Polar Research https://polarresearch.net/index.php/polar <p><em>Polar Research</em> is the international, peer-reviewed journal of the Norwegian Polar Institute. The scope of&nbsp;<em>Polar Research</em>&nbsp;encompasses research in all scientific disciplines relevant to the polar regions. These include, but are not limited to, the subfields of biology, ecology, geology, oceanography, glaciology and atmospheric science. Submissions from the social sciences and those focusing on polar management and policy issues are welcome. Contributions about Antarctica are particularly encouraged.</p> Norwegian Polar Institute en-US Polar Research 1751-8369 <p><span style="color: #4b7d92;">Authors contributing to Polar Research retain copyright of their work, with first publication rights granted to the Norwegian Polar Institute. Read the journal's full <a href="https://polarresearch.net/index.php/polar/openaccess">Copyright- and Licensing Policy</a>.</span></p> <p>&nbsp;</p> <p>&nbsp;</p> Diversity and distribution of heterotrophic flagellates in seawater of the Powell Basin, Antarctic Peninsula https://polarresearch.net/index.php/polar/article/view/5389 <p>Heterotrophic flagellates are essential components of the marine microbial food web. However, how the changes in flagellate populations reflect environmental changes in marine ecosystems is still unclear, especially in polar regions. In this study, we used pyrosequencing to examine the community structure of heterotrophic flagellates (HFs) in the Powell Basin’s surface waters of the northern Antarctic Peninsula. OTUs (operational taxonomic units) of different taxa and the correlations between community structure and environmental factors were analysed. Eight taxa of HFs were selected for the principal analysis: Telonemia, Picozoa, Rhizaria, Amoebozoa,&nbsp;<em>Apusomonas</em>, Centrohelida, Choanomonada and marine stramenopiles (MASTs). The HFs were defined as heterotrophic picoflagellates (HPFs; &lt;3 μm) and heterotrophic nanoflagellates (HNFs; &gt;3 μm, &lt;20 μm), which had similar dominant phyla (MASTs and Telonemia). However, their taxonomic composition differed. Environmental factors exerted similar effects on the community structure of both HPFs and HNPs. Compared with the correlation between HPF and environmental factors, the correlation between HNF and environmental factors was stronger. Salinity, bacterial biomass and the biological interactions amongst dominant taxa were the main variables to influence the diversity and community structure of HFs.</p> Zhiyi Chen Jianfeng He Shunan Cao Zhibo Lu Musheng Lan Hongyuan Zheng Guangfu Luo Fang Zhang Copyright (c) 2021 Zhiyi Chen, Jianfeng He, Shunan Cao, Zhibo Lu, Musheng Lan, Hongyuan Zheng, Guangfu Luo, Fang Zhang https://creativecommons.org/licenses/by-nd/4.0 2021-11-11 2021-11-11 40 10.33265/polar.v40.5389 Wildfires in the Campanian of James Ross Island: a new macro-charcoal record for the Antarctic Peninsula https://polarresearch.net/index.php/polar/article/view/5487 <p>The Cretaceous “high-fire” period was a global event that reached almost all continental masses during that period in Earth’s history. The extensive wildfires directly affected plant communities. Significant palaeobotanical records in the Antarctic Peninsula have been studied from the James Ross Sub-Basin, especially from the Santa Marta Formation. However, there is no described evidence for palaeo-wildfires in the area so far. Here, we present the first occurrence of fossilized macro-charcoal coming from James Ross Island, confirming that palaeo-wildfires occurred in the Campanian vegetation preserved in the Santa Marta Formation. The new charcoal material has a gymnospermous taxonomic affinity, more specifically with the Araucariaceae, which is in accordance with previous palaeobotanical records from James Ross Island. This occurrence adds new information to the construction of the palaeo-wildfire scenario for Gondwana.