Polar Research (E-Journal)
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Networks of international co-authorship in journal articles about Antarctic research, 1998–2015
No full textThis study seeks insight into the social structure of Antarctic research from 1998 to 2015 by examining peer-reviewed journal articles listed in the Science Citation Index of the Web of Science database. This study identifies leading countries in peer-reviewed journal article output and applies social network analysis methods to identify countries where authors are collaborating with those affiliated with organizations in different countries. The results show that the number of publications on Antarctica and the proportion of international research collaboration increased from 23.0 to 33.2% during the period of time being considered. The number of articles published by authors affiliated with institutions in emerging countries such as China, Turkey, Brazil and South Korea rose, whereas the proportion of articles published by authors affiliated with institutions in the United States decreased. The largest proportion of academic publications pertaining to Antarctic research was within the natural sciences. Within this broad field, the majority of publications fell within Earth and related environmental sciences and the biological sciences. Social network analysis shows that Antarctic research moved towards a network, in which researchers are internationally more connected than ever before, with countries such as the United States, the United Kingdom, Germany, France and Australia in central positions. Sweden, Belgium and the Netherlands did not account for a high percentage of academic contributions but were still notable for their multinational collaborative research
Post-depositional loss of nitrate and chloride in Antarctic snow by photolysis and sublimation: a field investigation
No full textNitrate in snow is subject to post-depositional processing, which leads to a net loss and redistribution within the snowpack. The relative importance of post-depositional loss processes such as the volatilization of nitric acid (HNO3) and photolysis of nitrate has long been debated. Changes in nitrate and chloride concentrations in the snowpack were investigated at H128 (69°23.584’S, 41°33.712’E), an Antarctic coastal site approximately 100 km from Syowa Station in East Antarctica from December 2015 to February 2016. Results indicate that chloride migrated to deeper sites within the snowpack under the influence of water vapour movement. Moreover, 50% of the nitrate on surface snow was lost to photolysis, and approximately 20% of the nitrate was absent at a depth of 40 cm. To enhance our knowledge of the Antarctic geochemical cycle, this study is the first to suggest chloride ion movement in snowpacks or significant nitrate loss for any Antarctic coastal site
Does foraminiferal test size reflect changes in palaeoenvironmental conditions?—a case study from the southern Svalbard shelf
No full textAlthough the environmental factors influencing the growth rate and reproduction of benthic foraminifera are known, the relationship between foraminifera test size and environmental variables remains unclear, especially on geological timescales. In this article, we present two records of benthic foraminiferal test size over the last 14 000 years from the southern Svalbard shelf. We use statistical correlation to relate test size changes with environmental conditions recorded by other proxies, including benthic δ18O and δ13C, foraminiferal flux and abundance, and relative abundances of different ecologically indicative foraminiferal groups. The general trends in test size were relatively consistent between the two cores. Still, we found that none of the analysed proxies was statistically correlated with the test size in both records. This leads to a conclusion that foraminifera size is primarily impacted by local oceanographic conditions. These local conditions are partly influenced by global oceanographic transitions. Therefore, large-scale changes can have a secondary impact on foraminiferal test size. The analysis of test size correlation between species similarly revealed that not all species react consistently to environmental changes. Our results indicate that foraminiferal test size cannot be used as a universal and straightforward proxy, but in combination with other methods it can yield valuable palaeoenvironmental information
Growth-related changes in salt gland mass in gentoo and chinstrap penguin chicks
