A LACK OF AVIAN AND MAMMALIAN HAEMATOZOA IN THE ANTARCTIC AND CANADIAN ARCTIC

1961 ◽  
Vol 39 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Marshall Laird

Blood films were obtained from 111 animals in New Zealand's Ross Dependency, and 165 on Prince of Wales Island, N.W.T. Most of them were from birds, and all proved negative for haematozoa although not because of any lack of susceptibility. An absence of vectors precludes local transmission in the areas sampled, and while wide-ranging migratory birds nesting in the Arctic could be exposed to infection elsewhere, many of them are normally protected from this hazard by ecological barriers.

2020 ◽  
Vol 47 (2) ◽  
pp. 286-301
Author(s):  
Philip Stone

The Royal Navy surgeon Robert McCormick (1800–1890) took part in three mid-nineteenth century British Polar expeditions, two to the Arctic and one to the Antarctic. Of the two Arctic voyages, the first was to Spitsbergen (in today's Svalbard) in 1827; the second from 1852 to 1853, was one of the expeditions dispatched to search for the missing ships commanded by Sir John Franklin that had set out in 1845 to navigate a “Northwest Passage” through the islands of the Canadian Arctic. The Svalbard expedition was formative in developing McCormick's interest in the Polar regions, with the likely highlight of his career being his subsequent participation in the Antarctic expedition of 1839–1843 led by James Clark Ross. Throughout these expeditions, McCormick collected natural history specimens, principally in the fields of ornithology and geology. Many of the geological specimens he retained in a personal collection which passed to what is now the Natural History Museum, London, on his death in 1890. This collection includes rock specimens from Svalbard and Baffin Bay, and a substantial number of Silurian fossils (mostly brachiopods) from Beechey Island and Devon Island in the Canadian Arctic. The fossil collection was the largest of several assembled during the successive expeditions sent out in search of Franklin, but is one of those that has received no subsequent attention. That omission was largely due to McCormick's own scientific shortcomings and persisted despite his determined efforts to promote himself as a serious scientific naturalist and Arctic authority.


Polar Record ◽  
1961 ◽  
Vol 10 (67) ◽  
pp. 365-371
Author(s):  
T. A. Harwood

In 1946 the United States Weather Bureau and the Canadian Meteorological Service installed the first of the Joint Arctic Weather Stations at Resolute Bay. The network of satellite stations was extended into the Arctic archipelago in the following years on roughly a 275-mile spacing to Mould Bay, Isachsen, Eureka and Alert.


2011 ◽  
Vol 78 (2) ◽  
pp. 549-559 ◽  
Author(s):  
Thibault Varin ◽  
Connie Lovejoy ◽  
Anne D. Jungblut ◽  
Warwick F. Vincent ◽  
Jacques Corbeil

ABSTRACTPolar and alpine microbial communities experience a variety of environmental stresses, including perennial cold and freezing; however, knowledge of genomic responses to such conditions is still rudimentary. We analyzed the metagenomes of cyanobacterial mats from Arctic and Antarctic ice shelves, using high-throughput pyrosequencing to test the hypotheses that consortia from these extreme polar habitats were similar in terms of major phyla and subphyla and consequently in their potential responses to environmental stresses. Statistical comparisons of the protein-coding genes showed similarities between the mats from the two poles, with the majority of genes derived fromProteobacteriaandCyanobacteria; however, the relative proportions differed, with cyanobacterial genes more prevalent in the Antarctic mat metagenome. Other differences included a higher representation ofActinobacteriaandAlphaproteobacteriain the Arctic metagenomes, which may reflect the greater access to diasporas from both adjacent ice-free lands and the open ocean. Genes coding for functional responses to environmental stress (exopolysaccharides, cold shock proteins, and membrane modifications) were found in all of the metagenomes. However, in keeping with the greater exposure of the Arctic to long-range pollutants, sequences assigned to copper homeostasis genes were statistically (30%) more abundant in the Arctic samples. In contrast, more reads matching the sigma B genes were identified in the Antarctic mat, likely reflecting the more severe osmotic stress during freeze-up of the Antarctic ponds. This study underscores the presence of diverse mechanisms of adaptation to cold and other stresses in polar mats, consistent with the proportional representation of major bacterial groups.