</p> Flaviana Jorge de Lima Juliana Manso Sayão Luiza C. M. de Oliveira Ponciano Luiz C. Weinschütz Rodrigo G. Figueiredo Taissa Marques Rodrigues Renan Alfredo Machado Bantim Antonio Álamo Feitosa Saraiva André Jasper Dieter Uhl Alexander W.A. Kellner Copyright (c) 2021 Flaviana Jorge de Lima, Juliana Manso Sayão, Luiza C. M. de Oliveira Ponciano, Luiz C. Weinschütz, Rodrigo Giesta Figueiredo, Taissa Marques Rodrigues, Renan Alfredo Machado Bantim, Antonio Álamo Feitosa Saraiva, André Jasper, Dieter Uhl, Alexander Wilhelm Armin Kellner https://creativecommons.org/licenses/by-nd/4.0 2021-10-20 2021-10-20 40 10.33265/polar.v40.5487 The Billefjorden Fault Zone north of Spitsbergen: a major terrane boundary? https://polarresearch.net/index.php/polar/article/view/7668 <p>The Billefjorden Fault Zone is a major terrane boundary in the Norwegian Arctic. The fault separates basement rocks of Svalbard’s north-eastern and north-western terranes that recorded discrete Precambrian tectonothermal histories and were accreted, intensely deformed and metamorphosed during the Caledonian Orogeny. Although the fault represents a major, crustal-scale tectonic boundary, its northward extent is not well constrained. The present short contribution addresses this issue and presents new seismic mapping of structures and rock units north of Wijdefjorden, where the Billefjorden Fault Zone may continue. This study shows that there is no evidence for major faulting of the top-basement reflection, and therefore, that the Billefjorden Fault Zone may die out within Wijdefjorden–Austfjorden, step ≥ 20 km laterally, or be invisible on the presented seismic data. Seismic data also suggest that Caledonian basement rocks in Ny-Friesland (north-eastern terrane) are not significantly different from basement rocks below the Devonian Graben in Andrée Land (north-western terrane). Potential implications include the absence of a major terrane boundary in northern Spitsbergen.</p> Jean-Baptiste Koehl Lis Allaart Copyright (c) 2021 Jean-Baptiste Koehl, Lis Allaart https://creativecommons.org/licenses/by-nd/4.0 2021-10-13 2021-10-13 40 10.33265/polar.v40.7668 Variation in body size of ringed seals (<em>Pusa hispida hispida</em>) across the circumpolar Arctic: evidence of morphs, ecotypes or simply extreme plasticity? https://polarresearch.net/index.php/polar/article/view/5753 <p>The ringed seal is a small phocid seal that has a northern circumpolar distribution. It has long been recognized that body size is variable in ringed seals, and it has been suggested that ecotypes that differ in size exist. This study explores patterns of body size (length and girth) and age-at-maturity across most of the Arctic subspecies’ range using morphometric data from 35 sites. Asymptotic lengths varied from 113 to 151 cm, with sites falling into five distinct size clusters (for each sex). Age-at-maturity ranged from 3.1 to 7.4 years, with sites that had early ages of sexual maturity generally having small length-at-maturity and small final body length. The sexes differed in length at some sites, but not in a consistent pattern of dimorphism. The largest ringed seals occurred in western Greenland and eastern Canada, and the smallest occurred in Alaska and the White Sea. Latitudinal trends occurred only within sites in the eastern Canadian Arctic. Girth (with length and season accounted for) was also highly variable but showed no notable spatial pattern; males tended to be more rotund than females. Genetic studies are needed, starting with the “giants” at Kangia (Greenland) and in northern Canada to determine whether they are genetically distinct ecotypes. Additional research is also needed to understand the ecological linkages that drive the significant regional size differences in ringed seals that were confirmed in this study, and also to understand their implications with respect to potential adaptation to climate change.