice zone during early fall freeze-up. [ABSTRACT FROM AUTHOR]

Marine tourism in Arctic Canada has grown substantially since 2005. Though there are social, economic and cultural opportunities associated with industry growth, climate change and a range of environmental risks and other problems present significant management challenges. This paper describes the growth in cruise tourism and pleasure craft travel in Canada's Nunavut Territory and then outlines issues and concerns related to existing management of both cruise and pleasure craft tourism. Strengths and areas for improvement are identified and recommendations for enhancing the cruise and pleasure craft governance regimes through strategic management are provided. Key strategic approaches discussed are: (1) streamlining the regulatory framework; (2) improving marine tourism data collection and analysis for decision-making; and (3) developing site guidelines and behaviour guidelines. [ABSTRACT FROM AUTHOR]

Injury is the leading cause of death for Canadians aged 1 to 44, occurring disproportionately across regions and communities. In the Inuit territory of Nunavut, for instance, unintentional injury rates are over three times the Canadian average. In this paper, we develop a framework for assessing vulnerability to injury and use it to identify and characterize the determinants of injuries on the land in Nunavut. We specifically examine unintentional injuries on the land (outside of hamlets) because of the importance of land-based activities to Inuit culture, health, and well-being. Semi-structured interviews (n = 45) were conducted in three communities that have varying rates of search and rescue (SAR), complemented by an analysis of SAR case data for the territory. We found that risk of land-based injuries is affected by socioeconomic status, Inuit traditional knowledge, community organizations, and territorial and national policies. Notably, by moving beyond common conceptualizations of unintentional injury, we are able to better assess root causes of unintentional injury and outline paths for prevention. [ABSTRACT FROM AUTHOR]

Seabirds breeding in the high Arctic contend with variable annual sea ice conditions, with important consequences depending on a species' unique reproductive and foraging ecology. We assessed the influence of sea ice extent and phenology on seabird breeding biology using monitoring data collected for northern fulmar (Fulmarus glacialis), glaucous gull (Larus hyperboreus), black-legged kittiwake (Rissa tridactyla), and thick-billed murre (Uria lomvia) breeding at Prince Leopold Island, Nunavut, Canada over 4 decades. We expected that years of later sea ice break-up and greater ice cover around the colony would create greater challenges to foraging and could result in delayed nest initiation, decreased colony attendance, and lower nesting success, but with distinct responses from each species. We also tested for time-lagged effects of ice conditions, where sea ice in a given year could impact food availability or juvenile recruitment in later years. Ice conditions around the colony exhibited no significant overall temporal trends or changepoints over the past 50 years (1970–2021), while counts of kittiwakes and murres increased over the study period 1975–2013. No trends were evident in counts of fulmars or gulls or in egg-laying dates or nest success for any species. However, three species (all but glaucous gulls) exhibited unique responses between breeding metrics and sea ice, highlighting how breeding decisions and outcomes may differ among species under the same environmental conditions in a given year. Time-lagged effects were only detected for kittiwake nest counts, where the date of spring ice break-up around the colony was negatively associated with counts at a 5-year lag. Greater distances to open water were associated with lower colony attendance by fulmars and later nest initiation by kittiwakes and murres. Our analyses provide additional insights to effects of sea ice on high-Arctic seabird breeding ecology, which will be useful in predicting and planning for the complex effects of a changing climate and changing human pressures on this high-latitude ecosystem and for the management of high-Arctic marine-protected areas. [ABSTRACT FROM AUTHOR]

This paper uses a mixed methods approach to characterise the experience of food insecurity among Inuit community members in Igloolik, Nunavut, and examine the conditions and processes that constrain access, availability, and quality of food. We conducted semi-structured interviews ( n= 66) and focus groups ( n= 10) with community members, and key informant interviews with local and territorial health professionals and policymakers ( n= 19). The study indicates widespread experience of food insecurity. Even individuals and households who were food secure at the time of the research had experienced food insecurity in the recent past, with food insecurity largely transitory in nature. Multiple determinants of food insecurity operating over different spatial-temporal scales are identified, including food affordability and budgeting, food knowledge and preferences, food quality and availability, environmental stress, declining hunting activity, and the cost of harvesting. These determinants are operating in the context of changing livelihoods and climate change, which in many cases are exacerbating food insecurity, although high-order manifestations of food insecurity (that is, starvation) are no longer experienced. [ABSTRACT FROM AUTHOR]

