Filters: Language: English × Article Type: Research Article ×

Dieuwertje S. Wesselink,

Eirik Malnes,

Markus Eckerstorfer,

Roderik C. Lindenbergh

Polar Research, Journal Year: 2017, Volume and Issue: 36, P. 1 - 12

Published: June 30, 2017

Snow avalanches pose a threat to people and infrastructure in and around Svalbard’s main settlement Longyearbyen. Since January 2016, publically available regional avalanche warnings are issued daily for Nordenskiöld Land, the area around Longyearbyen. Avalanche warning services rely on information of when and where avalanches occur. Systematic field observations of avalanche activity are not feasible across all of the vast area (ca. 7200 km2) of Nordenskiöld Land. Svalbard also experiences over four months of polar night per year. However, using synthetic aperture radar (SAR), a weather- and light-independent technique, large areas can be monitored at once. We have developed a …

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Catherine L. Docherty,

Tenna Riis,

David M. Hannah,

Simon Rosenhøj Leth,

Alexander M. Milner

Polar Research, Journal Year: 2018, Volume and Issue: 37, P. 1 - 7

Published: March 19, 2018

Permafrost thaw induced by climate change will cause increased release of nutrients and organic matter from the active layer to Arctic streams and, with increased water temperature, will potentially enhance algal biomass and nutrient uptake. Although essential for accurately predicting the response of Arctic streams to environmental change, knowledge of nutrient release on current Arctic in-stream processing is limited. Addressing this research gap, we quantified nutrient uptake of short-term releases of NO 3− , PO 43- and NH 4+ during peak snowmelt season in five streams of contrasting physiochemical characteristics (from unstable, highly turbid to highly stable, clear-water systems) in …

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Jenny Maccali,

Claude Hillaire-Marcel,

Christelle Not

Polar Research, Journal Year: 2018, Volume and Issue: 37, P. 1 - 10

Published: March 22, 2018

Under modern conditions, sediments from the large continental shelves of the Arctic Ocean are mixed by currents, incorporated into sea ice and redistributed over the Arctic Basin through the Beaufort Gyre and Trans-Polar Drift major sea-ice routes. Here, compiling data from the literature and combining them with our own data, we explore how radiogenic isotopes (Sr, Pb and Nd) from Arctic shelf surface sediment can be used to identify inland and coastal sediment sources. Based on discriminant function analyses, the use of two-isotope systematics introduces a large uncertainty (ca. 50%) that prevents unequivocal identifications of regional shelf signatures. However, when …

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Luke Storrie,

Christian Lydersen,

Magnus Andersen,

Russell B. Wynn,

Kit M. Kovacs

Polar Research, Journal Year: 2018, Volume and Issue: 37, P. 1 - 12

Published: June 1, 2018

This study used 13 years of cetacean sighting data (2002–2014) from waters around the Svalbard Archipelago to determine key habitats for year-round resident species as well as seasonally resident species, and to explore spatial overlap between these groups via a combination of kernel density estimation and Maxent modelling. The data set consists of observations made by research vessels conducting various marine studies, coast guard ships and marine-cruise tourist operators. Data are reported from the seasonal period in which there is daylight (March-November), though 95% of the observations occurred June- September. Changes over the study period were investigated, within the limits …

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Luidmila A. Pestryakova,

Ulrike Herzschuh,

Ruslan Gorodnichev,

Sebastian Wetterich

Polar Research, Journal Year: 2018, Volume and Issue: 37, P. 1 - 12

Published: July 31, 2018

Relative abundances of 157 diatom taxa from Yakutian lake surface-sediments were investigated for their potential to indicate certain environmental conditions. Data from 206 sites from Arctic, sub-Arctic and boreal environments were included. Redundancy analyses were performed to assess the explanatory power of mean July temperature (T July ), conductivity, pH, dissolved silica concentration, phosphate concentration, lake depth and vegetation type on diatom species composition. Boosted regression tree analyses were performed to infer the most relevant environmental variables for abundances of individual taxa and weighted average regression was applied to infer their respective optimum and tolerance. Electrical conductivity was best indicated …