</p> Kit M. Kovacs John Citta Tanya Brown Rune Dietz Steve Ferguson Lois Harwood Magali Houde Ellen V. Lea Lori Quakenbush Frank Riget Aqqalu Rosing-Asvid Tom Smith Vladimir Svetochev Olga Svetocheva Christian Lydersen Copyright (c) 2021 Kit M. Kovacs, John Citta, Tanya Brown, Rune Dietz, Steve Ferguson, Lois Harwood, Magali Houde, Ellen V. Lea, Lori Quakenbush, Frank Riget, Aqqalu Rosing-Asvid, Tom Smith, Vladimir Svetochev, Olga Svetocheva, Christian Lydersen https://creativecommons.org/licenses/by-nd/4.0 2021-09-30 2021-09-30 40 10.33265/polar.v40.5753 Warming of Atlantic Water in three west Spitsbergen fjords: recent patterns and century-long trends https://polarresearch.net/index.php/polar/article/view/5392 <p>We investigated the recent warming of summer Atlantic Water in relation to the century-long trends in maximum temperature in three west Spitsbergen fjords: Isfjorden, Grønfjorden and Billefjorden. On the basis of repeated along-fjord transects in late summer 2003–2019, we found that the warming has been pronounced not only in the outer but also in the inner domain of Isfjorden, where the presence of waters of Atlantic origin was registered more frequently after 2011 compared to early 2000s. Furthermore, Atlantic waters occurred more frequently in the bottom layers in the inner part of the fjord. In all the investigated fjords, the year 2014 was the warmest and saltiest during the period 2003–2019, which is consistent with previous reports for other west Spitsbergen fjords. In 2014, the mean temperature and salinity in Isfjorden and Grønfjorden exceeded 4.9 °C and 34.7 (in Billefjorden, 4.0 °C and 34.67, respectively). With the new data for 2010–19, we extended the time-series of maximum Atlantic Water temperature in Isfjorden and Grønfjorden, covering 1912–2009, reported previously by Pavlov et al. 2013. For the period 1912–2019, the average long-term trend of Atlantic Water maximum temperature is 0.25 °C/decade and 0.22 °C/decade in the outer part of Isfjorden and Grønfjorden, respectively. In the first two decades of the 21st century, the warming trend is steeper compared to the 20th century, 0.78 °C/decade in Isfjorden and 0.56 °C/decade in Grønfjorden, highlighting the strength of the ongoing ‘Atlantification’ of west Spitsbergen fjords.</p> Ekaterina V. Bloshkina Alexey K. Pavlov Kirill Filchuk Copyright (c) 2021 Ekaterina V. Bloshkina, Alexey K. Pavlov, Kirill Filchuk https://creativecommons.org/licenses/by-nd/4.0 2021-09-09 2021-09-09 40 10.33265/polar.v40.5392 Liverworts frequently form mycothalli on Spitsbergen in the High Arctic https://polarresearch.net/index.php/polar/article/view/7727 <p>Mycothalli, symbioses between liverworts and soil fungi, have not previously been recorded in the Arctic. Here, 13 species of leafy liverwort from west Spitsbergen in the High Arctic are examined for the symbiosis using epifluorescence microscopy and sequencing of fungal ribosomal (<em>r</em>)RNA genes amplified from plant tissues. Microscopy showed that intracellular hyphal coils, key indicators of the symbiosis, were frequent (&gt;40% stem length colonized) in nine species of liverwort in the families Anastrophyllaceae, Lophoziaceae, Cephaloziellaceae, Cephaloziaceae and Scapaniaceae, with hyphae occurring frequently (&gt;40% cells occupied) in the rhizoids of 10 species in the same families. Dark septate hyphae, apparently formed by ascomycetes, were frequent on the stems of members of the Anastrophyllaceae, Cephaloziellaceae and Cephaloziaceae, and typically those growing on acidic mine tailings. Sequencing of fungal&nbsp;<em>r</em>RNA genes showed the presence of nine distinct groups (based on a 3% cut-off for ITS sequence divergence) of the basidiomycete&nbsp;<em>Serendipita</em>&nbsp;in the Anastrophyllaceae and Lophoziaceae, with ordinations and correlative analyses showing the presence of the genus to be positively associated with the frequency of hyphal coils, the occurrence of which was positively associated with edaphic factors (soil&nbsp;<em>δ</em><sup>15</sup>N value and concentrations of moisture, nitrogen, carbon and organic matter). We propose that the frequency of mycothalli in leafy liverworts on west Spitsbergen, which is an order of magnitude higher than at lower latitudes, may arise from benefits conferred by mycobionts on their hosts in the harsh environment of the High Arctic.