No full textThe salt gland is a well-developed osmoregulation organ in marine birds, and its relative size often reflects an individual’s feeding environment and osmoregulation capability. The development and functions of salt glands have been described for the Adélie penguin (Pygoscelis adeliae), but this information has been poorly documented in the other two pygoscelid species: gentoo (P. papua) and chinstrap penguins (P. antarcticus). To describe the growth-related changes in salt gland masses in relation to chick growth, we measured the wet mass of the salt glands collected from dead gentoo and chinstrap chicks during the early breeding period. The mass of the salt glands was linearly proportional to their body measurements, especially to body mass, in both species, and no significant difference was detected between the two species. Penguins are obligate marine dwellers throughout their life cycle, and the development of the salt gland in penguin chicks suggests that their ability to regulate dietary osmotic stress begins at an early stage of development after hatching. Furthermore, the linear relationship between the gland mass and body mass also suggests that the osmoregulation capability may continue to develop as penguin chicks grow. This descriptive note provides novel and quantitative information on the early developmental pattern of salt glands in gentoo and chinstrap penguins
Sharing country food: connecting health, food security and cultural continuity in Chesterfield Inlet, Nunavut
No full textFood 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 are interconnected to allow for a richer understanding of how increased shipping, climate change and social changes are impacting community members. In Chesterfield Inlet, harvesting and consuming country food (e.g., seal) is perceived as the mechanism that connects food, culture and community health. Sharing of freshly harvested country food supports the food security of community members without hunters in their families, aligns with hunters’ cultural beliefs and promotes community health and well-being. Changes that reduce a hunter’s success in harvesting country food limit her or his ability to share country food, which negatively impacts community health and well-being. The results of this study support existing community efforts to adapt to changes that impact harvesting success
Reconstructing the Little Ice Age extent of Langfjordjøkelen, Arctic mainland Norway, as a baseline for assessing centennial-scale icefield recession
No full textCurrent warming in the Arctic is occurring at a rate two to three times higher than that of the rest of the world, leading to rapid glacier wastage. In Arctic mainland Norway, the plateau icefield Langfjordjøkelen has experienced the greatest mass loss of all Norwegian glaciers (excluding Svalbard) in recent decades. In this article, we examine this decline in a centennial-scale context through geomorphological mapping and the analysis of historical aerial photographs and maps. This allows Langfjordjøkelen’s maximum Little Ice Age extent (ca. 1925) to be reconstructed, providing an important baseline for a long-term assessment of icefield change. At the LIA maximum, Langfjordjøkelen covered an area of 14.9 km2. A comparison of the LIA dimensions with the icefield extent in 1891/1902, as displayed on a historical map, reveals a substantial overestimation of the map-based glacier outline. The post-LIA evolution of Langfjordjøkelen has been characterized by sustained high rates of glacier recession. By 2018, the icefield had lost 57% (8.5 km2) of its original LIA area, at a decadal rate of 9%, and its outlet glaciers had reduced in average length by 42% (1 km), at an annual rate of 11 m. Langfjordjøkelen’s percentage area decline has been greater than that of Norwegian ice masses at lower latitudes where comparable long-term glacier change data are available. This indicates that there is a significant latitudinal variation in Norwegian glacier response to 20th century warming, likely influenced by an enhanced warming signal in Arctic Norway compared to the rest of the Norwegian mainland
Effect of ikaite precipitation on phosphate removal in sea ice
No full textIkaite (CaCO3·6H2O) precipitation in sea ice has been shown to affect CO2 exchange between the atmosphere and ocean. A laboratory study indicates that it could also co-precipitate phosphate from sea ice, which has the potential to affect sea-ice biogeochemical processes. However, the relative importance of ikaite precipitation on phosphate removal under sea-ice conditions remains unknown. We investigated ikaite precipitation in both frost flowers and seaice (under two scenarios: flooded by seawater and non-flooded) in an outdoor sea-ice mesocosm experiment, and in sea ice under natural conditions in north-eastern Greenland. The ice mesocosm experiment showed that ikaite was highly enriched in frost flowers with a concentration of up to 350 µmol·kg–1. Ikaite was also detected in the surface layer of sea ice, ranging from ca. 13 µmol·kg–1 in the non-flooded ice to ca. 95 µmol·kg–1 in the flooded ice. However, under all these conditions, no phosphate co-precipitation with ikaite was observed. The field study in Greenland showed similar results: ikaite was detected in surface ice with an average concentration of 13.8 µmol·kg–1, but no phosphate removal due to ikaite precipitation was observed. These results suggest that the impact of ikaite precipitation on phosphate and the sea-ice ecosystem might not be as significant as imagined previously