Climate change has broad ecological implications for species that rely on sensitive habitats. For some top predators, loss of habitat is expected to lead to cascading behavioral, nutritional, and reproductive changes that ultimately accelerate population declines. In the case of the polar bear (Ursus maritimus), declining Arctic sea ice reduces access to prey and lengthens seasonal fasting periods. We used a novel combination of physical capture, biopsy darting, and visual aerial observation data to project reproductive performance for polar bears by linking sea ice loss to changes in habitat use, body condition (i.e., fatness), and cub production. Satellite telemetry data from 43 (1991–1997) and 38 (2009–2015) adult female polar bears in the Baffin Bay subpopulation showed that bears now spend an additional 30 d on land (90 d in total) in the 2000s compared to the 1990s, a change closely correlated with changes in spring sea ice breakup and fall sea ice formation. Body condition declined for all sex, age, and reproductive classes and was positively correlated with sea ice availability in the current and previous year. Furthermore, cub litter size was positively correlated with maternal condition and spring breakup date (i.e., later breakup leading to larger litters), and negatively correlated with the duration of the ice‐free period (i.e., longer ice‐free periods leading to smaller litters). Based on these relationships, we projected reproductive performance three polar bear generations into the future (approximately 35 yr). Results indicate that two‐cub litters, previously the norm, could largely disappear from Baffin Bay as sea ice loss continues. Our findings demonstrate how concurrent analysis of multiple data types collected over long periods from polar bears can provide a mechanistic understanding of the ecological implications of climate change. This information is needed for long‐term conservation planning, which includes quantitative harvest risk assessments that incorporate estimated or assumed trends in future environmental carrying capacity. [ABSTRACT FROM AUTHOR]

We present a year‐round time series of dissolved methane (CH4), along with targeted observations during ice melt of CH4 and carbon dioxide (CO2) in a river and estuary adjacent to Cambridge Bay, Nunavut, Canada. During the freshet, CH4 concentrations in the river and ice‐covered estuary were up to 240,000% saturation and 19,000% saturation, respectively, but quickly dropped by >100‐fold following ice melt. Observations with a robotic kayak revealed that river‐derived CH4 and CO2 were transported to the estuary and rapidly ventilated to the atmosphere once ice cover retreated. We estimate that river discharge accounts for >95% of annual CH4 sea‐to‐air emissions from the estuary. These results demonstrate the importance of resolving seasonal dynamics in order to estimate greenhouse gas emissions from polar systems. Plain Language Summary: The primary cause of recent global climate change is increasing concentrations of heat‐trapping greenhouse gases in the atmosphere. Ongoing rapid Arctic climate change is affecting the annual cycle of sea ice formation and retreat; however, most published studies of greenhouse gases in Arctic waters have been conducted during ice‐free, summertime conditions. In order to characterize seasonal variability in greenhouse gas distributions, we collected year‐round measurements of the greenhouse gas methane (CH4) in a coastal Arctic system near Cambridge Bay, Nunavut, Canada. We found that during the ice melt season, river water contains methane concentrations up to 2,000 times higher than the wintertime methane concentrations in the coastal ocean. We utilized a novel robotic kayak to conduct high‐resolution mapping of greenhouse gas distributions during ice melt. From these data, we demonstrate that the river water containing elevated levels of methane and carbon dioxide (CO2) flowed into the coastal ocean, and when ice cover melted, these greenhouse gases were rapidly emitted into the atmosphere. We estimate that in this system, more than 95% of all annual methane emissions from the estuary are driven by river inflow. Key Points: Methane concentrations in an Arctic estuary show strong seasonality; river inflow at the start of the freshet drives elevated concentrationsObservations with a novel robotic kayak demonstrate that methane and carbon dioxide in the estuary are rapidly ventilated following ice meltRiver discharge is estimated to account for >95% of annual methane emissions from the estuary [ABSTRACT FROM AUTHOR]