</p> Kevin K. Newsham William P. Goodall-Copestake Copyright (c) 2021 Kevin K. Newsham, William P. Goodall-Copestake https://creativecommons.org/licenses/by-nd/4.0 2021-09-08 2021-09-08 40 10.33265/polar.v40.7727 Historic temperature observations on Nordaustlandet, north-east Svalbard https://polarresearch.net/index.php/polar/article/view/7564 <p>Long-term meteorological data for the Arctic are sparse. One of the longest quasi-continuous temperature time series in the High Arctic is the extended Svalbard Airport series, providing daily temperature data from 1898 until the present. Here, I derive an adjustment to historic temperature observations on the island of Nordaustlandet, north-east Svalbard, in order to link these to the extended Svalbard Airport series. This includes the Haudegen observations at Rijpfjorden during 1944/45 and a previously unrecognized data set obtained by the Norwegian hunters and trappers Gunnar Knoph and Henry Rudi during their wintering at Rijpfjorden in 1934/35. The adjustment is based on data from an automatic weather station at Rijpfjorden during 2014–16 and verified with other independent historic temperature observations on Nordaustlandet. An analysis of the Haudegen radiosonde data indicates that the surface temperature observations at Rijpfjorden are generally well correlated with the free tropospheric temperatures at 850 hPa, but occasionally show the occurrence of boundary-layer inversions during winter, where local temperatures fall substantially below what is expected from the regression. The adjusted historic observations from Nordaustlandet can, therefore, be used to fill remaining gaps in the extended Svalbard Airport series.</p> Björn-Martin Sinnhuber Copyright (c) 2021 Björn-Martin Sinnhuber https://creativecommons.org/licenses/by-nd/4.0 2021-07-20 2021-07-20 40 10.33265/polar.v40.7564 Stability of space use in Svalbard coastal female polar bears: intra-individual variability and influence of kinship https://polarresearch.net/index.php/polar/article/view/5355 <p>Philopatry influences animal distribution and can lead to a kinship-based spatial structure, where proximity and relatedness are tightly linked. In the Barents Sea region, polar bears (<em>Ursus maritimus</em>) of the coastal ecotype remain year-round within the Svalbard archipelago. This coastal strategy is thought to be stable across years; however, little is known about the intra-individual variability in site fidelity or the influence of kinship on space use. Using high-resolution GPS telemetry, we looked at multi-year philopatry among 17 coastal female polar bears over eight years (2011–19) and investigated whether it is linked to the females’ degree of kinship. Individuals showed a stable space use in both consecutive and non-consecutive years. Yearly individual home ranges (HRs) overlapped, on average, by 44% (range: 9–96%), and their centroids were, on average, 15 km (range: 2–63 km) apart. The space use of related females revealed a year-round strong female kin structure. Annual HRs of related females overlapped, on average, by 24% (range: 0–66%), and their centroids were, on average, 18 km (range: 2–52 km) apart. In contrast, non-related females had much larger distances between centroids (average: 160 km, range: 59–283 km). Additionally, females showed a great site fidelity in all seasons: individual seasonal HR centroids were, on average, less than 30 km (range: 1.8–172 km) apart. Bears in this region seem to exhibit a stronger site fidelity than those reported from other parts of the species range. These findings also highlight the importance of maternal learning in space use.</p> Clément Brun Marie-Anne Blanchet Rolf A. Ims Jon Aars Copyright (c) 2021 Clément Brun, Marie-Anne Blanchet, Rolf A. Ims, Jon Aars https://creativecommons.org/licenses/by-nd/4.0 2021-05-28 2021-05-28 40 10.33265/polar.v40.5355 Stable ringed seal (<em>Pusa hispida</em>) demography despite significant habitat change in Svalbard, Norway https://polarresearch.net/index.php/polar/article/view/5391 <p>Ringed seals, which are small phocid seals, range across the circumpolar Arctic, and have evolved in close association with sea ice and depend on it for all aspects of their life history. This research study compares age structure, reproductive parameters, body size and condition during three time periods—1981–82 (<em>n</em>&nbsp;= 277), 2002–04 (<em>n</em>&nbsp;= 272) and 2012–18 (<em>n</em>&nbsp;= 212)—to study potential changes in demography in ringed seals in western Svalbard, Norway, an area that has undergone dramatic changes