Ichnodiversity and bathymetric range of microbioerosion traces in polar barnacles of Svalbard
No full textThis first comprehensive investigation of microbioerosion traces in polar barnacles addresses two bathymetrical transects from the intertidal down to subtidal water depths in two different carbonate factories in the Svalbard Archipelago: the bay Mosselbukta and the ocean bank Bjørnøy-Banken. Scanning electron microscopy of epoxy resin casts of barnacle shells yielded 20 different microendolithic bioerosion traces, probably produced by cyanobacteria (three), chlorophytes (two), rhodophytes (one), sponges (one), foraminifera (three), fungi (nine) and bacteria (one). The lowest ichnodiversity in both locations was observed in the shallow euphotic zone and is likely a result of strong temperature fluctuations, extreme seasonality of light levels and episodic sea-ice cover. At 25–150 m water depth, the ichnodiversity remains relatively constant (9–13 ichnospecies), albeit with differing ichnospecies composition, generally dominated by borings from chlorophytes and fungi. Ichnotaxa at Mosselbukta and Bjørnøy-Banken were similar in numbers but differed in abundance and slightly also in ichnospecies composition. Statistical tests indicate that water depth (affecting the availability of light) is the most significant driver for the development of different microbioerosion trace assemblages across the bathymetrical transects. In contrast, no significant differences in ichnodisparity were found, indicating a comparable suite of architectural designs of the micro-borings throughout bathymetry and location. The comparison of our results with literature data confirms a decrease in ichnodiversity from lower to higher latitudes, although targeted bioerosion analyses from other polar environments are needed to gain a more complete picture of the role of bioerosion in polar carbonate factories
Pathogen surveillance in Southern Ocean pinnipeds
No full textKnowledge of the health status and potential effect of disease outbreaks among Southern Ocean fauna may be decisive for its conservation. We assessed the exposure and infection of Antarctic fur seals (Arctocephalus gazella, AFS) and Southern elephant seals (Mirounga leonine, SES) to parapoxvirus, Phocid alphaherpesvirus-1 (PhHV-1), smooth Brucella spp. and Toxoplasma gondii. AFS (n = 65) serum and swab samples, and SES (n = 13) serum samples from the sub--Antarctic island of Bouvetøya (54°25’S, 03°22’E) were collected during two austral summers (2014/15, 2017/18). Three polymerase chain reaction (PCR) tests amplifying the DNA polymerase, B2L and GIF parapoxvirus genomic regions were performed, investigating DNA from mucosal swab samples. The glycoprotein B gene was targeted to detect PhHV-1 viral DNA. Sera were assayed for T. gondii and smooth Brucella spp. antibodies with indirect enzyme-linked immunosorbent assays. Parapoxvirus PCR amplicons of the expected size were generated in two of the 29 AFS pups (nasal swabs, 2014/15), targeting the B2L (n = 2) and DNA polymerase (n = 1) genes, whereas the GIF PCR did not amplify target sequences. The PCR amplicons were sequenced and blasted in GenBank, revealing highest similarity with a seal parapoxvirus, confirming the presence of the virus in AFS for the first time. No PhHV-1 amplicons were generated, and antibodies against T. gondii or smooth Brucella spp. were not detected. Our data indicate that these seals are host for parapoxvirus but are neither exposed to smooth Brucella spp. nor T. gondii. Evidence of PhHV-1 shedding was not detected
Temporal and spatial change in the relationship between sea-ice motion and wind in the Arctic
No full textThis paper examines the temporal and spatial change in the characteristics of sea-ice motion in the Arctic. Ice motion is generally expressed by a motion at a constant ratio (wind factor) of wind speed, with a certain angle (turning angle) from the wind direction, and ocean currents. This study aimed to reveal the recent changes of the wind factor and turning angle using satellite observation data. We first prepared a daily ice-velocity data set from data for 2003–2017 collected by the satellite microwave sensor Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) and its successor, AMSR2. Monthly values of the wind factor and turning angle were calculated by a least squares technique, based on the linear relationship between sea-ice velocity and geostrophic wind velocity. The daily variation of sea-ice motion was strongly correlated with that of the wind. The wind factor and turning angle changed regionally, seasonally and interannually. With regard to long-term trends, the wind factor has increased in almost all areas of the Arctic. However, the trend of increase stopped around 2010, especially around the central Arctic