Опубликована Сен. 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 …
Опубликована Март 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 …
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 …
Опубликована Март 29, 2019
Dissolved organic carbon, from marine biota excretions and decomposing detritus, is one of the main components of the carbon cycle in the ocean. In this study, an attempt was made to construct maps of the distribution and fluxes of DOC in the Arctic Ocean and the exchanges with the Pacific and Atlantic Oceans. Because of the limited data available a multiple linear regression technique was performed to identify significant relationships between DOC (2200 samples) and hydrologic parameters (temperature and salinity), as well as depth, horizon, latitude and offshore distance. Mapping of the DOC distribution and its fluxes was carried out …
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. …
Опубликована Июнь 27, 2020
The Svalbard Airport composite series spanning the period from 1898 to the present represents one of very few long-term instrumental temperature series from the High Arctic. A homogenized monthly temperature series is available since 2014. Here we increase the resolution from a monthly to daily basis, and further digitization of historical data has reduced the uncertainty of the series. The most pronounced changes in the 120-year record occur during the last three decades. For the 1991–2018 period the number of days warmer than 0 and 5 °C has increased by 25 (21%) and 22 (59%), respectively, per year compared to …
Опубликована Авг. 27, 2020
Chemical signatures in the calcite of shells of polar and subpolar planktonic foraminifera have been frequently used to trace and quantify past meltwater discharge events. This approach assumes that the foraminifera can tolerate low salinity under extended periods. To obtain a first experimental constraint on salinity tolerance of Subarctic foraminifera, we carried out a culturing experiment with specimens of the subpolar species Neogloboquadrina incompta collected in the northern Norwegian Sea off Tromsø in October 2018. The foraminifera were exposed to a gradient of salinities between 35 and 25 PSU. Survival was monitored over 26 days by measuring the extent of …
Опубликована Дек. 23, 2020
Food security is a complex topic defined not just by having enough nutritious food to eat but also by cost, safety and cultural considerations. In Arctic Inuit communities, food security is intimately connected to culture through traditional methods of harvesting country food. In Chesterfield Inlet, Nunavut, community-based research was conducted in collaboration with Chesterfield Inlet community members using interviews and community engagement. Community members were consulted about the design of the interview guide, recruitment of participants, analysis and validation of results. This study aims to develop a theoretical framework of how food security, cultural continuity and community health and well-being …
Опубликована Май 8, 2020
We report for the first time the presence of the globally distributed and extremely polyphagous pest species—the crescent-marked lily aphid (or mottled arum aphid) (Neomyzus circumflexus L.) (Insecta, Hemiptera, Aphididae)—in Greenland. This species, of alien origin, was found on the ornamental plant Salix arbuscula L., imported from Denmark and sold in the main supermarket of Nuuk, the capital of Greenland. As this species is not the preferred host plant of N. circumflexus, the possibility must be considered that the aphids were not imported along with S. arbuscula from the mainland but were transferred from other imported ornamental plants sold in …
Опубликована Июнь 11, 2020
Humeri have been useful bones in taxonomic determinations of extinct penguins. In the context of neontological taxonomic studies, however, their potential remains unsatisfactorily explored. Here, the variation of the overall closed-outline shape of 60 humeri, assignable to five genera of extant penguins, was investigated. A set of normalized outlines was quantified via elliptical Fourier analysis and subjected to linear discriminant analysis on principal component scores extracted from harmonic coefficients. These geometric representations proved to be a source of easily extractable genus-level taxonomic information. The constructed model provided meaningful discrimination between taxa: the first two linear discriminants captured almost 90% of …