High Arctic Islands Research Articles

First contribution to the diatom flora of High Arctic Hopen Island (Svalbard)

First contribution to the diatom flora of High Arctic Hopen Island (Svalbard)

Modelling the influence of glacial isostasy on Late Weichselian ice-sheet growth in the Barents Sea

A fully integrated ice-sheet and glacio-isostatic numerical model was run in order to investigate the crustal response to ice loading during the Late Weichselian glaciation of the Barents Sea. The model was used to examine the hypothesis that relative reductions in water depth, caused by glacio-isostatic uplift, may have aided ice growth from Scandinavia and High Arctic island archipelagos into the Barents Sea during the last glacial. Two experiments were designed in which the bedrock response to ice loading was examined: (i) complete and rapid glaciation of the Barents Sea when iceberg calving is curtailed except at the continental margin, and (ii) staged growth of ice in which ice sheets are allowed to ground at different water depths. Model results predict that glacially generated isostatic uplift, caused by an isostatic forebulge from loads on Scandinavia, Svalbard and other island archipelagos, affected the central Barents Sea during the early phase of glaciation. Isostatic uplift, combined with global sea-level fall, is predicted to have reduced sea level in parts of the central Barents Sea by up to 200 m. This reduction would have been sufficient to raise the sea floor of the Central Bank into a subaerial position. Such sea-floor emergence is conducive to the initiation of grounded ice growth in the central Barents Sea. The model indicates that, prior to its glaciation, the depth of the Central Deep would have been reduced from around 400 m to 200 m. Such uplift aided the migration of grounded ice from the central Barents Sea and Scandinavia into the Central Deep. We conclude that ice loading over Scandinavia and Arctic island archipelagos during the first stages of the Late Weichselian may have caused uplift within the central Barents Sea and aided the growth of ice across the entire Barents Shelf. Copyright © 2000 John Wiley & Sons, Ltd.

Setting preferences of Arctic tourists: A study of some assumptions in the recreation opportunity spectrum framework from the Svalbard Archipelago

The substantial growth of polar tourism creates new needs for land-use planning and recreation management. One possible avenue for planning in the high arctic islands of Svalbard involves using the Recreation Opportunity Spectrum (ROS) - a framework for recreation management largely developed and applied within North American settings and management culture. The growing international interest in the use of the framework calls for further testing of the assumptions underlying the ROS concept in cultures outside North America. This study examines the perceptions of environmental setting attributes and dimensions among an international group of recreationists in a wilderness type of setting in the Norwegian Arctic. The study raises the question whether the users perceive the recreational setting as a multidimensional phenomenon and whether the setting dimensions identified are congruent with the physical, social and managerial dimensions commonly applied in the ROS framework. Seven dimensions of the recreational setting were identified and labelled naturalness, remoteness, observing traffic, culture, transport, huts and information. The setting dimensions to some extent reflect a ROS type structure, but the results indicate that a site-specific identification of perceived setting dimensions might be more useful for local planning.

Glaciers in the High Arctic and recent environmental change

High Arctic climate change over the last few hundred years includes the relatively cool Little Ice Age (LIA), followed by warming over the last hundred years or so. Meteorological data from the Eurasian High Arctic (Svalbard, Franz Josef Land, Severnaya Zemlya) and Canadian High Arctic islands are scarce before the mid-20th century, but longer records from Svalbard and Greenland show warming from about 1910-1920. Logs of Royal Navy ships in the Canadian Northwest Passage in the 1850s indicate temperatures cooler by 1-2.5 °C during the LIA. Other evidence of recent trends in High Arctic temperatures and precipitation is derived from ice cores, which show cooler temperatures (by 2-3 °C) for several hundred years before 1900, with high interdecadal variability. The proportion of melt layers in ice cores has also risen over the last 70-130 years, indicating warming. There is widespread geological evidence of glacier retreat in the High Arctic since about the turn of the century linked to the end of the LIA. An exception is the rapid advance of some surge-type ice masses. Mass balance measurements on ice caps in Arctic Canada, Svalbard and Severnaya Zemlya since 1950 show either negative or near-zero net balances, suggesting glacier response to recent climate warming. Glacier-climate links are modelled using an energy balance approach to predict glacier response to possible future climate warming, and cooler LIA temperatures. For Spitsbergen glaciers, a negative shift in mass balance of about 0.5 m a-1is predicted for a 1 °C warming. A cooling of about 0.6 °C, or a 23% precipitation increase, would produce an approximately zero net mass balance. A ‘greenhouse-induced’ warming of 1 °C in the High Arctic is predicted to produce a global sea-level rise of 0.063 mm a-1from ice cap melting.

Effects of temperature elevation on a field population of Acyrthosiphon svalbardicum (Hemiptera: Aphididae) on Spitsbergen.

