Polar Research (E-Journal)
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Influence of meteorological parameters on atmospheric CO2 at Bharati, the Indian Antarctic research station
No full textDuring the 35th Indian Scientific Expedition to Antarctica, measurements of atmospheric carbon dioxide (CO 2 ) were carried out using a Li-Cor CO 2 /H 2 O analyser at Bharati, the Indian Antarctic research station. This study examines the short-term variability of atmospheric CO 2 during the austral summer (January–February) of 2016. An average of 396.25 ± 4.20 ppm was observed during the study period. Meteorological parameters such as relative humidity, precipitation, wind speed, air temperature and atmospheric boundary layer height in conjunction with photosynthetically active radiation, the biological activity indicator which modulates atmospheric CO 2 concentration have been investigated. High wind speed (>20 m s −1 ) combined with precipitation scavenges CO 2 in the atmosphere, resulting in low concentrations at the study site. The lowest CO 2 concentration of 385 ppm coincided with heavy precipitation of 15 mm during study period. Statistical analysis of the data shows that precipitation and relative humidity independently correlated 55% (r = −0.55) and 32% (r = −0.32), respectively, with the variability of CO 2 mixing in the atmosphere at the study site. Atmospheric CO 2 was significantly correlated with precipitation alone with a p value of 0.003. Further, multiple regression analysis was performed to test the significant relation between variability of atmospheric CO 2 and meteorological parameters. Long-range air-mass transport analysis depicted that the majority of the air masses are reaching the study site through the oceanic region
Food resources influence levels of persistent organic pollutants and stable isotopes of carbon and nitrogen in tissues of Arctic foxes (Vulpes lagopus) from the Pribilof Islands, Alaska
No full textThe Arctic fox (Vulpes lagopus) is a small canid with a circumpolar Arctic distribution. Several subspecies are recognized, including a subspecies known as the Pribilof fox (V. l. pribilofensis) endemic to the Pribilof Islands of Alaska, USA. Pribilof fox tissues were collected from the islands of St. Paul (n = 38) and St. George (n = 13). Levels of persistent organic pollutants (POPs) and stable isotopes of carbon and nitrogen were measured and the findings related to sex, age class, island and access to anthropogenic food resources using ANOVA and principal component analysis. The rank order for POPs in fat was polychlorinated biphenyls (ΣPCBs) > chlordanes (ΣCHLs) ≫ hexachlorocyclohexanes (ΣHCHs) > DDTs (ΣDDTs) > hexachlorobenzene (HCB) ~ polybrominated diphenyl ethers (ΣPBDEs). Adult females had lower mean levels of most POPs (ΣPCBs, ΣCHLs, ΣHCHs, ΣDDTs) and lower δ15N values than adult males. Foxes on St. Paul had significantly higher levels of most POPs than those on St. George, though St. George foxes were significantly higher in HCB. Foxes with high probability of access to anthropogenic foods had significantly lower levels of ΣDDTs and lower δ15N values than foxes with a low probability of access. The observed differences in contaminant and stable isotope levels were consistent with fox use patterns of different food resources. POP concentrations in the tissues of some Pribilof foxes, especially from St. Paul, were higher than those associated with thresholds for adverse health effects. POPs may therefore be a factor for consideration in the conservation of Pribilof foxes
Investigating the effect of Arctic sea routes on the global maritime container transport system via a generalized Nash equilibrium model
No full textThis paper proposes a generalized Nash equilibrium model to investigate if Arctic routes can be used as a “relief valve” for current intercontinental sea routes. This model is presented as a Stackelberg form, where the shipping companies correspond to the leaders and the customers correspond to the followers. The competition among shipping companies (leaders), which seek to maximize their profits, can be represented as a generalized Nash equilibrium and solved by the alternating direction method of multipliers algorithm, based on penalization. On the basis of the competition results, the customers (followers) choose the optimal shipping companies; this results in the allocation of container volumes on different sailing routes, which can be described by a logit-type multi-path assignment model. Different scenarios in our modelling show that as shipping speeds decrease through the use of Arctic sea routes, company profits increase. In particular, as navigable days on the Northern Sea Route (NSR) increase, the container trade will increasingly tilt towards this route and shipping companies using it will gain more profits than they did before the opening of this route. At the same time, the proportion of container volume through the Suez Canal will be reduced because it will be less profitable
