PURPOSE:Given the paucity of information on Arctic char along western Hudson Bay, in 2018, Fisheries and Oceans Canada (DFO) hosted an Arctic char workshop in Rankin Inlet, Nunavut, bringing together local resource users, knowledge holders, and co-management groups (e.g., Hunters and Trappers Organizations, Regional Wildlife Organization) to identify and discuss community-based Arctic char research priorities across the Kivalliq region of Nunavut. Communities were especially interested in examining “what Arctic char were eating” and “why the colour of their muscle is different” along the western Hudson Bay coastline, and in the summer of 2018, a regional community-based Arctic char monitoring program was implemented across the region. DESCRIPTION:Climate-induced alterations to Arctic sea ice dynamics are influencing the availability and distribution of resources, and in turn, the nutrient and energy intake of opportunistic predators across the food web. These temporal changes in local prey communities likely influence the availability of carotenoid-rich prey types, as well as the foraging ecology of opportunistic predators that forage in the marine environment, such as anadromous Arctic char (Salvelinus alpinus). Despite its socioeconomic importance across its range, anadromous Arctic char foraging ecology and its influence on muscle pigmentation, particularly in relation to sea ice dynamics, remains understudied. Here, over two years (2021, 2022) with contrasting sea ice dynamics, we investigated the foraging ecology of anadromous Arctic char and its influence on their muscle pigmentation at a southern (Rankin Inlet) and northern (Naujaat) location along western Hudson Bay using a combination of stomach contents, stable isotopes (δ¹³C and δ¹⁵N), highly branched isoprenoids, carotenoid spectrophotometry, and a standard muscle colour scale (DSM SalmoFan). Spatiotemporal variation in Arctic char diet occurred, where Rankin Inlet Arctic char generally consumed more fish and phytoplankton-based carbon sources, occupied a higher trophic position, and displayed a similar isotopic niche breadth compared to Arctic char in Naujaat. Invertebrates were higher in carotenoid concentration than fishes, and in association with a more invertebrate-based diet, Arctic char in Naujaat contained higher muscle carotenoid concentrations (e.g., astaxanthin) compared to Rankin Inlet Arctic char in 2021. In 2022, however, muscle carotenoid concentrations in Naujaat and Rankin Inlet Arctic char were more similar, as the diet of Arctic char in both locations was largely fish-based despite muscle colour remaining redder in Naujaat Arctic char. Overall, the observed plastic foraging ecology of Arctic char highlights this species' ability to adjust to inter-annual variability in environmental changes, which then impacts their muscle carotenoid concentration. Such inter-annual variation in Arctic char foraging ecology is anticipated to increase with unpredictable climate-driven environmental changes in the region, which could therefore negatively affect local resource users over the long term, resulting in socioeconomic impacts across the Arctic.Collection/sampling methodology:Arctic char were collected by angling and gillnetting (5.5” mesh, regularly checked) between June and August in the estuarine and marine environments near the communities of Rankin Inlet and Naujaat, Nunavut. In 2021, Naujaat Arctic char were collected by community fishers as part of a community-based sampling program. Concurrently, invertebrate prey types were opportunistically collected in the vicinity of Arctic char sampling sites using a conical zooplankton net (200-μm mesh; 10-minute tows) or obtained fresh from Arctic char stomachs. Additionally, marine fishes were opportunistically collected by angling or obtained fresh from Arctic char stomachs over both years in Rankin Inlet, while samples from the Naujaat area were collected in 2018 and 2019.The Kivalliq Wildlife Board (Rankin Inlet, NU) and Arviq Hunters and Trappers Association (Naujaat, NU) each supported this community-formulated research project and assisted with sample collections throughout the duration of the project. We would like to recognize and thank Sonny Ittinuar (Kivalliq Wildlife Board/Rankin Inlet Local Resource User), Clayton Tartak (Kivalliq Wildlife Board), Vincent L’Herault (ArctiConnexion), and Gail Davoren (University of Manitoba MSc co-supervisor) for their participation in the project. We would also like to thank Sonny Ittinuar, Poisey (Adam) Alogut, John-El, Peter, Quassa, and Goretti Tinashlu, who assisted in field work. USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

