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1. Increasing detections of killer whales ( Orcinus orca ), in the Pacific Arctic: NOTES

   https://doi.org/10.1111/MMS.12551  

   Stafford, Kathleen M. (January 2018, Marine Mammal Science)
2. Evidence for massive and recurrent toxic blooms of Alexandrium catenella in the Alaskan Arctic

   https://doi.org/10.1073/pnas.2107387118  

   Anderson, Donald M.; Fachon, Evangeline; Pickart, Robert S.; Lin, Peigen; Fischer, Alexis D.; Richlen, Mindy L.; Uva, Victoria; Brosnahan, Michael L.; McRaven, Leah; Bahr, Frank; et al (October 2021, Proceedings of the National Academy of Sciences)

   Among the organisms that spread into and flourish in Arctic waters with rising temperatures and sea ice loss are toxic algae, a group of harmful algal bloom species that produce potent biotoxins. Alexandrium catenella , a cyst-forming dinoflagellate that causes paralytic shellfish poisoning worldwide, has been a significant threat to human health in southeastern Alaska for centuries. It is known to be transported into Arctic regions in waters transiting northward through the Bering Strait, yet there is little recognition of this organism as a human health concern north of the Strait. Here, we describe an exceptionally large A. catenella benthic cyst bed and hydrographic conditions across the Chukchi Sea that support germination and development of recurrent, locally originating and self-seeding blooms. Two prominent cyst accumulation zones result from deposition promoted by weak circulation. Cyst concentrations are among the highest reported globally for this species, and the cyst bed is at least 6× larger in area than any other. These extraordinary accumulations are attributed to repeated inputs from advected southern blooms and to localized cyst formation and deposition. Over the past two decades, warming has likely increased the magnitude of the germination flux twofold and advanced the timing of cell inoculation into the euphotic zone by 20 d. Conditions are also now favorable for bloom development in surface waters. The region is poised to support annually recurrent A. catenella blooms that are massive in scale, posing a significant and worrisome threat to public and ecosystem health in Alaskan Arctic communities where economies are subsistence based. 

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3. Essential oil content of Rhododendron tomentosum responds strongly to manipulation of ecosystem resources in Arctic Alaska

   https://doi.org/10.1139/as-2020-0055  

   Baldwin, Tracey A.; Oberbauer, Steven F. (September 2022, Arctic Science)

   The essential oils of the widely distributed boreal/Arctic dwarf shrub, Rhododendron tomentosum ssp. subarcticum (Harmaja) G.D. Wallace, have important ecological, cultural, medicinal, and commercial roles. To understand the relationship between resource limitation and essential oil content of this species we measured the amount and diversity of terpenes from shoots of plants exposed to a 14-year ecosystem resource manipulation experiment in Arctic Alaska. Treatments tested interactive effects of nitrogen (N) and phosphorus (P) addition, warming and N + P fertilization, and shading and N + P fertilization. The controls and NP fertilization had the highest essential oil content, whereas shading and P addition had less than 20% of the control content. Warming reduced essential oil content to <65% of that of the controls. Essential oil components varied greatly among the treatments, with significant differences in the expression of specific essential oil components. Large changes in plant community composition and ecosystem structure in response to treatments likely played a large role in the response of R. tomentosum. Our data suggest that resource changes in response to climate warming and its secondary effects on light and nutrient availability have the potential to change the profiles of essential oils in R. tomentosum, with important ecological and cultural impacts. 

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4. Genome analysis reveals diverse novel psychrotolerant Mucilaginibacter species in Arctic tundra soils

   https://doi.org/10.1093/ismeco/ycaf071  

   Kumar, Anil; Männistö, Minna K; Pätsi, Marika; Kerkhof, Lee J; Häggblom, Max M (January 2025, ISME Communications)

   As Arctic soil ecosystems warm due to climate change, enhanced microbial activity is projected to increase the rate of soil organic matter degradation. Delineating the diversity and activity of Arctic tundra microbial communities active in decomposition is thus of keen interest. Here, we describe novel cold-adapted bacteria in the genus Mucilaginibacter (Bacteroidota) isolated from Artic tundra soils in Finland. These isolates are aerobic chemoorganotrophs and appear well adapted to the low-temperature environment, where they are also exposed to desiccation and a wide regime of annual temperature variation. Initial 16S ribosomal RNA (rRNA)-based phylogenetic analysis suggested that five isolated strains represent new species of the genus Mucilaginibacter, confirmed by whole genome-based phylogenomic and average nucleotide identity. Five novel species are described: Mucilaginibacter geliditolerans sp. nov., Mucilaginibacter tundrae sp. nov., Mucilaginibacter empetricola sp. nov., Mucilaginibacter saanensis sp. nov., and Mucilaginibacter cryoferens sp. nov. Genome and phenotype analysis showed their potential in complex carbon degradation, nitrogen assimilation, polyphenol degradation, and adaptation to their tundra heath habitat. A pangenome analysis of the newly identified species alongside known members of the Mucilaginibacter genus sourced from various environments revealed the distinctive characteristics of the tundra strains. These strains possess unique genes related to energy production, nitrogen uptake, adaptation, and the synthesis of secondary metabolites that aid in their growth, potentially accounting for their prevalence in tundra soil. By uncovering novel species and strains within the Mucilaginibacter, we enhance our understanding of this genus and elucidate how environmental fluctuations shape the microbial functionality and interactions in Arctic tundra ecosystems. 

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5. Aufeis fields as novel groundwater‐dependent ecosystems in the arctic cryosphere

   https://doi.org/10.1002/lno.11626  

   Huryn, Alexander D.; Gooseff, Michael N.; Hendrickson, Patrick J.; Briggs, Martin A.; Tape, Ken D.; Terry, Neil C. (January 2021, Limnology and Oceanography)

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