Anthropogenic noise associated with shipping has emerged as a major disruptor of aquatic animal behavior worldwide. The Arctic marine realm has historically experienced little noise‐generating human activity; however, the continual loss of sea ice has facilitated a dramatic increase in shipping activity. Here, we use a combination of acoustic telemetry and modeling of ship noise to examine the temporospatial habitat use of key Arctic forage fish, Arctic cod (Boreogadus saida) in the presence and absence of vessels in Resolute Bay, Nunavut, Canada. The presence and movement of vessels induced a horizontal shift in the home ranges of Arctic cod with low core overlap when compared to periods without vessel activity. Home range displacement occurred near the vessel. Individuals also altered their swimming behaviors in response to vessel presence with searching decreasing and travelling increasing in proportion. Results indicate that Arctic cod perceive vessel noise and presence as a threat and react by moving away and decreasing exploratory activities. These changes in fish behavior also coincide with the critical open water feeding period suggesting an interruption in exploitation of important and seasonally abundant food resources, and carry broader implications for dependent seabirds and marine mammals, and indirectly for all Arctic indigenous peoples' subsistence and long‐term cultural traditions. Our study implies that strategic management is required for aquatic acoustic disturbance as an environmental stressor in the Arctic marine ecosystem, and highlights ecologically and socially important impacts that require timely conservation action. [ABSTRACT FROM AUTHOR]

Food security is a complex topic defined not just by having enough nutritious food to eat but also by cost, safety and cultural considerations. In Arctic Inuit communities, food security is intimately connected to culture through traditional methods of harvesting country food. In Chesterfield Inlet, Nunavut, community-based research was conducted in collaboration with Chesterfield Inlet community members using interviews and community engagement. Community members were consulted about the design of the interview guide, recruitment of participants, analysis and validation of results. This study aims to develop a theoretical framework of how food security, cultural continuity and community health and well-being are interconnected to allow for a richer understanding of how increased shipping, climate change and social changes are impacting community members. In Chesterfield Inlet, harvesting and consuming country food (e.g., seal) is perceived as the mechanism that connects food, culture and community health. Sharing of freshly harvested country food supports the food security of community members without hunters in their families, aligns with hunters’ cultural beliefs and promotes community health and well-being. Changes that reduce a hunter’s success in harvesting country food limit her or his ability to share country food, which negatively impacts community health and well-being. The results of this study support existing community efforts to adapt to changes that impact harvesting success. [ABSTRACT FROM AUTHOR]

Linear depolarization measurement capabilities were added to the CANDAC Rayleigh-Mie-Raman lidar (CRL) at Eureka, Nunavut, in the Canadian High Arctic in 2010. This upgrade enables measurements of the phases (liquid versus ice) of cold and mixed-phase clouds throughout the year, including during polar night. Depolarization measurements were calibrated according to existing methods using parallel- and perpendicular-polarized profiles as discussed in McCullough et al. (2017). We present a new technique that uses the polarization-independent Rayleigh elastic channel in combination with one of the new polarizationdependent channels, and we show that for a lidar with low signal in one of the polarization-dependent channels this method is superior to the traditional method. The optimal procedure for CRL is to determine the depolarization parameter using the traditional method at low resolution (from parallel and perpendicular signals) and then to use this value to calibrate the high-resolution new measurements (from parallel and polarization-independent Rayleigh elastic signals). Due to its use of two high-signal-rate channels, the new method has lower statistical uncertainty and thus gives depolarization parameter values at higher spatial-temporal resolution by up to a factor of 20 for CRL. This method is easily adaptable to other lidar systems which are considering adding depolarization capability to existing hardware. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate change impacts in the Arctic will be differentiated by gender, yet few empirical studies have investigated how. We use a case study from the Inuit community of Iqaluit, Nunavut, to identify and characterize vulnerability and adaptive capacity of Inuit women to changing climatic conditions. Interviews were conducted with 42 Inuit women and were complimented with focus group discussions and participant observation to examine how women have experienced and responded to changes in climate already observed. Three key traditional activities were identified as being exposed and sensitive to changing conditions: berry picking, sewing, and the amount of time spent on the land. Several coping mechanisms were described to help women manage these exposure sensitivities, such as altering the timing and location of berry picking, and importing seal skins for sewing. The adaptive capacity to employ these mechanisms differed among participants; however, mental health, physical health, traditional/western education, access to country food and store bought foods, access to financial resources, social networks, and connection to Inuit identity emerged as key components of Inuit women's adaptive capacity. The study finds that gender roles result in different pathways through which changing climatic conditions affect people locally, although the broad determinants of vulnerability and adaptive capacity for women are consistent with those identified for men in the scholarship more broadly. [ABSTRACT FROM AUTHOR]

