Polar Research (E-Journal)
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Effects of temperature and fertilization on the structure of total versus active bacterial communities from sub-Antarctic seawater exposed to crude oil and diesel fuel
No full textPolar environments are exposed to the risk of oil pollution. However, there is limited knowledge regarding how the variation of physicochemical factors influencing biodegradation may affect bacterial community structure. The effects of temperature (4, 10 and 20°C) and organic fertilization (Inipol EAP 22) on community structure and diversity of bacteria inhabiting Kerguelen sub-Antarctic waters were studied in crude- and diesel-amended microcosms. Dynamics of total (i.e., 16S rDNA-based) and metabolically active (i.e., 16S rRNA-based) bacterial community structure and diversity were monitored using capillary-electrophoresis single-strand conformation polymorphism. Results showed that total and active community structures were differently influenced by temperature and fertilization in the presence of hydrocarbons. Both fertilization and temperature induced changes in total community structure in the presence of crude oil and diesel. However, temperature showed a limited influence on active community structure, and fertilization induced changes in the presence of crude oil only. Simpson’s index decreased for total bacterial communities at all temperatures in the presence of crude oil and diesel, whereas a lower reduction was observed for active bacterial populations. In the presence of fertilizer, the diversity of the whole community approached control values after seven incubation weeks; this was not observed for the active bacterial community. This study evidenced qualitative differences in total and active bacterial community structures of Kerguelen seawaters in the presence of hydrocarbons and different responses relative to variation in temperature and fertilization. These factors and hydrocarbons composition have to be taken into account to understand bacterial community dynamics after an oil spill.Keywords: Oil hydrocarbons; Inipol EAP 22; temperature; 16S rDNA/rRNA; sub-Antarctic seawaterCitation: Polar Research 2013, 32, 18521, http://dx.doi.org/10.3402/polar.v32i0.1852
New at-sea records of pelagic seabirds in the South Atlantic Ocean and Antarctica
No full textDuring ship-based seabird surveys in the south Atlantic and Antarctica in the austral summers of 1994/95, 2009, 2010, 2011 and 2012, we documented at-sea distributions of Buller’s albatross (Thalassarche bulleri), Atlantic petrel (Pterodroma incerta), soft-plumaged petrel (Pterodroma mollis), Kerguelen petrel (Lugensa brevirostris) and great-winged petrel (Pterodroma macroptera). In some cases, sightings were considered as extralimital, but for other species updating their distributions in the literature seems warranted. Atlantic petrel, for example, has been regularly observed in the Drake Passage and north of the Antarctic Peninsula for about 30 years, but the distribution of this species has not been updated in the literature. The observations reported here will contribute to update the at-sea distributions of these species and to changes in their distributions.Keywords: Seabirds; Antarctica; South Atlantic Ocean; distribution(Published: 17 May 2013)Citation: Polar Research 2013, 32, 18972, http://dx.doi.org/10.3402/polar.v32i0.1897
Review of Svalbard life, by Paul Wassmann & Rudi Cayers
No full textThe author, Paul Wassmann, is a professor of marine biology at the University of Tromsø, and the designer, Rudi Caeyers, is a photographer and graphic designer at the same university. Svalbard life is a generously illustrated coffee-table book on the Svalbard Archipelago and surrounding seas.
