Polar Research (E-Journal)
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Overwintering of terrestrial Arctic arthropods: the fauna of Svalbard now and in the future
No full textThere are over 500 species of arthropods recorded from Svalbard. These animals overwinter either within the soil or on the ground surface, and have to tolerate an environment where the ground is frozen for over 9 months each year. Three cold-tolerance strategies have been described from Svalbard invertebrates: freeze avoidance, freeze tolerance and desiccation. Once in a coldtolerant state the animals can be extremely cold tolerant in terms of both minimum exposure temperature and period of exposure. How the overwintering capabilities of these animals will be affected by climate changes during the next 100 years, as predicted by climate models, is not yet known. Four principle factors with an impact on overwintering of the terrestrial arthropod fauna are outlined here: (1) warmer winter temperatures, with an increased frequency of extreme events such as freeze–thaw cycles and surface icing; (2) changes in snow fall and snow lie; (3) pollutant load; and (4) dispersal of invertebrates to Svalbard. Finally, areas where further research is required are highlighted: including the development of controlled multi-season field experiments; effect of freeze–thaw cycles; changes in thickness and distribution of snow lie, with the subsequent effects on duration of the summer period; chill susceptibility of soil arthropods; assessing potential colonizing species and the likelihood of these species becoming established; assessing the effect of gene flow from surrounding populations; interactions between pollution and cold tolerance; anoxia stress; and the genetics of cold tolerance
Guest editorial—the 1959 Antarctic Treaty: reflecting on the 50th anniversary of a landmark agreement
No full textCommemorating a particular anniversary is always an arbitrary affair, an act of whimsy. After all, why acknowledge the 50th anniversary of someone or some event as opposed to the 48th? In terms of birthdays, we tend to celebrate each year as another rite of human passage. However, when it comes to events such as wars and diplomatic encounters, the media and political commentators like more substantial blocks of time: 10th, 25th, 50th, 75th and 100th anniversaries are particularly noteworthy. The year 2009 has proven no different in terms of representing a temporal marker for the 50th anniversary of the signing of the 1959 Antarctic Treaty. In December 2009 a so-called Antarctic Treaty Summit was held in Washington, D.C. to take advantage of not only such a milestone, but also “to highlight lessons learned about international governance ‘with the interests of science and the progress of all mankind’ ” (Antarctic Treaty Summit 2009, emphasis added).por_163 145..14
An observation of the banded structure of the Antarctic Coastal Current at the prime meridian
No full textObservations of three bands of westward flow and two countercurrents, spanning roughly 50 km from the ice-shelf edge in front of the Fimbul Ice Shelf (prime meridian) in Antarctica, are presented. A comparison with a numerical model and the proximity of two of these current cores to the ice shelf suggest that they split from the Antarctic Coastal Current because of the influence of sea ice on the surface drag. A comparison with previous studies suggests that the other core is the current associated with the Antarctic Slope Front. Because the Fimbul ice shelf overhangs the continental shelf, the Antarctic Coastal Current displaces offshore, getting close to the Antarctic Slope Front. The obtained structure is derived from conductivity–temperature–depth geostrophic velocities from February 2005, referenced with detided acoustic Doppler current profiler velocities
Spatial and temporal variability of ice algal production in a 3D ice–ocean model of the Hudson Bay, Hudson Strait and Foxe Basin system
No full textPrimary production, the basic component of the food web and a sink for dissolved inorganic carbon, is a major unknown in Arctic seas, particularly ice algal production, for which detailed and comprehensive studies are often limited in space and time. We present here a simple ice alga model and its coupling with a regional 3D ice–ocean model of the Hudson Bay system (HBS), including Hudson Strait and Foxe Basin, as a first attempt to estimate ice algal production and its potential contribution to the pelagic ecosystem on a regional scale. The ice algal growth rate is forced by sub-ice light and nutrient availability, whereas grazing and ice melt control biomass loss from the underside of the ice. The simulation shows the primary role of sea-ice dynamics on the distribution and production of ice algae with a high spatio-temporal variability in response to the great variability of ice conditions in different parts of the HBS. In addition to favourable light and nutrient conditions, there must be a sufficient time lag between the onset of sufficient light and ice melt to ensure significant ice algal production. This suggests that, in the context of enhanced warming in Arctic and sub-Arctic regions, earlier melt could be more damaging for ice algal production than later freezing. The model also includes a particulate organic matter (POM) variable, fed by ice melting losses to the water column, and shows a large redistribution of the POM produced by the ice ecosystem on a regional scale