in sea-ice conditions during recent decades. Age distributions for the three time periods were similar, with the exception that the most recent period had a higher proportion of young animals. Age at sexual maturity for both sexes was similar for the two most recent periods, both being lower than in the 1980s. Ovulation rates did not vary significantly among the three periods (range 0.86–0.94). Pregnancy rates were only available for the most recent study period (0.71); this value falls within the range reported from other Arctic regions. Body length showed no clear temporal patterns; males were slightly longer in the most recent period, while females were slightly longer in the first period. Data from May in all periods suggest that body condition has not varied significantly through time. In conclusion, although the ringed seal breeding habitat in Svalbard has declined significantly in recent decades, demographic parameters appear to be largely unaffected. Life-history plasticity in combination with a small-scale regional variation in environmental conditions might explain the lack of changes in demography over time.</p> Magnus Andersen Kit M. Kovacs Christian Lydersen Copyright (c) 2021 Magnus Andersen, Kit M. Kovacs, Christian Lydersen https://creativecommons.org/licenses/by-nd/4.0 2021-04-30 2021-04-30 40 10.33265/polar.v40.5391 Species diversity of macroalgae in Grønfjorden, Spitsbergen, Svalbard https://polarresearch.net/index.php/polar/article/view/3682 <p>Climate changes in the North Atlantic and Arctic affect the macrophytobenthos along with other components of the ecosystem, resulting in an increase of species diversity and biomass in western Spitsbergen, as has been reported. Grønfjorden is located at the mouth of one of the largest fjords of Spitsbergen, Isfjorden, and is influenced by the recent significant increase in the inflow of Atlantic Water. However, there are nearly no published data on the phytobenthic communities in this area. This research study of the littoral and sublittoral areas of Grønfjorden in 2013–14 documented 68 species, mostly high-boreal and boreal–Arctic species. When compared with species diversity in the other areas of western Spitsbergen, the data show the uniqueness of Grønfjorden’s species composition.</p> Svetlana Malavenda Copyright (c) 2021 Svetlana Malavenda https://creativecommons.org/licenses/by-nd/4.0 2021-04-27 2021-04-27 40 10.33265/polar.v40.3682 A climatology of wintertime low-level jets in Nares Strait https://polarresearch.net/index.php/polar/article/view/3622 <p>Intense, southward low-level winds are common in Nares Strait, between Ellesmere Island and northern Greenland. The steep topography along Nares Strait leads to channelling effects, resulting in an along-strait flow. This research study presents a 30-year climatology of the flow regime from simulations of the COSMO-CLM climate model. The simulations are available for the winter periods (November–April) 1987/88 to 2016/17, and thus, cover a period long enough to give robust long-term characteristics of Nares Strait. The horizontal resolution of 15 km is high enough to represent the complex terrain and the meteorological conditions realistically. The 30-year climatology shows that LLJs associated with gap flows are a climatological feature of Nares Strait. The maximum of the mean 10-m wind speed is around 12 m s<sup>-1</sup>&nbsp;and is located at the southern exit of Smith Sound. The wind speed is strongly related to the pressure gradient. Single events reach wind speeds of 40 m s<sup>-1</sup>&nbsp;in the daily mean. The LLJs are associated with gap flows within the narrowest parts of the strait under stably stratified conditions, with the main LLJ occurring at 100–250 m height. With increasing mountain Froude number, the LLJ wind speed and height increase. The frequency of strong wind events (&gt;20 m s<sup>-1</sup>&nbsp;in the daily mean) for the 10 m wind shows a strong interannual variability with an average of 15 events per winter. Channelled winds have a strong impact on the formation of the North Water polynya.