The High Arctic dataset comes from the Petroleum and Environmental Management Tool (PEMT). The online tool was decommissioned in 2019 and the data was transferred to Open Data in order to preserve it.The PEMT was originally developed in 2009 to help guide development in the Canadian Arctic by Indian and Northern Affairs Canada (INAC). The online tool mapped the sensitivities of a variety of Arctic features, ranging from whales to traditional harvesting, across the Arctic. The tool was intended to aid government, oil and gas companies, Aboriginal groups, resource managers and public stakeholders in better understanding the geographic distribution of areas which are sensitive for environmental and socio-economic reasons. The study area is located in the High Arctic Archipelago and contains both marine and terrestrial components. The boundaries of the study area are based on the NOGB leasing grids applied in the High Arctic, under which exploration, significant discovery and production licenses may be issued. The Sverdrup Basin (and Lancaster Sound) has the highest known oil and gas potential of the sedimentary basins of the Arctic Islands (Nunavut Planning Commission 2000) and it is expected that there is oil and gas potential on Melville Island and Bathurst Island (Sivummut Economic Development Strategy Group 2003). To date, no gas has been produced, and 321,470 m³ of oil has been produced from the Bent Horn oil field (Morrell et al. 1995). DISCLAIMER: Please refer to the PEMT Disclaimer document or the Resource Constraints - Use Limitation in the Additional Information section below.Note: This is one of the 3 (three) datasets included in the PEMT application which includes the Beaufort Sea and Mackenzie Delta and Eastern Arctic datasets.

In 2018, Fisheries and Oceans Canada initiated the Multidisciplinary Arctic Program (MAP) – Last Ice, the first ecosystem study of the poorly characterized region of Tuvaijuittuq, where multiyear ice still resides in the Arctic Ocean. The program MAP-Last Ice takes a coordinated approach to integrate the physical, biochemical, and ecological components of the sea ice-ocean connected ecosystem and its response to climate and ocean forcings. This program provides baseline ecological knowledge for Tuvaijuittuq and, in particular, for its unique multiyear ice ecosystem. The database provides baseline data on fatty acid composition and stable isotopes signatures of sea ice communities in multi- and first-year ice in Tuvaijuittuq. The data were collected during the 2018 spring field campaign of the MAP-Last Ice Program, offshore of Canadian Forces Station (CFS) Alert, in the Lincoln Sea.

The Eastern Arctic dataset comes from the Petroleum and Environmental Management Tool (PEMT). The online tool was decommissioned in 2019 and the data was transferred to Open Data in order to preserve it.The PEMT was originally developed in 2009 to help guide development in the Canadian Arctic by Indian and Northern Affairs Canada (INAC). The online tool mapped the sensitivities of a variety of Arctic features, ranging from whales to traditional harvesting, across the Arctic. The tool was intended to aid government, oil and gas companies, Aboriginal groups, resource managers and public stakeholders in better understanding the geographic distribution of areas which are sensitive for environmental and socio-economic reasons. The study area is located east of Baffin Island, Nunavut and encompasses marine habitat in Baffin Bay and Davis Strait. The boundaries of the study area are based on NOGB leasing grids applied in the Eastern Arctic, under which exploration and production licenses may be issued. Although portions of the study area hold high oil and gas potential and several small oil fields and substantial reserves of gas have been found since the 1960s in the north Baffin region, exploration for oil and gas has been limited to seismic operations and geological field work.DISCLAIMER: Please refer to the PEMT Disclaimer document or the Resource Constraints - Use Limitation in the Additional Information section below.Note: This is one of the 3 (three) datasets included in the PEMT application which includes the Beaufort Sea and Mackenzie Delta and High Arctic datasets.