Climate change, the global demand for energy, and the depletion of easily accessible natural resources has led to an increase in mining activities in the Arctic, including in Nunavut, a region rich in resources but remote in comparison to the rest of Canada. Nunavut is a predominantly Inuit socio-political region created in 1999 via the Nunavut Act and the Nunavut Land Claims Agreement (NLCA) (1993). The NLCA also enshrined the Inuit right to manage the region's minerals and other natural resources. Yet, despite this power to "steer their own ship," Inuit communities struggle to maximize the benefits from resource development. Pond Inlet is a coastal hamlet on Baffin Island close to the newly operational Mary River iron ore mine, an open-pit mine with the potential to bring significant economic opportunities to the region. Using a framework developed by the Harvard Project on American Indian Economic Development, a case study of Pond Inlet highlights factors that contribute to and hinder Arctic Aboriginal communities' successful local development. A total of 47 semi-structured interviews were conducted with key informants in Pond Inlet and in the territory's capital, Iqaluit. Findings underscore the importance of Indigenous community self-determination, effective and culturally relevant governing institutions, and clear visioning for the future. In Pond Inlet, key barriers to maximizing local benefits relate to institutional and governance challenges. Evidence from this study suggests that Pond Inlet will better succeed with local community development by strengthening its governance mechanisms to support the goals of self-determination. [ABSTRACT FROM AUTHOR]

Climate change has been identified as a major driver of habitat change, particularly for sea ice-dependent species such as the polar bear ( Ursus maritimus). Population structure and space use of polar bears have been challenging to quantify because of their circumpolar distribution and tendency to range over large areas. Knowledge of movement patterns, home range, and habitat is needed for conservation and management. This is the first study to examine the spatial ecology of polar bears in the Foxe Basin management unit of Nunavut, Canada. Foxe Basin is in the mid-Arctic, part of the seasonal sea ice ecoregion and it is being negatively affected by climate change. Our objectives were to examine intrapopulation spatial structure, to determine movement patterns, and to consider how polar bear movements may respond to changing sea ice habitat conditions. Hierarchical and fuzzy cluster analyses were used to assess intrapopulation spatial structure of geographic position system satellite-collared female polar bears. Seasonal and annual movement metrics (home range, movement rates, time on ice) and home-range fidelity (static and dynamic overlap) were compared to examine the influence of regional sea ice on movements. The polar bears were distributed in three spatial clusters, and there were differences in the movement metrics between clusters that may reflect sea ice habitat conditions. Within the clusters, bears moved independently of each other. Annual and seasonal home-range fidelity was observed, and the bears used two movement patterns: on-ice range residency and annual migration. We predict that home-range fidelity may decline as the spatial and temporal predictability of sea ice changes. These new findings also provide baseline information for managing and monitoring this polar bear population. [ABSTRACT FROM AUTHOR]

Adaptation readiness is proposed as a complimentary concept to adaptive capacity that captures the strength and existence of governance structures and policy processes which determine whether adaptation takes place. As such, adaptation readiness is concerned with examining actual experiences with planning for adaptation and seeks to characterize whether human systems are prepared and ready to 'do adaptation.' We propose a framework for evaluating readiness, identifying 6 overarching factors essential for adaptation taking place: political leadership, institutional organization, adaptation decision making and stakeholder engagement, availability of usable science, funding for adaptation, and public support for adaptation. For each readiness factor we identify potential indicators, data sources, and considerations for analysis, outlining approaches for quantitative scoring and qualitative examination. We briefly illustrate application of the framework using an example from the territory of Nunavut in the Canadian Arctic, a region projected to experience some of the most dramatic changes in climate globally this century. The framework provides a systematic approach for assessing adaptation readiness, and can be used - in combination with other approaches - to inform the identification and prioritization of adaptation support, guide resources to areas where need is greatest, and serve as a proxy for adaptation tracking. [ABSTRACT FROM AUTHOR]