A manipulation experiment was carried out on a field population of the aphid Acyrthosiphon svalbardicum near Ny Ålesund, on the high arctic island of Spitsbergen, using cloches to raise temperature. An average rise in temperature of 2.8 deg. C over the summer season markedly advanced the phenology of both the host plant Dryas octopetala and the aphid. Advanced aphid phenology, with concomitant increases in reproductive output and survival, and successful completion of the life-cycle led to an eleven-fold increase in the number of overwintering eggs. Thermal budget requirements in day degrees above 0°C were calculated for key life-cycle stages of the aphid. Temperature data from Ny Ålesund over the past 23 years were used to calculate thermal budgets for the field site over the same period and these were compared with the requirements of the aphid. Each estimated thermal budget was then adjusted to simulate the effect of a +2, +4, and -2deg. C change in average temperature on aphid performance. This retrospective analysis (i) confirms that the life-cycle of A. svalbardicum is well suited to exploit higher summer temperatures, (ii) indicates that the annual success of local populations are sensitive to small changes in temperature and (iii) suggests that the aphid is living at the limits of its thermal range at Ny Ålesund based on its summer thermal budget requirements.

Effects of age and reproductive status on body composition in Svalbard reindeer

Summary: In continental populations of Rangifer fertility in females is normally both high and relatively constant. The largest recorded va­ riation in annual rate of pregnancy within a single population is less than two-fold (range = 57.0-87.0 %, T. ^ Skogland, pers. comm.). In high arctic island populations, by contrast, fertility is highly variable: annual rates of birth in Svalbard reindeer (R. tarandus platyrhynchus), for example, vary up to eight-fold (range = 9.0-73.3 %, Tyler 1987, see also Tho­ mas 1982). The physiological mechanisms re­ sponsible for changes in fertility in cervids are not known. However, fertility in females is in­ fluenced by both body weight and fat reserves (Dauphine 1976, Leader-Williams and Ricketts 1982, Reimers 1983, Thomas 1982) and in red

Spatial Heterogeneity and Clonal Structure in Arctic Populations of Apomictic Daphnia

Allozymic surveys of obligately parthenogenetic Daphnia pulex from a Canadian high—arctic island revealed high levels of clonal richness in these populations. The present study was conducted to elucidate the underlying spatial patterns of clonal distributions. Three—way G tests of independence indicated significant within—pond spatial and temporal heterogeneity of clones. In addition, spatial autocorrelation analysis indicated significant between—pond patterning of clones,although distributions were patchy. Generally, clones found at low frequencies in a given pond showed restricted distributions, while the most abundant clones were widespread across the island. Principal components analysis revealed that certain clones were distributed differentially in ponds, which varied in size, relative age, and location on the island. The present clonal composition on the island is most likely the result of multiple colonization events during the period of deglaciation. Between—pond clonal distributions are influenced strongly by the probability of passive dispersal of resting eggs (ephippia) via any number of dispersal vectors (e.g., avian, human). Elucidation of the underlying mechanisms that maintain clonal diversity and influence clonal distributions in this Daphnia assemblage requires further study of both deterministic (e.g., selection) and stochastic (i.e., historical) factors.

Arthropods of Alpine Aeolian Ecosystems

The diversity and ubiquity of insects on the planet Earth is a commonplace premise of every entomology textbook. From the tropics to Antarctica, from deserts and hot pools to high arctic islands, and from open ocean to mountain peaks, insects have found unorthodox niches where other arthropods and microorganisms are commonly their sole companions. Their great capacity for dispersal and their relatively small size, which together at least partially explain insect diversity (71), enable them to find and exploit habitats in which they are' protected from macroscale environmental factors. In addition to the benefits of scale, various insects have the physiological capacity to survive ambient temperatures that exclude most Metazoa, salinities that defy most regulatory systems, and/or ability to tolerate deep-freezing and desiccation. Of all the eccentric habitats colonized by insects, perhaps the most extreme are those where the nonnal pattern of energy flow from photosynthetic plants is denied, as in areas of extreme aridity, e.g. deserts (64) and lava fields (47); cold, e.g. alpine (65, 66) and polar regions (39); or dark, e.g. caves (20, 49, 69). These environments, like ocean abysses where dwellers depend on organic material filtering down from the photic zone, are all examples of what Hutchinson (53) termed the allobiosphere, where resident organisms depend for their subsistence on transported energy and nutrients. Swan (92) drew attention to the widespread distribution of such environments in alpine regions and coined the term aeolian for them, thereby explicitly recognizing the role of wind in the transport of nutrients. The emphasis of this review is on alpine communities, but it is not only in