The St. Lawrence Estuary is known as a summer foraging area for several species of marine mammals, including several species of rorquals. Among these is the blue whale, which feeds almost exclusively on euphausiids. Therefore, the abundance, distribution and local density of krill should logically be a strong explanatory variable for the distribution of blue whales. However little is known about the spatial association of blue whales with the aggregation dynamics of krill in eastern Canada. Six years of acoustic surveys, conducted in August from 2009 to 2014, were undertaken to study the medium- and small-scale distribution of krill within the northwestern Gulf of St. Lawrence and estuary. The data shows a mosaic of the maximum annual density of arctic krill (T. raschii) made from these surveys.McQuinn, I.H., Gosselin, J.-F., Bourassa, M.-N., Mosnier, A., St-Pierre, J.-F., Plourde, S., Lesage, V., Raymond, A. 2016. The spatial association of blue whales (Balaenoptera musculus) with krill patches (Thysanoessa spp. and Meganyctiphanes norvegica) in the estuary and northwestern Gulf of St. Lawrence. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/104. iv + 19 p.

Across the Canadian North, Arctic Char, Salvelinus alpinus, are culturally important and critical for maintaining subsistence lifestyles and ensuring food security for Inuit. Arctic Char also support economic development initiatives in many Arctic communities through the establishment of coastal and inland commercial char fisheries. The Halokvik River, located near the community of Cambridge Bay, Nunavut, has supported a commercial fishery for anadromous Arctic Char since the late 1960s. The sustainable management of this fishery, however, remains challenging given the lack of biological data on Arctic Char from this system and the limited information on abundance and biomass needed for resolving sustainable rates of exploitation. In 2013 and 2014, we enumerated the upstream run of Arctic Char in this system using a weir normally used for commercial harvesting. Additionally, we measured fish length and used T-bar anchor tags to mark a subset of the run. Subsequently, we estimated population size using capture-mark-recapture (CMR) methods. The estimated number of Arctic Char differed substantially between years. In 2013, 1967 Arctic Char were enumerated whereas in 2014, 14,502 Arctic Char were enumerated. We attribute this marked difference primarily to differences in weir design between years. There was also no significant relationship between daily mean water temperature and number of Arctic Char counted per day in either year of the enumeration. The CMR population estimates of Arctic Char (those ≥450mm in length) for 2013 and 2014 were 35,546 (95% C.I 30,513-49,254) and 48,377 (95% C.I. 37,398-74,601) respectively. The 95% CI overlapped between years, suggesting that inter-annual differences may not be as extreme as what is suggested by the enumeration. The population estimates reported here are also the first estimates of population size for an Arctic Char stock in the Cambridge Bay region using CMR methodology. Overall, the results of this study will be valuable for understanding how population size may fluctuate over time in the region and for potentially providing advice on the sustainable rates of harvest for Halokvik River Arctic Char. Additionally, the results generated here may prove valuable for validating current stock assessment models that are being explored for estimating biomass and abundance for commercial stocks of Arctic Char in the region.

In 2021, the Canada Coast Guard (CCG) and Fisheries and Oceans Canada updated its administrative boundaries following the creation a new Arctic region. There are now 4 administrative regions in CCG (Western, Arctic, Central and Atlantic). DFO and Coast Guard Arctic Regions developed these regions in partnership with the people they serve; this important decision will lead to stronger programs and services to better meet the unique needs of our Arctic communities. DFO and CCG operations and research cover Canada's land and waters to the international boundaries (EEZ) and are in no way limited to the boundaries drawn in the map.

Records of marine mammal sightings (N = 5,324) collected by ASOs and submitted to Fisheries and Oceans Canada (DFO) between 1979-2024, across three DFO regions: the Arctic, Newfoundland and Labrador, and the Maritimes. Methods for initial data compilation are provided in the associated technical report "Marine mammal records collected by the at-sea observer (ASO) program in Arctic, Newfoundland and Labrador, and Maritimes regions: a summary of challenges and opportunities for future research." Cite this data as: Feyrer, L.J., Colbourne, N., Lawson, J.W., Moors-Murphy, H.B., Ferguson, S. Dataset update to Marine mammal records collected by the At-Sea Observer program in Arctic, Newfoundland and Labrador and Maritimes regions. Published: February 2025. Ocean Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S.