</p> Svenja H.E. Kohnemann Günther Heinemann Copyright (c) 2021 Svenja H.E. Kohnemann, Günther Heinemann https://creativecommons.org/licenses/by-nd/4.0 2021-04-19 2021-04-19 40 10.33265/polar.v40.3622 Sudden death of an Arctic wolf population in Greenland https://polarresearch.net/index.php/polar/article/view/5493 <p>This study reports the disappearance of a small Arctic wolf population in north-east Greenland founded in 1979 and provides the first long-term information on the wolf packs of this region. Data sources comprised specialized wolf surveys in two of three distributional core areas during three summers, 2012–14, and incidental sightings of wolves by military ground patrols during winter and by others year-round. The resulting time series spans 40 years (1979–2018). After gradually increasing for 14 years, the sighting rate peaked in 1996 and then declined to zero after May 2002, suggesting that the population went extinct. The crash occurred despite year-round legal protection in a national park and resulted in a 51.2% reduction in the extent of the occupied wolf range in Greenland and a 41.8% reduction in Greenland’s wolf population size. It was outside the scope of this study to conduct a complete analysis of all potential factors in the disappearance. In north Greenland, a small population of up to 32 wolves during optimal years continues to exist, and dispersers reach north-east Greenland occasionally. A number of measures are proposed that, if implemented by the Greenland Home Rule Government, would help secure the future of the few remaining wolves on the island.</p> Ulf Marquard-Petersen Copyright (c) 2021 Ulf Marquard-Petersen https://creativecommons.org/licenses/by-nd/4.0 2021-03-31 2021-03-31 40 10.33265/polar.v40.5493 Inferring population structure and genetic diversity of the invasive alien Nootka lupin in Iceland https://polarresearch.net/index.php/polar/article/view/4536 <p>Polar and subpolar regions are known for their particular vulnerability and sensitivity to the detrimental effects of non-indigenous species, which is well exemplified by the Nootka lupin (<em>Lupinus nootkatensis</em>) spread in Iceland. Since understanding the population and ecological genetics of invasive alien species offers hope for counteracting harmful biological invasions, the objective of the present study was to investigate interspecific variation in&nbsp;<em>L. nootkatensis</em>&nbsp;in Iceland in relation to a native population in Alaska. Moreover, we aimed to assess whether internal transcribed spacer 2 (ITS2) has sufficient phylogenetic applicability for a large-scale screening of the genetic diversity of a non-indigenous population of this species. This study, which is the first attempt to investigate the genetic diversity of the Nootka lupin in Iceland, included plant samples from eight locations in Iceland and one in Alaska. The analyses included genotyping by sequencing of the 417-nucleotide fragment of the 5.8S ribosomal RNA, ITS2 and part of the large subunit ribosomal RNA (GenBank MT026578-MT026580, MT077004). The main findings showed the presence of five previously unexplained single-nucleotide polymorphisms (SNPs); however, their discriminatory power for Icelandic populations was relatively low, since polymorphism information content (PIC) values ranged from 0.0182 to 0.0526, with average heterozygosity 0.0296. Concomitantly, analysis of multilocus genotypes (MLG) revealed sufficient differences in MLGs variants and their frequency to form genotypic patterns unique for Alaskan and Icelandic populations, revealing an internal genetic structure of the studied group. The proposed SNP panel needs to be supplemented with other nuclear and organellar markers.