Polar Research (E-Journal)
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Decrease of lichens in Arctic ecosystems: the role of wildfire, caribou, reindeer, competition and climate in north-western Alaska
No full textWe review and present a synthesis of the existing research dealing with changing Arctic tundra ecosystems, in relation to caribou and reindeer winter ranges. Whereas pan-Arctic studies have documented the effects on tundra vegetation from simulated climate change, we draw upon recent long-term regional studies in Alaska that have documented the actual, on-the-ground effects. Our review reveals signs of marked change in Arctic tundra ecosystems. Factors known to be affecting these changes include wildfire, disturbance by caribou and reindeer, differential growth responses of vascular plants and lichens, and associated competition under climate warming scenarios. These factors are interrelated, and, we posit, unidirectional: that is, they are all implicated in the significant reduction of terricolous lichen ground cover and biomass during recent decades. Lichens constitute the primary winter forage for large, migratory caribou and reindeer herds, which in turn are a critical subsistence resource for rural residents in Alaska. Thus, declines in these lichens are a major concern for rural people who harvest caribou and reindeer for subsistence, as well as for sport hunters, reindeer herders, wildlife enthusiasts and land managers. We believe a more widely distributed and better integrated research programme is warranted to quantify the magnitude and extent of the decline in lichen communities across the Arctic
A reindeer herder’s perspective on caribou, weather and socio-economic change on the Seward Peninsula, Alaska
No full textNon-climate variables shape vulnerability and adaptive capacity to climate change. Here, we describe how recent environmental and socio-economic developments have transformed reindeer herding and perceptions of weather on the Seward Peninsula, Alaska. The reindeer industry has shrunk considerably since the early 1990s, when the winter range of the Western Arctic Caribou Herd expanded, and over 17 000 reindeer mixed with migrating caribou and left the region. Socio-economic and environmental repercussions make the continuation of herding tenuous, and erode the ability of herders to cope with weather variability, among other perturbations. We present a case study of one herder’s annual cycle, and juxtapose physical drivers of herding activities, including weather-station and herder observations of local weather variability, with socio-economic factors. There is an increased urgency to access and monitor reindeer with caribou present, but herding plans are constrained by lower economic returns and the need to spend more time in non-herding jobs. Although weather is a greater concern now for immediate herd access, standard weather data are largely irrelevant to the mechanics of herding, whereas variables pertaining to the timing of biotic events (e.g., synchrony of spring break-up and calving) and visibility are attributed to lost herding opportunities. Short-term responses to weather conditions stem from more longterm vulnerability associated with caribou presence, reduced herd size, difficulties affording snowmobile maintenance or crew assistance, and dwindling market opportunities. We emphasize the environmental and socioeconomic interactions that affect vulnerability and adaptive capacity for modern herding
Stable isotope food-web analysis and mercury biomagnification in polar bears (Ursus maritimus)
No full textMercury (Hg) biomagnification occurs in many ecosystems, resulting in a greater potential for toxicological effects in higher-level trophic feeders. However, Hg transport pathways through different food-web channels are not well known, particularly in high-latitude systems affected by the atmospheric Hg deposition associated with snow and ice. Here, we report on stable carbon and nitrogen isotope ratios, and Hg concentrations, determined for 26, late 19th and early 20th century, polar bear (Ursus maritimus) hair specimens, collected from catalogued museum collections. These data elucidate relationships between the high-latitude marine food-web structure and Hg concentrations in polar bears. The carbon isotope compositions of polar bear hairs suggest that polar bears derive nutrition from coupled food-web channels, based in pelagic and sympagic primary producers, whereas the nitrogen isotope compositions indicate that polar bears occupy > fourth-level trophic positions. Our results show a positive correlation between polar bear hair Hg concentrations and d15N. Interpretation of the stable isotope data in combination with Hg concentrations tentatively suggests that polar bears participating in predominantly pelagic food webs exhibit higher mercury concentrations than polar bears participating in predominantly sympagic food webs
Further to the death of Sigurd B. Myhre at Camp Abruzzi, Rudolf Island, Franz Josef Land, during the Ziegler Polar Expedition, 16 May 1904
No full textIn the spring of 1904, during the Ziegler Polar Expedition led by Anthony Fiala, Sigurd B. Myhre, a Norwegian from Trondheim who served on-board the expedition ship America as a fireman, fell ill and died. The papers of Dr George Shorkley, surgeon to the Ziegler Polar Expedition, contain hints that Myhre may have died from causes other than natural causes
Foreword to the special issue: climate change impacts, adaptation and vulnerability in the Arctic