PURPOSE:The focus of this research is on changes in the distribution of killer whales in the Canadian Arctic, which is within the field of marine biogeography and marine megafauna. Our research details change in killer whale presence and ties it to changes in sea ice coverage. These are novel results, presenting trends in the arrival and departure dates of killer whales into the eastern Canadian Arctic for the first time. We go on to discuss the impacts of these changes on other aspects of Arctic ecosystems and how increasing in killer whale presence might affect other species and the management of those species in Canada. Killer whales are a widespread species of interest, especially in the Canadian Arctic as their presence is tied to multiple aspects of a region rapidly changing from the effects of climate change. DESCRIPTION:This study examines 20 years of killer whale (Orcinus orca) sightings in the eastern Canadian Arctic, drawing from a comprehensive sighting database spanning 1850-2023. Despite inherent biases favoring data collection near communities and coastal areas, spatiotemporal analyses reveal significant shifts in killer whale distribution linked to changing sea ice conditions. We developed a clustering metric representing the mean distance to the five nearest sightings and results show that killer whales are progressively moving away from historically high-use areas and that sighting locations are becoming more dispersed over time. A significant year × sea ice interaction indicates observations occur earlier during their arrival period at lower sea ice concentrations over time, suggesting that declining sea iceconcentration contributes to earlier arrival. Conversely, for departure periods, killer whales are observed farther south later in the year, likely linked to earlier freeze-up at higher latitudes, and are overall observed later into the year over time. This trend has led to a near doubling of their average presence from 26 days in 2002 to 48 days in 2023 (27 July to 13 September) reflecting an extended open-water season. These findings underscore the prolonged seasonal use of Arctic regions by killer whales, driven by diminishing sea ice and expanding openwater habitat. Such shifts highlight potential implications for Arctic marine ecosystems as killer whales increasingly overlap with endemic species.

The Beaufort Sea and Mackenzie Delta dataset comes from the Petroleum and Environmental Management Tool (PEMT). The online tool was decommissioned in 2019 and the data was transferred to Open Data in order to preserve it.The PEMT was originally developed in 2009 to help guide development in the Canadian Arctic by Indian and Northern Affairs Canada (INAC). The online tool mapped the sensitivities of a variety of Arctic features, ranging from whales to traditional harvesting, across the Arctic. The tool was intended to aid government, oil and gas companies, Aboriginal groups, resource managers and public stakeholders in better understanding the geographic distribution of areas which are sensitive for environmental and socio-economic reasons. The study area and analytical resolution was defined using the oil and gas leasing grid within the Beaufort Sea. The study area has been the scene of oil and gas exploration activity since 1957. Oil was first discovered at Atkinson Point in 1969 and major gas fields in the early 1970s. Such finds spurred the proposal of the Mackenzie Valley Pipeline in 1974 and the addition of exploration and investment offshore. Exploration and drilling continued both onshore and offshore until the mid-1970s with the release of the Berger Report, which recommended a 10-year moratorium on the construction of the pipeline. After the release of the Berger Report, the pace of onshore activity declined but offshore exploration escalated in the 1980s. Offshore exploration was facilitated with innovative operating techniques and new offshore platforms that extended the ability to operate in the short open-water season and ice. With the minor exception of the small onshore gas field at Ikhil, no oil or gas has been commercially produced in the area.DISCLAIMER: Please refer to the PEMT Disclaimer document or the Resource Constraints - Use Limitation in the Additional Information section below.Note: This is one of the 3 (three) datasets included in the PEMT application which includes the High Arctic and Eastern Arctic datasets.