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Agnieszka Promińska,

Waldemar Walczowski,

Eva Falck

Polar Research, Journal Year: 2018, Volume and Issue: 37, P. 1 - 12

Published: Sept. 6, 2018

Progressing warming in the Arctic and increased extreme weather events can significantly influence the hydrography of Svalbard fjords, leading to changes towards more Atlantic-type waters in the fjords. In this paper, we look into the hydrographic conditions in Hornsund, the southernmost fjord on the west coast of Svalbard, by analysing high-resolution CTD measurements collected in July during cruises with the RV Oceania between 2001 and 2015. These observations revealed high interannual variability in temperature, salinity and distribution of water masses, mainly due to differences in timing of the transition between winter and summer conditions but also as a result of …

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Shunan Cao,

Jianfeng He,

Fang Zhang,

Ling Lin,

Yuan Gao,

Qiming Zhou

Polar Research, Journal Year: 2019, Volume and Issue: 38, P. 1 - 20

Published: March 21, 2019

Global climate change is significantly affecting marine life off the northern tip of the Antarctic Peninsula, but little is known about microbial ecology in this area. The main goal of this study was to investigate the bacterioplankton community structure in surface waters using pyrosequencing and to determine factors influencing this community. Pelagibacterales and Rhodobacterales (Alphaproteobacteria), Oceanospirillales and Alteromonadales (Gammaproteobacteria), and Flavobacteriales (Bacteroidetes) were the core taxa in our samples, and the five most relatively abundant genera were Pelagibacter, Polaribacter, Octadecabacter, group HTCC2207 and Sulfitobacter. Although nutrients and chlorophyll a (chl a) contributed more to bacterioplankton community structure than water masses …

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Karen Lone,

Jon Aars,

Christian Lydersen,

Kit M. Kovacs,

Charmain D. Hamilton

Polar Research, Journal Year: 2019, Volume and Issue: 38, P. 1 - 15

Published: Sept. 13, 2019

Ringed seals are a central component of the Arctic ecosystem; they have a circumpolar distribution and are both important predators of lower trophic animals (invertebrates and fishes) and prey for polar bears and coastal human populations. They depend on sea ice for reproduction, moulting and resting, and they consume significant amounts of ice-associated prey. The population of ringed seals in Svalbard, Norway, uses both coastal and offshore habitats, the latter being important during seasonal migrations undertaken by some animals, mostly juveniles. This study examined habitat preferences of 18 satellite-tracked ringed seals (mostly young animals, but also a few adults) during …

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Clémentine Peggy Anne-Marie Colpaert,

Boris Leonidovich Nikitenko

Polar Research, Journal Year: 2019, Volume and Issue: 38, P. 1 - 10

Published: March 5, 2019

This study presents a taxonomical review of the species Pseudolamarckina pseudorjasanensis Dain, 1967 collected at different sampling levels from the central and northern parts of European Russia and from Western Siberia. Morphological and biometrical analyses show that P. pseudorjasanensis is characterized by wide intraspecific variabilities and may encompass various previously described Kimmeridgian species of the genus Pseudolamarckina. The first appearance of P. pseudorjasanensis is recorded from the latest Early Kimmeridgian of sub-Mediterranean to Arctic regions. Furthermore, P. pseudorjasanensis appears to be the marker species of the foraminiferal JF41 Zone in Kimmeridgian sections of sub-boreal, boreal and Arctic regions. This JF41 …

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Michał Hubert Węgrzyn,

Beata Cykowska-Marzencka,

Monica Alterskjær Sundset,

Paulina Wietrzyk-Pełka,

Agnieszka Galanty

Polar Research, Journal Year: 2019, Volume and Issue: 38, P. 1 - 10

Published: Jan. 22, 2019

Previous studies of Eurasian tundra reindeer (Rangifer tarandus tarandus) in Norway indicate that their rumen microbiota play a key role in degrading lichen secondary metabolites. We investigated the presence of usnic acid and atranorin in faecal samples from Svalbard reindeer (R. tarandus platyrhynchus). Samples were collected in Bolterdalen valley together with vegetation samples from the study site. The mesic tundra in this area was dominated by vascular plants (59% of vegetation cover). Bryophytes (16%) and lichens (25%) were also present. Qualitative and quantitative analyses of usnic acid and atranorin in lichen and faeces samples were performed using high-performance liquid chromatography. …

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