(Published: 11 December 2013)
Citation: Polar Research 2013, 32, 23400, http://dx.doi.org/10.3402/polar.v32i0.2340
Diversity of hard-bottom fauna relative to environmental gradients in Kongsfjorden, Svalbard
No full textA baseline study of hard-bottom zoobenthos in relation to environmental gradients in Kongsfjorden, a glacial fjord in Svalbard, is presented, based on collections from 1996 to 1998. The total species richness in 62 samples from 0 to 30 m depth along five transects was 403 species. Because 32 taxa could not be identified to species level and because 11 species are probably new to science, the total number of identified species was 360. Of these, 47 species are new for Svalbard waters. Bryozoa was the most diverse group. Biogeographic composition revealed features of both Arctic and sub-Arctic properties of the fauna. Species richness, frequency of species occurrence, mean abundance and biomass generally decreased towards the tidal glaciers in inner Kongsfjorden. Among eight environmental factors, depth was most important for explaining variance in the composition of the zoobenthos. The diversity was consistently low at shallow depths, whereas the non-linear patterns of species composition of deeper samples indicated a transitional zone between surface and deeper water masses at 15-20 m depth. Groups of ‘‘colonial’’ and ‘‘non-colonial’’ species differed in diversity, biogeographic composition and distribution by location and depth as well as in relation to other environmental factors. ‘‘Noncolonial’’ species made a greater contribution than ‘‘colonial’’ species to total species richness, total occurrence and biomass in samples, and were more influenced by the depth gradient. Biogeographic composition was sensitive to variation of zoobenthic characteristics over the studied depth range. A list of recorded species and a description of sampling sites are presented.Keywords: Zoobenthos; hard substrata; Svalbard; Kongsfjorden; biodiversity; environmental gradients.To access the supplementary material for this article, please see supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2013, 32, 11208, http://dx.doi.org/10.3402/polar.v32i0.1120
Current knowledge of the Tardigrada of Svalbard with the first records of water bears from Nordaustlandet (High Arctic)
No full textThe first investigations of the tardigrades of Svalbard took place in the early 20th century and 30 papers on the subject have been published to date. In this article, we summarize available information on the distribution of tardigrades in this Arctic archipelago with remarks on the dubious species and records. Additionally, we examined 28 new moss, lichen and soil samples collected from the islands of Nordaustlandet, Edgeøya and Prins Karls Forland. These samples yielded 324 specimens, 15 exuvia and 132 free-laid eggs belonging to 16 limnoterrestrial species (Heterotardigrada and Eutardigrada). These include five first records of water bears from Nordaustlandet, eight new records for Edgeøya and four for Prince Karls Forland. The most dense population of tardigrades was found in a sample with 253 specimens/10 g of dry material and the least dense population in a sample with three specimens/10 g of dry material. The most frequently recorded species in samples collected in this study were Testechiniscus spitsbergensis Scourfield, 1897, Macrobiotus harmsworthi harmsworthi Murray, 1907, and M. islandicus islandicus Richters, 1904. This article also provides the first ever scanning electron microscope photomicrographs of Tenuibiotus voronkovi Tumanov, 2007.Keywords: Checklist; Edgeøya; new species; Prins Karls Forland; soil fauna; Svalbard biodiversity(Published: 20 November 2013)To access the supplementary material for this article, please see Supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2013, 32, 20886, http://dx.doi.org/10.3402/polar.v32i0.2088
Environmental conditions, particle flux and sympagic microalgal succession in spring before the sea-ice break-up in Adélie Land, East Antarctica
No full textData pertaining to environmental conditions, sympagic (sea ice) microalgal dynamics and particle flux were collected before the spring ice break-up 2001 in Pierre Lejay Bay, adjacent to the Dumont d'Urville Station, Petrel Island, East Antarctica. An array of two multiple sediment traps and a current meter was deployed for five weeks, from 8 November to 6 December 2001. The sea-ice chlorophyll a and particulate organic carbon (POC) averaged 0.6 mg l−1 (30 mg m−2) and 20 mg l−1 (1 g m−2) near the coast. The POC export flux that reached a maximum of 79 mg m−2 d−1 during the study period was high compared to the one for the Weddell Sea. The flux was homogeneous from the surface to 47 m depth and increased sharply 33 days before the effective ice break-up. A north-western progressive vector of currents (i.e., Lagrangian drift) in the sub-ice surface waters was demonstrated. Bottom ice, platelet ice and under-ice water at 5 m were characterized by differences in colonization and short-term succession of microalgae.Keywords: Land-fast ice; oceanic short-term regime; POM flux; sympagic communities; East Antarctica(Published: 8 August 2013)Citation: Polar Research 2013, 32, 19675, http://dx.doi.org/10.3402/polar.v32i0.1967