Status of the black-legged kittiwake (Rissa tridactyla) breeding population in Greenland, 2008
No full textBased on the intensified survey efforts (since 2003) of Greenlandic breeding colonies of black-legged kittiwake (Rissa tridactyla), the total Greenland breeding population was estimated at roughly 110 000 breeding pairs, constituting about 4% of the total North Atlantic breeding population. This population estimate of black-legged kittiwake is the most reliable and updated estimate hitherto reported for Greenland. The results confirm considerable population declines in many areas of West Greenland. The breeding population of blacklegged kittiwakes in the Qaanaaq area appears healthy, whereas the rest of the west coast has experienced declines, especially the north-western region (in the area from Upernavik to Kangaatsiaq). Exactly when these reductions have occurred is uncertain because of the limited survey effort in the past, but some colonies declined as far back as the mid-1900s, whereas declines of other colonies have occurred since the 1970–80s. East Greenland data from the past are few, but recent aerial surveys confirm that the abundance of breeding kittiwakes on this inaccessible coast is low. The reasons for the West Greenland declines are not documented. Poor feeding conditions and a high hunting pressure, particularly prior to 2002 when the open season was shortened considerably, are possible explanations
Review of Geological history of Greenland—four billion years of Earth evolution, by Niels Henriksen
No full textA translation of the Danish book Grønlands geologiske udvikling, published in 2005, Geological history of Greenland summarizes the results of more than 60 years of geological mapping and investigations in Greenland by the Geological Survey of Denmark and Greenland. This is a beautifully illustrated, large-format volume. The 270 pages provide a stunning visual presentation, with as many as 850 colour illustrations, photographs and maps accompanied by comprehensive captions. Even if the reader has only a very limited knowledge or interest in geology, the many high-quality scenic pictures of Greenlandic landscapes are impressive. Sixty fact boxes explain basic geological concepts and processes. A full glossary of geological terms, as well as suggestions for further reading, is also provided
Review of Marine Mammals of Svalbard, by K. M. Kovacs, I. Gjertz & C. Lydersen
No full textThis slim but elegant volume fi lls a clear need. As the frequency of expeditions and tourist travel to Spitsbergen and the other islands of Svalbard increases, more and more observations of marine mammals are being made, and there has been no single convenient guide to their identifi cation. The book provides common (English, French, German and Norwegian) and scientifi c names, species description and information on distribution, abundance, general ecology, reproduction and life history, diet, exploitation and management, and current status for the polar bear, fi ve species of seals, the walrus, and 12 species of whales and dolphins that can be seen in the waters of Svalbard. High-quality portraits (painted by Pieter Folkens) and photographs are included for each species. The at-sea photographs of cetaceans are especially helpful. The authors have done an outstanding job of summarizing the scattered technical literature on these animals in clear terms understandable by all. This is aided by a glossary of 80 terms. The accounts are packed with interesting details of life history, behavior and ecology usually not encountered in a field guide
Editorial
No full textWith this issue, Polar Research has gone over to a double-column layout more in line with today’s international publication standards. Basic editorial policy remains unchanged
Notes concerning the vegetation on deflation surfaces, Kapp Linnk, Spitsbergen
No full textThe distribution of vascular plants within four sample areas on a deflation surface on a set of raised beach ridges near Kapp LinnC. Spitsbergen. is described. The \,egetation cover and distribution of the different species are related to the wind pattern and microtopography. Details of the distribution and growth characteristics of Dryas octopetala, Saxifraga oppositifolia, and Silerie acaulis in relation to each other. and to the wind and microtopography are discussed