2011 ◽  
Vol 7 (6) ◽  
pp. 833-835 ◽  
Author(s):  
Raymond H. G. Klaassen ◽  
Thomas Alerstam ◽  
Peter Carlsson ◽  
James W. Fox ◽  
Åke Lindström

Migratory land birds perform extreme endurance flights when crossing ecological barriers, such as deserts, oceans and ice-caps. When travelling over benign areas, birds are expected to migrate by shorter flight steps, since carrying the heavy fuel loads needed for long non-stop flights comes at considerable cost. Here, we show that great snipes Gallinago media made long and fast non-stop flights (4300–6800 km in 48–96 h), not only over deserts and seas but also over wide areas of suitable habitats, which represents a previously unknown migration strategy among land birds. Furthermore, the great snipes achieved very high ground speeds (15–27 m s −1 ), which was not an effect of strong tailwind support, and we know of no other animal that travels this rapidly over such a long distance. Our results demonstrate that some migratory birds are prepared to accept extreme costs of strenuous exercise and large fuel loads, even when stopover sites are available along the route and there is little tailwind assistance. A strategy of storing a lot of energy before departure, even if migration is over benign habitats, may be advantageous owing to differential conditions of fuel deposition, predation or infection risk along the migration route.


2007 ◽  
Vol 59 (2) ◽  
pp. 366-376 ◽  
Author(s):  
Katia Comte ◽  
Marie Å Abacká ◽  
Alyssa Carré-Mlouka ◽  
Josef Elster ◽  
Jiří Komárek

2014 ◽  
Vol 11 (2) ◽  
pp. 293-308 ◽  
Author(s):  
E. E. Popova ◽  
A. Yool ◽  
Y. Aksenov ◽  
A. C. Coward ◽  
T. R. Anderson

Abstract. The Arctic Ocean is a region that is particularly vulnerable to the impact of ocean acidification driven by rising atmospheric CO2, with potentially negative consequences for calcifying organisms such as coccolithophorids and foraminiferans. In this study, we use an ocean-only general circulation model, with embedded biogeochemistry and a comprehensive description of the ocean carbon cycle, to study the response of pH and saturation states of calcite and aragonite to rising atmospheric pCO2 and changing climate in the Arctic Ocean. Particular attention is paid to the strong regional variability within the Arctic, and, for comparison, simulation results are contrasted with those for the global ocean. Simulations were run to year 2099 using the RCP8.5 (an Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) scenario with the highest concentrations of atmospheric CO2). The separate impacts of the direct increase in atmospheric CO2 and indirect effects via impact of climate change (changing temperature, stratification, primary production and freshwater fluxes) were examined by undertaking two simulations, one with the full system and the other in which atmospheric CO2 was prevented from increasing beyond its preindustrial level (year 1860). Results indicate that the impact of climate change, and spatial heterogeneity thereof, plays a strong role in the declines in pH and carbonate saturation (Ω) seen in the Arctic. The central Arctic, Canadian Arctic Archipelago and Baffin Bay show greatest rates of acidification and Ω decline as a result of melting sea ice. In contrast, areas affected by Atlantic inflow including the Greenland Sea and outer shelves of the Barents, Kara and Laptev seas, had minimal decreases in pH and Ω because diminishing ice cover led to greater vertical mixing and primary production. As a consequence, the projected onset of undersaturation in respect to aragonite is highly variable regionally within the Arctic, occurring during the decade of 2000–2010 in the Siberian shelves and Canadian Arctic Archipelago, but as late as the 2080s in the Barents and Norwegian seas. We conclude that, for future projections of acidification and carbonate saturation state in the Arctic, regional variability is significant and needs to be adequately resolved, with particular emphasis on reliable projections of the rates of retreat of the sea ice, which are a major source of uncertainty.


2017 ◽  
Vol 47 (2) ◽  
pp. 164-199
Author(s):  
Adam M. Sowards

Exploration has always centered on claims: for country, for commerce, for character. Claims for useful scientific knowledge also grew out of exploration’s varied activities across space and time. The history of the Canadian Arctic Expedition of 1913–18 exposes the complicated process of claim-making. The expedition operated in and made claims on many spaces, both material and rhetorical, or, put differently, in several natural and discursive spaces. In making claims for science, the explorer-scientists navigated competing demands on their commitments and activities from their own predilections and from external forces. Incorporating Arctic spaces into the Canadian polity had become a high priority during the era when the CAE traversed the Arctic. Science through exploration—practices on the ground and especially through scientific and popular discourse—facilitated this integration. So, claiming space was something done on the ground, through professional literature, and within popular narratives—and not always for the same ends. The resulting narrative tensions reveal the messy material, political, and rhetorical spaces where humans do science. This article demonstrates how explorer-scientists claimed material and discursive spaces to establish and solidify their scientific authority. When the CAE claimed its spaces in nature, nation, and narrative, it refracted a reciprocal process whereby the demands of environment, state, and discourse also claimed the CAE.


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