Estimating regional-scale rates of glacier mass change from repeat airborne and satellite altimetry requires assumptions about the density of the material being added to, or removed from, the glacier surface. This may vary in both space and time, especially in a period of warming climate such as has occurred in Arctic Canada since 2005. Here we compare firn properties measured on 20 shallow cores recovered from elevations of 1400-1900 ma.s.l. on Devon Ice Cap in 2012 with equivalent measurements from 34 cores recovered from the same locations between 2004 and 2011. The average density of the top 2.5 m of the firn column has increased by 13-80%. As a result, measured rates of density increase in the top 1.25 m w.e. of the firn layer have likely thinned this layer at rates of 0.021-0.168ma-1 over the period 2004-12. These thinning rates are significant relative to local rates of surface height change measured by repeat airborne laser altimetry between 2004 and 2012 (-0.077 to -0.252ma-1) and indicate that, during periods of climate warming or cooling, firn densification rate changes must be taken into account when estimating mass change rates from measured height changes. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Core 86027-144 (74°15.56′ N, 91°14.21′ W) represents a rare, continuous record of Late Pleistocene to Holocene sediments from High Arctic Canada extending from the end of the Last Glaciation. Based on microfossils (dinocysts, non-pollen palynomorphs, benthic and planktonic foraminifera), foraminiferal δ18O and δ13C, and sedimentology, seven palaeoenvironmental zones were identified. Zone I (>10.8 cal. ka BP) records deglaciation, ice-sheet destabilization, float-off and subsequent break-up. Zone II ( c. 10.8-10.4 cal. ka BP) shows ice-proximal to ice-distal glaciomarine conditions, interrupted by pervasive land-fast sea-ice marked by a hiatus in coarse sediment deposition. Significant biological activity starts in Zone III (10.4-9.9 cal. ka BP), where planktonic foraminifera ( N eogloboquadrina pachyderma) suggest early oceanic throughflow. Surface waters flowed NW-SE; however, the deep-water origin remains unclear (potentially NW Arctic Ocean or Baffin Bay). Postglacial amelioration (open-water season greater than present) in Zone IV (9.9-7.8 cal. ka BP) perhaps corresponds to the regional 'Holocene Thermal Maximum' previously proposed. A transitional period (Zone V; 7.8-6.7 cal. ka BP) of rapid environmental change fluctuating on a scale not observed today is marked by increasing sea-ice and reduced oceanic influence. This probably signals the exclusion of deeper Atlantic water owing to the glacio-isostatic shallowing of inter-island sills, coupled with generally cooling climate. Conditions analogous to those at present, with increased sea-ice and modern microfossil assemblages, commence at c. 6.7 cal. ka BP (zones VI- VII). Although climate ultimately forces long-term environmental trends, core 86027-144 data imply that regional dynamics, especially changes in sea-level, exert a significant control on marine conditions throughout the Canadian Arctic Archipelago. [ABSTRACT FROM AUTHOR]

Ice shelves in the Arctic lost more than 90% of their total surface area during the 20th century and are continuing to disintegrate rapidly. The significance of these changes, however, is obscured by the poorly constrained ontogeny of Arctic ice shelves. Here we use the sedimentary record behind the largest remaining ice shelf in the Arctic, the Ward Hunt Ice Shelf (Ellesmere Island, Canada), to establish a long-term context in which to evaluate recent ice-shelf deterioration. Multiproxy analysis of sediment cores revealed pronounced biological and geochemical changes in Disraeli Fiord in response to the formation of the Ward Hunt Ice Shelf and its fluctuations through time. Our results show that the ice shelf was absent during the early Holocene and formed 4,000 years ago in response to climate cooling. Paleoecological data then indicate that the Ward Hunt Ice Shelf remained stable for almost three millennia before a major fracturing event that occurred ~1,400 years ago. After reformation ~800 years ago, freshwater was a constant feature of Disraeli Fiord until the catastrophic drainage of its epishelf lake in the early 21st century. [ABSTRACT FROM AUTHOR]