The magnetic method as a tool to investigate the Werenskioldbreen environment (south-west Spitsbergen, Arctic Norway)
No full textWe used a novel approach of applying magnetic analyses to investigate the material released from the receding glacier Werenskioldbreen on Spitsbergen, Svalbard, Arctic Norway. Surface sediments were taken from the bay Nottinghambukta and the Werenskioldbreen foreland, along two main proglacial streams. Magnetic analyses, namely the low-field mass magnetic susceptibility, anhysteretic susceptibility mass normalized and hysteresis parameters, served to determine magnetic properties and identify the magnetic composition of the study material. We selected two distinct types of sediments. The first group, consisting of magnetite and pyrrhotite, has more single-domain grains in comparison to the second one, containing only magnetite. In the second group, multi-domain particles dominate. Deposits from the north stream, glacier river and an area close to the estuary of Nottinghambukta include magnetite and pyrrhotite. Magnetite was found in the south stream and in the outside part of the bay. Magnetic composition reflects different source rocks of sediments. This study demonstrates the utility of the magnetic method in analysing the current state of glacier environments
Current logistical capacity is sufficient to deliver the implementation and management of a representative Antarctic protected area system
No full textAntarctica’s terrestrial ecosystems are vulnerable to impacts resulting from climate change and local human activities. The Antarctic Treaty System (ATS) provides for the designation of protected areas through the Protocol on Environmental Protection to the Antarctic Treaty. Unsystematic use of agreed management tools, including Antarctic Specially Protected Areas (ASPAs), has resulted in a protected area system lacking representation across the full range of Antarctic terrestrial ecosystems and Antarctic Conservation Biogeographic Regions (ACBRs). Systematic Conservation Planning (SCP) methods provide established mechanisms to fulfil ATS protected area designation goals. However, how would a continent-wide ASPA system be delivered should appropriate sites be identified using SCP or other methods? Although the rate of area protection has slowed recently, we show that newer Consultative Parties to the Antarctic Treaty are increasingly active as ASPA proponents and may have scope for further engagement with protected area management activities. Furthermore, all 16 ACBRs were found to be within the operational footprint of at least two Parties, indicating that this current logistical footprint could support the implementation and management of a continent-wide ASPA system. Effective management of a representative Antarctic protected areas system could be delivered through greater participation by those Parties with currently more limited protected area management responsibilities and greater use of remote-sensing technologies for protected area monitoring, where appropriate. Crucially, political will to implement an ASPA system identified through SCP approaches may be greater once a pragmatic means of delivery and effective management has been identified
Adult survival of Arctic terns in the Canadian High Arctic
No full textArctic tern (Sterna paradisaea) populations are thought to be in decline across much of their range. For long-lived seabirds, determining adult survival rates is key to understanding current population trends and predicting trajectories. We therefore examined adult survival of terns banded at our field site in the Canadian High Arctic between 2007 and 2016. Apparent adult survival was 0.883, comparable to values for other tern species and for other Arctic larids. However, using this survival rate plus first year survival values from a recent study in Iceland, we project a declining trend for terns in the Canadian High Arctic, consistent with recent reports from local ecological knowledge and limited regional surveys. Our data suggest that low adult survival is not responsible for declining tern populations, and that studies should investigate whether dispersal to new nesting locations may be underway, or that young terns are not surviving well or recruiting to the population
Large versus small zooplankton in relation to temperature in the Arctic shelf region