No full textThe Arctic climate is changing, carrying wide-ranging implications for indigenous and non-indigenous inhabitants, businesses, industry and government across the circumpolar region. The latest scientific assessments indicate that change is happening faster than previously thought, and that the Arctic will continue to experience dramatic climate change in the future. This special edition of Polar Research brings together nine papers on climate change impacts, adaptation and vulnerability in the Arctic, providing important insights on the nature of the risks and opportunities posed by climate change in the circumpolar region, highlighting opportunities for policy response and providing insights on how to conduct effective climate change research with Arctic communities
Foraminiferal morphogroups in dysoxic shelf deposits from the Jurassic of Spitsbergen
No full textAnalysis of benthic foraminiferal assemblages was performed in Bathonian to Kimmeridgian deposits through a section covering the lower half of the Agardhfjellet Formation in central Spitsbergen. The section consists mainly of organic-rich shales, which contain low-diversity agglutinated assemblages. In this foraminiferal succession five morphogroups were differentiated according to shell architecture (general shape, mode of coiling and number of chambers), integrated with the supposed microhabitat (epifaunal, shallow infaunal and deep infaunal) and feeding strategy (suspension-feeder, herbivore, bacterivore, etc.). The environmental evolution of the analysed section is interpreted by using the stratigraphic distribution of morphogroups, combined with species diversities and sedimentary data, in a sequence stratigraphic framework. The section comprises two depositional sequences, which demonstrate that species diversity and relative frequency of morphogroups are correlative with transgressive–regressive trends controlling depth and oxygenation of the water column. In both sequences, the maximum flooding interval is characterized by increased organic carbon content, dominance of the epifaunal morphogroups and reduced species diversity: features reflecting the increased degree of stagnation separating the transgressive phase from the regressive phase
Review of Plants at the margin. Ecological limits and climate change
No full textProfessor Crawford does it again! It was a great privilege to be asked to review Professor Crawford’s latest book, Plants at the margin, and I did so with immense pleasure. It is a hefty tome, a full 478 pages, but is easy to read and richly illustrated with figures, tables and maps, as well as many photographs from Crawford’s own expeditions. Crawford draws on his own extensive field experience, and his love of the Arctic clearly shines through, with examples from Svalbard, Greenland, Iceland, Ellesmere Island, Siberia and northern Scandinavia
Review of How Peary reached the pole: the personal story of his assistant, by Donald B. MacMillan
No full textThis beautifully produced reprint edition of Donald B. MacMillan’s 1934 paean to his mentor Robert E. Peary arrives just in time for the centennial of Peary’s claim to have reached the geographic North Pole on 6 April 1909. As the writers of the concise introduction point out, it also arrives in the middle of a growing international focus on how climate change is altering both the environment of the Arctic and the human responses to this change. It could even be argued that there is more sustained attention being paid to the High North at this moment than at any time since Peary’s famous feud with fellow American claimant to the North Pole, Frederick A. Cook
Review of Nuussuarmiut—hunting families on the big headland. Meddelelser om Grønland: Man & Society 35, by Keld Hansen
No full textNuussuarmiut is based on research conducted by the author from 1966 to 1968 in the community of Nuussuaq, in the Upernavik District, West Greenland. As Hansen explains in a much appreciated Introduction cum prologue, his career interest at the time he began this fieldwork was in material culture. This is amply evidenced by the numerous, highly detailed sketches and scale drawings that, along with archival and the author’s own photographs, are integral to almost every chapter
Antarctic ascidians: an isolated and homogeneous fauna
No full textSeveral biogeographical studies have already been performed on the ascidians of the Antarctic region. However, new data obtained in the last few years have led us to a revision of the biogeography of this fauna. To examine the biogeographical structure of the Antarctic region, we divided it into 10 sectors, depending on the principal geographical features, and then applied cluster analysis and a multi-dimensional scaling ordination to a presence/absence matrix of species for each biogeographical area. Our study shows that Antarctic ascidians are a very homogeneous fauna, with a high level of endemism in the whole region (25–51% of Antarctic endemic species per sector), but with a low percentage of sector endemism (only up to 10%). This probably results from isolation arising from the Antarctic Convergence, and the vast geographical distances from adjacent regions, as well as from the relative constancy of the hydrographical conditions and the dispersal of organisms through circumpolar currents. In fact, cosmopolitan species represented only 0–7% of the total ascidian fauna in all sectors. Only the Bellingshausen Sea (low sample size), Bouvetøya (young and isolated, with an impoverished ascidian fauna) and the South Sandwich Islands (also young and isolated) are relatively separated. The insular sectors were more closely related to the South America and sub- Antarctic regions than the continental ones, showing a latitudinal gradient