Climate change in the Canadian north is, and will be, managed by communities that are already experiencing social, political, economic and other environmental changes. Hence, there is a need to understand vulnerability to climate change in the context of multiple exposure-sensitivities at the community level. This article responds to this perceived knowledge need based on a case study of the community of Kugluktuk in Nunavut, Canada. An established approach for vulnerability assessment is used to identify current climatic and non-climatic exposure-sensitivities along with their associated contemporary adaptation strategies. This assessment of current vulnerability is used as a basis to consider Kugluktuk's possible vulnerability to climatic change in the future. Current climate-related exposure-sensitivities in Kugluktuk relate primarily to subsistence harvesting and community infrastructure. Thinner and less stable ice conditions and unpredictable weather patterns are making travel and harvesting more dangerous and some community infrastructure is sensitive to permafrost melt and extreme weather events (e.g., flash floods). The ability of individuals and households to adapt to these and other climatic exposure-sensitivities is influenced by non-climatic factors that condition adaptive capacity including substance abuse, the erosion of traditional knowledge and youth suicide. These and other non-climatic factors often underpin adaptive capacity to deal with and adapt to changing conditions and must be considered in an assessment of vulnerability. This research argues that Northern communities are challenged by multiple exposure-sensitivities--beyond just those posed by climate--and effective adaptation to climate change requires consideration if not resolution of socio-economic and other issues in communities. [ABSTRACT FROM AUTHOR]

Stygge Nunatak Pond is a small, shallow, closed-basin pond situated on a nunatak in Stygge Glacier at the head of Jokel Fiord, east-central Ellesmere Island, Nunavut, Canada. Its ionic concentration is unusually high by inland Arctic standards, with specific conductivity measured at up to 1,090 μS/cm, making this site a rare example of a subsaline athalassic Arctic pond. Small, closed-basin lakes and ponds are particularly sensitive to changes in the balance between precipitation and evaporation (P-E), which affect the site's chemical, physical and biological characteristics. Such lakes and ponds therefore have the potential to serve as sensitive archives of past environmental change, which can be reconstructed using paleolimnological techniques. Diatom assemblages from two sediment cores (a short gravity core [21.5 cm] and a long core of frozen material [387 cm]) were examined so as to reconstruct regional environmental changes. Basal radiocarbon dating of the long core suggests that the pond has existed since before 10,500 cal. year BP. The diatom assemblages from both cores record similar ecological changes since approximately 2,200 cal. year BP, with a stable, coldwater assemblage dominated by Fragilaria construens var. venter. This assemblage was replaced in the early- to mid-20th century by dramatic, unprecedented expansion in periphytic taxa with more complex life forms, especially Cymbella descripta, Navicula halophila and Achnanthes minutissima. These assemblage shifts are indicative of recent warming, with a longer open-water period, expanded littoral substrates, and increased ionic concentration, as would be expected with enhanced evaporation relative to precipitation. Between ~10,500 and ~6,200 cal. year BP, the diatom assemblages underwent a shift from a near monoculture of F. construens var. venter to a more complex, epiphytic assemblage, which then reverted back to the former virtual monoculture. These shifts may provide further evidence for an early Holocene thermal maximum in this region of the Arctic, followed by Neoglacial cooling. However, interpretation of assemblages before ~6,200 cal. year BP is complicated by the fact that the sediment beneath 47 cm depth is unconsolidated and embedded within a core of solid ice, a feature that has not been reported in any other Arctic paleolimnological study to date. Superficial examination of the contact surfaces of the ice, and the fact that radiocarbon ages obtained from entrained sediment are chronologically consistent with those from the sediment above, suggest that the ice might be intrasedimental segregation ice. [ABSTRACT FROM AUTHOR]