No full textClimate change results in the alteration of the size structure of plankton, which consequently may affect higher trophic levels, such as planktivorous seabirds. In this study Laser Optical Plankton Counter measurements were performed over seven summer seasons (2010–2016) to test the ratio of large versus small zooplankton in relation to environmental conditions. Investigated transects were repeated during the same time of the year (July/August) in different zones of the West Spitsbergen Shelf crossing the Arctic front. The plankton particles were grouped into two size fractions: “Calanus”, potentially consisting of a majority of the high-energetic, older life stages of the preferred prey for little auk (Alle alle) and the “small” fraction including less preferred items. The vertical availability of the Calanus fraction was tested on the background of usually abundant smaller zooplankton, which may hinder the detection of larger zooplankters by little auk. Larger zooplankton were found closer to the coast, in the upper 20-m depth layer in years characterized by significantly lower mean temperatures. Potential availability of prey for the little auk thus could be higher in colder years than in warmer years. Additionally, our study indicated the tendency of the small plankton fraction to concentrate near the locations of the highest chlorophyll fluorescence, in the 20–30-m water layer. The high spatial and temporal resolution of the data indicated a variation in the proportion of large versus small zooplankton, and thus in the availability of Calanus to little auk with respect to temperature
Review of Priestley’s progress: the life of Sir Raymond Priestley, Antarctic explorer, scientist, soldier, academician, by Mike Bullock, Jefferson, NC: McFarland, 2017, 197 pp., £38.95 (paperback), ISBN 978-0-7864- 7805-7
No full textInfluence of nest burrow microclimate on chick growth in a colonial High-Arctic seabird, the little auk
No full textThe growth of seabird chicks is affected by various environmental conditions. Although species nesting in burrows may thereby reduce the effects of environmental conditions, they are still dependent on the nest microclimate. We investigated the influence of nest microclimate on chick growth in the little auk (Alle alle), a colonial High-Arctic seabird breeding in Hornsund (south-west Spitsbergen). We recorded air temperature inside and outside 10 active nests during two phases of breeding and during post-breeding period (no birds inside). We found that temperatures differed significantly among the nests. Air temperatures in nests located at higher altitudes were significantly higher, which can be attributed to the absorption of the Sun’s rays at a higher angle, resulting in a greater heat flux. Nest chamber temperatures were significantly higher (by 0.46°C) than ambient ones. During the post-breeding period, 24 hr cycle nest temperatures were more stable than ambient temperatures, indicating the important insulating function of nest burrows. Little auk chicks grew faster in nests with higher mean temperatures. In the first phase of chick growth (15th to 18th day of life), a 1°C difference in the nest temperature resulted in differences in head–bill length and body mass growth of 0.80 mm and 0.76 g per day, respectively. Our study demonstrates the importance of the thermal nest environment in determining chick growth in a species breeding in harsh High-Arctic conditions
Methane emissions are lower from reindeer fed lichens compared to a concentrate feed
No full textMethane emissions from reindeer ( Rangifer tarandus tarandus ) fed lichens (mainly Cladonia stellaris ) and a concentrate feed were determined using open-circuit respirometry. The lichen diet was low in crude protein (< 2.6% of dry matter [DM]), starch (6.0% DM) and acid detergent lignin (2.0% DM) compared to the concentrate feed (12.7, 22.5 and 7.2% DM, respectively), and high in neutral detergent fibre (82.2% DM versus 34.8% DM in concentrate feed). The feeds were offered in equal amounts (ca. 0.440 kg DM) 2 h after initiating methane recordings in the respiration chamber. The reindeer were adapted to these diets for > 4 weeks prior to experiments and methane emissions recorded for two separate 23 h periods for each diet. Methane emissions increased on average by 0.93 g/h (or by 5.8 times) in the first hour after feeding the concentrate feed, while emissions remained unchanged after the intake of lichens. Mean methane emissions from reindeer (n = 5) were 7.5 ± 0.54 (SE) g CH 4 day −1 when fed lichens, compared to a higher emission ( p = 0.001) of 11.2 ± 0.54 g CH 4 day −1 on the concentrate diet. The mean proportion of gross energy intake lost as methane was 5.2 ± 0.37% on the lichens and 7.6 ± 0.37%, or some 50% higher, on the concentrate feed. This difference was significant ( p < 0.001). Our results suggest that it is of environmental importance to preserve the lichens on the tundra and minimize supplementary feeding with concentrate diets, in order to reduce methane emission