Sources and geographic heterogeneity of trace metals in the sediments of Prydz Bay, East Antarctica
No full textIn this study, we have determined the contents and distribution of zinc and cadmium in the surface sediments from Prydz Bay, East Antarctica. The main sources of the trace elements and their geographic heterogeneity, and the relation between Zn and Cd, are discussed based on the cluster analysis, principle component analysis and considerations of biogenic and lithogenic inputs. The results show that the contents of trace metals range from 34.6 to 96.6 mg kg-1 for Zn, and from 0.254 to 0.441 mg kg-1 for Cd. Calculations of the enrichment factor indicated no significant anthropogenic impact. Biogenic and lithogenic inputs are the main sources of trace metals. They are almost equal for Zn and Cd at the Amery Ice Shelf edge, while the continental shelf and deep ocean are dominated by biogenic inputs. The contribution of biogenic inputs is much higher for Zn than for Cd at the deep ocean. Calculations of biogenic trace metals revealed different relationships between biogenic Zn and biogenic Cd, which reflect the biological uptake by phytoplankton in the water column.Keywords: Trace elements; sources; enrichment factor; cluster analysis; principal component analysis; Antarctica.(Published: 24 July 2013)Citation: Polar Research 2013, 32, 20049, http://dx.doi.org/10.3402/polar.v32i0.2004
Quantifying polynya ice production in the Laptev Sea with the COSMO model
No full textArctic flaw polynyas are considered to be highly productive areas for the formation of sea-ice throughout the winter season. Most estimates of sea-ice production are based on the surface energy balance equation and use global reanalyses as atmospheric forcing, which are too coarse to take into account the impact of polynyas on the atmosphere. Additional errors in the estimates of polynya ice production may result from the methods of calculating atmospheric energy fluxes and the assumption of a thin-ice distribution within polynyas. The present study uses simulations using the mesoscale weather prediction model of the Consortium for Small-scale Modelling (COSMO), where polynya area is prescribed from satellite data. The polynya area is either assumed to be ice-free or to be covered with thin ice of 10 cm. Simulations have been performed for two winter periods (2007/08 and 2008/09). When using a realistic thin-ice thickness of 10 cm, sea-ice production in Laptev polynyas amount to 30 km3 and 73 km3 for the winters 2007/08 and 2008/09, respectively. The higher turbulent energy fluxes of open-water polynyas result in a 5070% increase in sea-ice production (49 km3 in 2007/08 and 123 km3 in 2008/09). Our results suggest that previous studies have overestimated ice production in the Laptev Sea.Keywords: Mesoscale modelling; Laptev Sea; polynya; ice production.(Published: 17 October 2013)Citation: Polar Research 2013, 32, 20922, http://dx.doi.org/10.3402/polar.v32i0.2092
Reactive nitrogen and sulphate wet deposition at Zeppelin Station, Ny-Ålesund, Svalbard
No full textAs a potent fertilizer, reactive nitrogen plays an important role in Arctic ecosystems. Since the Arctic is a nutrient limited environment, changes in nitrogen deposition can have severe impacts on local ecosystems. To quantify the amount of nitrogen deposition through snow- and rain events, precipitation sampling was performed at Zeppelin station, Svalbard, from November 2009 until May 2011. The samples were analysed for NO3-, nss-SO42- and NH4+ concentrations, and the deposition of single precipitation events was calculated using precipitation observations from Ny-Ålesund. The majority of observed events showed concentrations ranging from 0.01 to 0.1 mg L-1 N for NO3- and NH4+ and 0.02 to 0.3 mg L-2 S for nss-SO42-. The majority of calculated deposition was in the range between 0.01 to 0.1 mg m-2 N for NO3- and NH4+ and 0.02 – 0.3 mg m-2 S for nss-SO42-. The budget was controlled by strong deposition events, caused by long lasting precipitation episodes that lasted for several days and which had raised concentrations of nitrogen and sulphur. Three future scenarios of increasing precipitation in the Arctic were considered. The results showed that deposition is mainly controlled by the amount of precipitation, which leads to the conclusion that increased precipitation might cause increases in deposition of the same magnitude.Keywords: Nitrogen; sulphur; Arctic; precipitation; sampling; NSINK.(Published: 15 April 2013)Citation: Polar Research 2013, 32, 19136, http://dx.doi.org/10.3402/polar.v32i0.1913
Review of Antarctica: global science from a frozen continent, edited by David W.H. Walton
No full textWhen I agreed to review this book, I assumed I would receive a collation of edited literature reviews exploring various aspects of Antarctic science, similar to several other volumes that are sitting on my office bookshelves. But Antarctica: global science from a frozen continent is not that type of book. Instead it is a handsomely produced volume, filled with a large number of excellent-quality colour photographs and figures, which can just as easily be in a high school or public library as in a university professor’s research collection.
(Published: 3 July 2013)
Citation: Polar Research 2013, 32, 21696, http://dx.doi.org/10.3402/polar.v32i0.2169