Environmental change has stressed wildlife co-management systems in the Arctic because parameters are changing more rapidly than traditional scientific monitoring can accommodate. Co-management systems have also been criticized for not fully integrating harvesters into the local management of resources. These two problems can be approached through the use of spatially-defined human social units termed community clusters, which are based on the demographic or ecological units being managed. An examination of polar bear management in Nunavut Territory, Canada, shows that community clusters provide a forum to collect and analyse traditional ecological knowledge (TEK) over a geographic area that mirrors the management unit, providing detailed information of local conditions. This case study also provides examples of how instituting community clusters at a governance level provides harvesters with social space in which to develop their roles as managers, along the continuum from being powerless spectators to active, adaptive co-managers. Five steps for enhancing co-management systems through the inclusion of community clusters and their knowledge are: (1) the acceptance of TEK, science, the precautionary principle and the right of harvesters not to be constrained by overly-conservative management decisions; (2) data collection involving TEK and science, and a collaboration between the two; (3) institutionalization of community clusters for data collection; (4) institutionalization of community clusters in the management process; and (5) grass-roots initiatives to take advantage of the social space provided by the community cluster approach, in order to adapt the management to local conditions, and to effect policy changes at higher levels, so as to better meet local objectives. [ABSTRACT FROM AUTHOR]

Previous studies have identified finely laminated, or layered, features within Arctic clouds. This study focuses on quasi-horizontal layers that are 7.5 to 30 m thick, within clouds from 0 to 5 km altitude. No pre-selection for any particular cloud types was made prior to the identification of laminations. We capitalize on the 4-year measurement record available from Eureka, Nunavut (79.6 ∘ N, 85.6 ∘ W), using the Canadian Network for the Detection of Atmospheric Composition Change (CANDAC) Rayleigh–Mie–Raman Lidar (CRL; 1 min, 7.5 m resolution). Laminated features are identified on 18% of all days, from 2016–2019. Their presence is conclusively excluded on 12% of days. March, April, and May have a higher measurement cadence and show laminations on 41% of days. Individual months show laminations on up to 50% of days. Our results suggest that laminations are not rare phenomena at Eureka. To determine laminations' likely contribution to Arctic weather and climate, local weather reports were obtained from the nearby Environment and Climate Change Canada (ECCC) weather station. Days with laminated clouds are strongly correlated with precipitating snow (r = 0.63), while days with non-laminated clouds (r = −0.40) and clear sky days (r = −0.43) are moderately anti-correlated with snow precipitation. [ABSTRACT FROM AUTHOR]

This article cites a study which described the occurrence and behavior of Razorbills visiting Coats Island, Northern Hudson Bay. Researchers found no evidence that Razorbills actually bred. Researchers observed that Razorbills seem to have tracked the appearance of their usual prey so quickly. Observations by researchers support the idea that Razorbills may readily disperse over long distances and lead them to conclude that it will be hard for biologists to predict the range expansions that are likely to occur in the short term due to climate change.

Concerns about the effects of global warming on Arctic environments have stimulated multidisciplinary research into the history of their long-term climatic and environmental variability to improve future predictions of climate in these remote areas. Here we present the first palaeolimnological study for Southampton Island using analyses of chironomids supported by sedimentological analyses, carried out on a 1 m long core retrieved from a lake located in the northeastern part of the island. This core was made up of marine sediments underneath 65 cm of freshwater lake sediments. A marine shell, humic-acids and chironomid head capsules were used to date this sequence. The Holocene environmental history of the lake consisted of two major contrasting periods. The first one, between about 5570 and 4360 cal. yr BP, was climatically unstable, with common postglacial chironomid taxa such as Corynocera oliveri-type, Paracladius and Microspectra radialis-type. This period also corresponded to the highest chironomid-inferred August air temperature (10°C) for the whole record and to significant increases in major chemical elements as detected by x-ray fluorescence. During the second period, which lasted from about 3570 cal. yr BP until the present, limnological conditions seemed to stabilize after a change to cold oligotrophic chironomid taxa, such as Heterotrissocladius subpilosus-group, with no major variations in the abundance of chemical elements. Inferred August air temperatures ranged between 8 and 9°C. This study provided unique information on the timing of the Holocene Thermal Maximum in the Foxe Basin area, a region with very little information available on long-term climate change. This region showed, so far, relatively few signs of recent climatic change, as opposed to other regions in the High Arctic. [ABSTRACT FROM AUTHOR]

