Morphology of seamounts at the Mendeleev Rise, Arctic Ocean

Evgeny Gusev,

Pavel Rekant,

Valery Kaminsky,

Alexey Krylov,

Andrey Morozov,

Sergey Shokalsky,

Sergey Kashubin

Published: April 10, 2017

Geological and geophysical studies undertaken during the Russian Arktika-2012 Expedition of 2012 produced evidence of basement outcrops on the steep slopes of the Mendeleev Rise seamounts. Observations of the outcrops from research submarines showed that part of the steep slopes interpreted as basement outcrops based on seismic data were overlain by a light sediment cover. The actual areas of the basement outcrops are therefore much less than indicated by the seismic data alone. The outcrops found are of 5–10 to 100–200 m and are often stretched along some hypsometric level or arranged obliquely, crossing a slope at an angle to …

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

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 …

Interannual variability in hydrography and water mass distribution in Hornsund, an Arctic fjord in Svalbard

Agnieszka Promińska,

Waldemar Walczowski,

Eva Falck

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 …

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

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 …

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

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 …

Nutrient uptake controls and limitation dynamics in north-east Greenland streams

Catherine L. Docherty,

Tenna Riis,

David M. Hannah,

Simon Rosenhøj Leth,

Alexander M. Milner

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 …

Embracing Online Platforms: A Game-Changer for UPSC Preparation

Pooja Kashid

Created: Aug. 7, 2023

Unlocking the Potential: Online platforms have revolutionized UPSC preparation, offering abundant quality content, personalized mentorship, and unparalleled flexibility. With RAUIAS as a prime example, aspirants now have access to top-notch resources and guidance to achieve their dreams of serving the nation.

Dynamics and persistence of rabies in the Arctic

Audrey Simon,

Amy Hurford,

Nicolas Lecomte,

Denise Bélanger,

Patrick Leighton,

Olivia Tardy

Published: June 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 …

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

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. …

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

Published: Aug. 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 …