Arctic Science

Arctic Science, Volume 10, Issue 3, Page 511-519, September 2024. <br/> The occurrence of the invasive pink salmon (Oncorhynchus gorbuscha, Walbaum 1792) in Greenland was initially described in 2019 using social media to collect data on their presence. In this study we continue data collection through social media and initiate a monitoring program of the Kapisillit River in Southwest Greenland using snorkeling and environmental DNA (eDNA) metabarcoding in 2020 and 2021. The Kapisillit River is the only freshwater system in Greenland, where the red-listed Atlantic salmon (Salmo salar, Linnaeus 1758) is known to spawn. This genetically unique population of Atlantic salmon has been found to decline, wherefore there is general conservation concern that the occurrence of pink salmon at some point can become an additional stressor to the “Kapisillit salmon”. In 2021, pink salmon were present near all larger populated areas in Greenland and likely more abundant than in 2019. From visual observations and using eDNA, the presence of pink salmon was documented in the Kapisillit River in 2021. From the number of individuals observed combined with the spatial distribution of eDNA detections in the river, we suggest that the pink salmon invasion in the Kapisillit River is at an early stage.

Arctic Science, Ahead of Print. <br/> Indigenous-driven and community-partnered research projects seeking to develop salient, legitimate, and credible knowledge bases for environmental decision-making require a multiple knowledge systems approach. When involving partners in addition to communities, diverging perspectives and priorities may arise, making the pathways to engaging in principled research while generating actionable knowledge unclear to disciplinarily-trained natural science researchers. Here, we share insights from the Eeyou Coastal Habitat Comprehensive Research Project (CHCRP), an interdisciplinary, Cree-driven community-academic partnership. This project brought together Cree community members, regional organizations, industry (Hydro-Québec), and academics from seven universities across Canada to address the unprecedented loss of seagrass Zostera marina (eelgrass), the concurrent decline in migratory Canada geese and its impact on fall goose harvest activities in Eeyou Istchee. After describing the history and context of the project, we discuss the challenges, complexities, and benefits of the collaborative approach balancing saliency, legitimacy, and credibility of the knowledge produced. We suggest the paper may be of use to researchers and partners seeking to engage in principled and actionable research related to environmental change including impacts of past development.

Arctic Science, Ahead of Print. <br/> The expanding area of glacier forelands provides new terrain for ecosystem development. Plant succession facilitates this development, but this process remains poorly documented in marginal environments such as the High Arctic. This paper presents the results of the first repeat study of glacier foreland chronosequences conducted in the Canadian High Arctic. The forelands of Twin Glacier, Beitstad Glacier, and Teardrop Glacier near Alexandra Fiord, Ellesmere Island, Nunavut were first surveyed in 1995, and these surveys were repeated 21 years later using the same methods. The objectives of this study were to document the patterns of vascular plant species composition and abundance across these three forelands to (1) determine the accuracy of the hypothesis from the original study that succession on these forelands was directional, and (2) investigate the use of the chronosequence method in High Arctic succession studies. Forelands were surveyed using % cover estimates or presence/absence counts. Indicator species analysis and rates of change were used to quantify shifts in vascular plant species over time. Total plant cover increased by 2.4% in the first 100 m of the Twin Glacier foreland study area, and species richness also increased on younger terrain. Rates of peak cover and first appearance advance varied greatly between species and forelands, but were generally faster for graminoid and forb species than shrub species, and slower on species-poor Beitstad Glacier foreland. At all three forelands there was a general pattern of directional succession as all species advanced towards the retreating glacier margin. This supports the original hypothesis that directional succession is a common pattern for glacier forelands in the High Arctic. However, we also found that species-specific patterns and rates of change acted to create assemblages that differed between 1995 and 2016. Different abundances of species and successional trajectories were observed between the three forelands, pointing to the importance of local species pools and dispersal limitation. Finally, we observed that the first occurrence of most species was further from the glacier margin in 2016 compared to 1995, perhaps due to accelerating rates of glacier retreat. These species-specific patterns, differences between forelands, and the delayed response of vegetation to glacier retreat demonstrate the importance of using repeat studies over time and replication over space to confirm the results observed in High Arctic glacier foreland chronosequence studies.

Arctic Science, Ahead of Print. <br/> Thinning sea ice cover and earlier melt in the Arctic impact primary producer (PP) phenology, causing earlier ice algal bloom termination and phytoplankton bloom commencement. However, logistic constraints limit capturing the complete seasonal evolution of PPs and their physical drivers. Here, we combine spectral irradiance data from subsurface oceanographic moorings with synthetic aperture radar backscatter and meteorological variables to study light in Dease Strait, investigating its relation to timing and magnitude of surface PPs for 2017 and 2019. Ice algal blooms in 2017 and 2019 lasted 66 and 84 days, respectively, peaking within 2 days of snow melt onset. In 2019, lower temperatures and a deeper snowpack before snow melt extended the ice algal bloom. Melt pond formation increased light transmission, enabling a short, 6–7-day under-ice phytoplankton bloom in both years that was likely nutrient-limited. The 2019 phytoplankton bloom was less productive, possibly due to the longer ice algal bloom depleting surface nutrients. After ice break-up in 2019, a 31-day late-summer bloom occurred via wind-driven mixing. Our findings suggest that the combined remote sensing technique has novel applicability in other settings, providing insights into the changing state of PP phenology, and the need for long-term Arctic observations to discern regional climate change effects.

Arctic Science, Ahead of Print. <br/> Permafrost landscapes are becoming increasingly susceptible to widespread thaw due to climate change. Collating historical and ongoing data are critical for assessing permafrost conditions and spatiotemporal changes. Electrical resistivity tomography (ERT) is a geophysical technique that has become standard practice for characterizing permafrost. However, resistivity data—particularly raw measurements—often go unpublished and unshared, resulting in missed opportunities for knowledge exchange and collaboration. To fill this gap, we created the Canadian Permafrost Electrical Resistivity Survey database and established clear guidelines for data archival and reuse. Here, we present the first release of the database, which currently houses 280 ERT datasets, including standardized metadata, collected between 2008 and 2022 in British Columbia, Labrador, Northwest Territories, Québec, Yukon, and Alaska. These data present unique opportunities to better understand spatial and temporal variability of permafrost conditions across North America.