1 The response of peat-rich permafrost soils to human-induced climate change may be especially important in modifying the global C-flux. We examined the Holocene developmental record of a High Arctic peat-forming wetland to investigate its sensitivity to past climate change and aid understanding of the likely effects of future climate warming on high-latitude ecosystems. 2 The microhabitat of mosses was quantified in the present-day polygon-complex at Bylot Island (73° N, 80° W) and used to interpret the radiocarbon-dated macrofossil record of three cores, comprising c. 3500 years of wetland development. Recurrent wet and dry phases in the reconstructed palaeohydrological record indicated pronounced temporal variability. Wet and dry phases were compared between cores and with palaeoclimatic proxy values, measured as percentage melt and δ18O in nearby ice cores. 3 Periodic wet and dry phases appear unrelated to past climate over c. 50% of the combined stratigraphic records, and are attributable instead to geomorphological mechanisms. At other times, association of wet and dry phases with significantly lower and higher values of percentage melt and δ18O indicate a possible effect of past climate change on polygon hydrology and vegetation, although inconsistencies between cores suggest that local geomorphological processes continued to modify a regional climatic effect. However, during a period incorporating the Little Ice Age ( c. 305–530 cal. yearsbp), reconstructed moisture and vegetation change is pronounced and consistent among all three cores. 4 The results provide strong evidence for the sensitivity of a High Arctic terrestrial ecosystem to past climate change during the Holocene. The estimated magnitude of changes in soil moisture between wet and dry phases is sufficient to imply recurrent shifts in wetland function, periodically impacted upon by pronounced climatic variability, although controlled principally by autogenic processes. The structure and function of such wetlands may therefore be susceptible to predicted, human-induced climate warming. [ABSTRACT FROM AUTHOR]

We present the normal baseline variation in haematology of 59 Northern Fulmars ( Fulmarus glacialis) collected from two high arctic sites in Nunavut, Canada. We found no differences between males and females in any haematological variable, but leukocyte profiles differed between non-breeding and breeding birds and also between breeding birds at different colonies. Breeding birds also had higher thrombocyte counts than non-breeders. Given that the Arctic is experiencing significant environmental changes due to climate warming, reference haematological values from seabirds may prove useful in monitoring the impacts on arctic ecosystems. [ABSTRACT FROM AUTHOR]

Diatoms were examined in three lacustrine sediment records from Alert, northern Ellesmere Island, and from Isachsen, Ellef Ringnes Island. Diatom assemblages changed markedly since the mid-19th century following relatively stable community composition that spanned centuries to millennia. Three different assemblages, primarily composed of Fragilaria pinnata, Diadesmis spp., or Pinnularia spp., dominated the pre-1850 period at the three sites, but were replaced with different, more diverse assemblages in recent sediments. These species shifts occurred in the mid- to late-19th century in the Isachsen sites, and in the mid- to late-20th century in our Alert site. This difference in timing appears to be a result of the different sensitivities of lakes and ponds to environmental change, rather than of site-specific chemical properties. Reconstructions of pH using diatom inference models indicated increases from 0.5 to 0.8 pH units at these sites over this period of assemblage change. The diatom-inferred pH record from Alert showed agreement with measured climate data from Alert over the last ∼30 years. These marked community changes suggest that these sensitive high arctic sites have recently crossed important ecological thresholds due to environmental change, most likely related to recent warming. [ABSTRACT FROM AUTHOR]

A 485cm sediment core from a lake unofficially called JR01, Boothia Peninsula, Nunavut, Canada, yielded a high-resolution diatom record documenting environmental change in the mid-arctic. Five radiocarbon dates provided the chronology. Changes in diatom composition and sediment characteristics indicated distinct shifts in the Holocene climate. A more diverse and productive diatom flora implies warmer temperatures in the middle Holocene. A subsequent complete shift in diatom composition to a predominantly Fragilaria sensu lato flora and a reduction in diversity and production suggests cooler climates in this region after 4600cal. BP. Smaller-scale climatic fluctuations, such as the 'Little Ice Age'(LIA, 600-150cal. BP) and the 'Mediaeval Warm Period' (MWP, 1150-600cal. BP), caused shifts in the diatom flora and production. Subtle shifts in floristic diversity within the LIA may reflect climatic variability at a century scale. A gradual shift to a more diverse and productive flora in the last 150 years suggests a response to the recent warming trend. [ABSTRACT FROM AUTHOR]