</p> Jakub Skorupski Magdalena Szenejko Martyna Gruba-Tabaka Przemysław Śmietana Remigiusz Panicz Copyright (c) 2021 Jakub Skorupski, Magdalena Szenejko, Martyna Gruba-Tabaka, Przemysław Śmietana, Remigiusz Panicz https://creativecommons.org/licenses/by-nd/4.0 2021-02-17 2021-02-17 40 10.33265/polar.v40.4536 Distribution and habitat characteristics of pinnipeds and polar bears in the Svalbard Archipelago, 2005–2018 https://polarresearch.net/index.php/polar/article/view/5326 <p>This study presents comprehensive mapping of the current distribution of pinnipeds and polar bears (<em>Ursus maritimus</em>) around Svalbard based on a regional marine mammal sightings programme and explores time-trends (2005–2018). Walruses (<em>Odobenus rosmarus</em>) were observed with high frequency and in high numbers around previously identified haul-out sites. At-sea walruses were seen close to the coast in shallow waters. Ringed seals (<em>Pusa hispida</em>) were observed in coastal areas throughout Svalbard, often in association with tidewater glacier fronts. There was no increase in the mean latitude for ringed seal observations, but there was an increased frequency of observations at around 82°N, which reflects their following a northward shift in the ice edge during summer foraging trips. Bearded seals (<em>Erignathus barbatus</em>) were observed frequently in north-western Spitsbergen and shared many habitat features with ringed seals. There was a slight increase in the mean latitude of bearded seal observations and a decreased frequency of observation in the southern parts of the archipelago, suggesting that this species might be shifting its distribution. Harbour seal (<em>Phoca vitulina</em>) observations within fjords have increased, likely as a consequence of increased inflow of Atlantic water into west coast fjords. Harp seals (<em>Pagophilus groenlandicus</em>) were observed with high frequency north of Svalbard. Hooded seals (<em>Cystophora cristata</em>) were observed only rarely. Polar bears were reported most frequently, undoubtedly as a result of an effort bias favouring this species. In spite of biases, citizen-based observations are useful for assessing broad distributional patterns of marine mammals through time.</p> Olof Bengtsson Charmain D. Hamilton Christian Lydersen Magnus Andersen Kit M. Kovacs Copyright (c) 2021 Olof Bengtsson, Charmain D. Hamilton, Christian Lydersen, Magnus Andersen, Kit M. Kovacs https://creativecommons.org/licenses/by-nd/4.0 2021-02-04 2021-02-04 40 10.33265/polar.v40.5326 Subglacial discharge weakens the stability of the Ross Ice Shelf around the grounding line https://polarresearch.net/index.php/polar/article/view/3377 <p>In this paper, we examine potential impact of discharge in Subglacial Lake Engelhardt, West Antarctica, on the stability of the Ross Ice Shelf around the grounding line by combining satellite altimetry and remote sensing images. According to satellite altimetry data from the Ice, Cloud and Land Elevation Satellite (ICESat; 2003–06), Subglacial Lake Engelhardt (SLE) discharged ca. 1.91 ± 0.04 km<sup>3</sup>&nbsp;of water into the downstream region. The ice-surface record derived from ICESat (2006–09) and CryoSat-2 (2011–17) data shows that the lake gained ca. 2.09 ± 0.05 km<sup>3</sup>&nbsp;of water during the refilling event following the drainage event, taking three times as much time to reach the previous water level before the discharge; the calculation demonstrates that water input from an upstream lake is unable to sustain water increase in SLE, indicating that the subglacial, hydrologic system and groundwater flow could have contributed to water increase in SLE via hydrologic networks. Satellite images captured surface depressions and crevasses at the drainage outlet point of hydrologic networks around the grounding line; satellite altimetry data show that the ice surface there is still depressing even though the subglacial discharge has finished, potentially reflecting the long-term impact of subglacial discharge on the stability of the immediate Ross Ice Shelf around the grounding line.</p> Yan Li Hongling Shi Yang Lu Zizhan Zhang Hui Xi Copyright (c) 2021 Yan Li, Hongling Shi, Yang Lu, Zizhan Zhang, Hui Xi https://creativecommons.org/licenses/by-nd/4.0 2021-01-22 2021-01-22 40 10.33265/polar.v40.3377 Organic carbon and microbiome in tundra and forest–tundra permafrost soils, southern Yamal, Russia https://polarresearch.net/index.php/polar/article/view/5283 <p>Permafrost soils differ significantly from other soils because they serve as a huge reservoir for organic carbon accumulated during the Quaternary Period, which is at risk of being released as the Arctic warms. This study aimed to characterize existing carbon pools, delineate possible mineralization risks of