The sensitivity of diatom taxa from Yakutian lakes (north-eastern Siberia) to electrical conductivity and other environmental variables

Luidmila A. Pestryakova,

Ulrike Herzschuh,

Ruslan Gorodnichev,

Sebastian Wetterich

Опубликована Июль 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 …

Determining the species assemblage and habitat use of cetaceans in the Svalbard Archipelago, based on observations from 2002 to 2014

Luke Storrie,

Christian Lydersen,

Magnus Andersen,

Russell B. Wynn,

Kit M. Kovacs

Опубликована Июнь 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 …

Radiogenic isotope (Nd, Pb, Sr) signatures of surface and sea ice-transported sediments from the Arctic Ocean under the present interglacial conditions

Jenny Maccali,

Claude Hillaire-Marcel,

Christelle Not

Опубликована Март 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 …

Arctic fox dispersal from Svalbard to Canada: one female’s long run across sea ice

Eva Fuglei,

Arnaud Tarroux

Опубликована Июнь 24, 2019

We report the first satellite tracking of natal dispersal by an Arctic fox (Vulpes lagopus) between continents and High-Arctic ecosystems. A young female left Spitsbergen (Svalbard Archipelago, Norway) on 26 March 2018 and reached Ellesmere Island, Nunavut, Canada, 76 days later, after travelling a cumulative distance of 3506 km, bringing her ca. 1789 km away (straight-line distance) from her natal area. The total cumulative distance travelled during the entire tracking period, starting when she left her natal area on 1 March 2018 and ending when she settled on Ellesmere Island on 1 July 2018, was 4415 km. This is among …

Well drilling in permafrost regions: dynamics of the thawed zone

Lev V. Eppelbaum,

Izzy M. Kutasov

Опубликована Июнь 6, 2019

In the cold regions, warm mud is usually used to drill deep wells. This mud causes formation thawing around wells, and as a rule is an uncertain parameter. For frozen soils, ice serves as a cementing material, so the strength of frozen soils is significantly reduced at the ice–water transition. If the thawing soil cannot withstand the load of overlying layers, consolidation will take place, and the corresponding settlement can cause significant surface shifts. Therefore, for long-term drilling or oil/gas production, the radius of thawing should be estimated to predict platform stability and the integrity of the well. It is …

Dynamics and persistence of rabies in the Arctic

Audrey Simon,

Amy Hurford,

Nicolas Lecomte,

Denise Bélanger,

Patrick Leighton,

Olivia Tardy

Опубликована Июнь 5, 2019

Rabies is a major issue for human and animal health in the Arctic, yet little is known about its epidemiology. In particular, there is an ongoing debate regarding how Arctic rabies persists in its primary reservoir host, the Arctic fox (Vulpes lagopus), which exists in the ecosystem at very low population densities. To shed light on the mechanisms of rabies persistence in the Arctic, we built a susceptible–exposed–infectious–recovered (SEIR) epidemiological model of rabies virus transmission in an Arctic fox population interacting with red foxes (Vulpes vulpes), a rabies host that is increasingly present in the Arctic. The model suggests that …

A nematode in the mist: Scottnema lindsayae is the only soil metazoan in remote Antarctic deserts, at greater densities with altitude

Krzysztof Zawierucha,

Craig J. Marshall,

David Wharton,

Karel Janko

Опубликована Май 7, 2019

A decrease in biodiversity and density of terrestrial organisms with increasing altitude and latitude is a well-known ecogeographical pattern. However, studies of these trends are often taxonomically-biased toward well-known organisms and especially those with relatively large bodies, and environmental variability at the local scale may perturb these general effects. Here, we focus on understudied organisms—soil invertebrates—in Antarctic deserts, which are among the driest and coldest places on Earth. We sampled two remote Antarctic sites in the Darwin Glacier area and established an altitudinal gradient running from 210 to 836 m a.s.l. We measured soil geochemistry and organic matter content and …

Pseudolamarckina pseudorjasanensis Dain, 1967 (Foraminifera) as a Kimmeridgian marker species and its significance for biostratigraphy, palaeoecology and palaeobiogeography

Clémentine Peggy Anne-Marie Colpaert,

Boris Leonidovich Nikitenko

Опубликована Март 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 …

Incomplete degradation of lichen usnic acid and atranorin in Svalbard reindeer (Rangifer tarandus platyrhynchus)

Michał Hubert Węgrzyn,

Beata Cykowska-Marzencka,

Monica Alterskjær Sundset,

Paulina Wietrzyk-Pełka,

Agnieszka Galanty

Опубликована Янв. 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. …

Quantifying the relative impact of hunting and oiling on Brünnich’s guillemots in the North-west Atlantic

Morten Frederiksen,

Jannie F. Linnebjerg,

Flemming R. Merkel,

Sabina I. Wilhelm,

Gregory J. Robertson

Опубликована Авг. 6, 2019

Brünnich’s guillemot (Uria lomvia), or thick-billed murre, is an abundant pan-Arctic seabird, but several Atlantic breeding populations are declining. The species is subject to traditional harvest in the important wintering areas off west Greenland and Newfoundland, and has been subject to chronic oil pollution on the east coast of Canada. Until recently, knowledge of winter distribution has been insufficient to assess the impact of these mortality sources on specific breeding populations. We collate existing information on mortality from bag statistics in Greenland and Canada and studies of oiling off Newfoundland, as well as new data on age distribution in the …