soil organic matter and assess microbial communities in the tundra and forest–tundra permafrost soils of the southern Yamal region of Russia. The profile distribution of carbon, nitrogen and the C:N ratio showed non-gradual changes with depth due to the manifestation of cryopedogenesis in soil profiles, which lead to cryogenic mass transfer. Mean carbon stocks for the study area were 7.85 ± 2.24 kg m<sup>−2</sup>&nbsp;(0–10 cm layer), 14.97 ± 5.53 kg m<sup>−2</sup>&nbsp;(0–30 cm) and 23.99 ± 8.00 kg m<sup>−2</sup>&nbsp;(0–100 cm). The analysis of the humus type revealed a predominance of fulvic type and low-molecular-weight fragments in the fulvic acid fraction, which indicates high mineralization risk of humic substances under Arctic warming conditions. The taxonomic analysis of soil microbiomes revealed 48 bacterial and archaeal phyla, among which proteobacteria (27%) and actinobacteria (20%) were predominant. The pH range and nitrogen accumulation were the main environmental determinants of microbial community diversity and composition in the studied soils.</p> Ivan Alekseev Aleksei Zverev Evgeny Abakumov Copyright (c) 2021 Ivan Alekseev, Aleksei Zverev, Evgeny Abakumov https://creativecommons.org/licenses/by-nd/4.0 2021-01-08 2021-01-08 40 10.33265/polar.v40.5283 Missing and misidentified museum specimens hinder long-term monitoring: a case study of shell-bearing gastropods from the Kola Meridian transect, Barents Sea https://polarresearch.net/index.php/polar/article/view/4999 <p>The consequences of global change cannot be estimated without long-term monitoring programmes. The Kola Meridian transect, along 33°30’E, in the Barents Sea is the longest term monitoring area in the Arctic. Regular (usually annual) hydrobiological benthic surveys along that transect have been performed since 1899. Materials stored in museum collections remain the main source of the faunistic information obtained during the surveys, while only a minor part of these data was published. We reexamined all samples of shell-bearing gastropods from the Kola Meridian stored at the Zoological Institute of the Russian Academy of Sciences and at Saint Petersburg State University. We found only 159 museum lots from 73 samples, which constitute a very small portion of the total material collected along the transect. Approximately one-third of them (54 lots) was misidentified or includes individuals that cannot be identified at species level. The species composition revealed by museum materials differs substantially from published checklists. Majority of the studied samples (40) were collected during 1899–1920. However, the extant collections do not provide a reliable baseline for the Kola Meridian. We propose that the storage of zoological material in public collections should be considered as an essential part of long-term monitoring programmes.</p> Ivan O. Nekhaev Alexey V. Merkuliev Copyright (c) 2021 Ivan O. Nekhaev, Alexey V. Merkuliev https://creativecommons.org/licenses/by-nd/4.0 2021-03-03 2021-03-03 40 10.33265/polar.v40.4999 Review of Anna across the Arctic, by Liz O’Connell & Arin Underwood, illustrated by Arin Underwood (2020). Anchorage, AK, USA: WonderVisions. 35 pp. ISBN: 978-0-9677126-6-6 https://polarresearch.net/index.php/polar/article/view/7980 Helle V. Goldman Copyright (c) 2021 Helle V. Goldman https://creativecommons.org/licenses/by-nd/4.0 2021-07-09 2021-07-09 40 10.33265/polar.v40.7980 Review of Goodbye, ice: Arctic poems, by Lawrence Millman (2020). Albuquerque, NM, USA: Coyote Arts. 83 pp. ISBN paper: 978-1-58775-031-1; e-book: 978-1-58775-032-8 https://polarresearch.net/index.php/polar/article/view/7836 E. Lewis Williams Copyright (c) 2021 E. Lewis Williams https://creativecommons.org/licenses/by-nd/4.0 2021-06-07 2021-06-07 40 10.33265/polar.v40.7836 Review of The life of permafrost—a history of frozen earth in Russian and Soviet science, by Pey-Yi Chu (2020). Toronto, Buffalo, and London: University of Toronto Press. 288 pp. ISBN-978-1-4875-0193-8. https://polarresearch.net/index.php/polar/article/view/7598 Peder Roberts Copyright (c) 2021 Peder Roberts https://creativecommons.org/licenses/by-nd/4.0 2021-03-22 2021-03-22 40 10.33265/polar.v40.7598