Arctic marine oil spill research

Canada, with its immense arctic and subarctic regions, wants to develop the promising hydro-carbon potential of the Beaufort Sea, the high arctic islands, the eastern arctic and Labrador. Of necessity, Canada has gradually become a world leader in arctic marine oil spill research. Some of this research has been done by the Canadian federal government through AMOP, the Arctic Marine Oilspill Project. There has been joint oil industry/government research, such as the Beaufort Sea Project and the Baffin Island Oil Spill Project. In oil company initiatives, Dome Petroleum has been a leader in the Beaufort Sea region. Finally, a cooperative oil industry organization, the Arctic Petroleum Operators' Association and its research group, the Canadian Offshore Oil Spill Research Association, have made many important studies. Initial efforts aimed to strengthen existing containment and recovery equipment to operate in light ice conditions. When the limits of this technology were rapidly reached, research turned to developing burning techniques, including fireproof booms, in situ burning against ice edges and in spring melt pools, air deployable igniters and portable burners and incinerators. New dispersant technology was developed for aerial application, for cold water dispersion and for solidification. The effects of dispersed oil in the arctic nearshore and onshore environment were assessed. More recently, subsea containment has become an important area of study. Future research will include methods of mechanical recovery of oil in ice, oil/water emulsions in and under ice, and the mechanism of oil migration upward through pack ice.

Birds of Sarcpa Lake, Melville Peninsula, Northwest Territories: Breeding Phenologies, Densities and Biogeography

Forty species of birds were observed during field studies at Sarcpa Lake, Melville Peninsula, N.W.T. during the summers of 1981 and 1982. Evidence of breeding was found for 22 species and the first definite breeding records for the Melville Peninsula were obtained for Glaucous Gull, Pectoral Sandpiper and Semipalmated Sandpiper and Semipalmated Sandpiper. A hybrid pair of gulls (Glaucous x Herring Gull) also nested and this appears to be the first definite North American record of such a hybrid nesting. Fourteen additional breeding species expected to be present, based on maps in Godfrey (1966), were not found. Average breeding bird density (35 pr/sq km) was comparable to that on Bylot Island, but considerably higher than that measured at other High Arctic sites. Neither average breeding bird densities nor phenologies changed appreciably from year to year despite a late spring melt in 1982. In both years birds began their breeding activities as soon as suitable nesting and feeding habitat became available. A biogeographic analysis based on the occurrence of breeding birds at 25 other sites across the Canadian Arctic indicates that the avifauna at Sarcpa Lake is more similar to those of High Arctic island sites than to those of mainland sites, but includes none of the species whose ranges are mainly within the Arctic Archipelago. Key words: arctic biogeography, birds, phenology, nesting density, Melville Peninsula, multivariate analysis

A Southeastern Baffin Thule House with Ruin Island Characteristics

A prehistoric house depression excavated on the southeastern coast of Baffin Island near Lake Harbour belongs stylistically to an early phase of the Thule Period. However, features such as the rectangular shape, interior open-fire kitchens, and initial absence of a sleeping platform are more characteristic of the early High Arctic Ruin Island phase than of developed Thule. This, and additional evidence from Foxe Basin and Frobisher Bay, suggest that a segment of the earliest Thule migration may have split from the main body in Lancaster Sound and, travelling south through Fury and Helca Strait, reached Hudson Strait and the south coast of Baffin Island. This suggestion is in opposition to earlier interpretations of a slow penetration into the more southerly eastern part of the Canadian Archipelago from the northeastern High Arctic.

Polar bear predation of ringed and bearded seals in the land-fast sea ice habitat

Predation of seals by the polar bear, Ursus maritimus, was not significant in the Western Arctic. In the High Central and Eastern Arctic, and along southeastern Baffin Island, bear predation of the subnivean lairs of ringed seals, Phoca hispida, was common. The ice types hunted by bears differed between the High Arctic and southeastern Baffin Island. However, no difference was seen in the proportion of successful kills. There is strong evidence that the bearded seal, Erignathus barbatus, is an important prey species of the polar bear in southeastern Baffin Island. Polar bears mainly kill newborn pups in their birth lairs. The prime breeding habitat of ringed seals located in ice hummock areas is less successfully preyed upon by bears than other ice types. Several factors such as the complexity of birth lairs and possible olfactory confusion might account for this. Seals under 2 years of age are those most frequently killed by bears. Data are presented to show that harvesting these age-classes provides the maximum return of energy to the bear and results in the least harm to the prey population.

A Closer look at the Proposed Late-Wisconsin-Weichselian Arctic Ice Sheet

AbstractThe CLIMAP 18000 years b.p. experiment required reconstructing late-Wisconsin-Weichselian ice sheets. In the Northern Hemisphere, the greatest uncertainty in these reconstructions is the area covered by ice sheets. Two schools of thought exist (Hughes and others, in press). The minimum-ice-sheet school holds that ice sheets originated from present ice caps in the High Arctic islands, but the northern seaward margins of these ice sheets retreated as the southern landward margins advanced. This occurred because northern margins became isolated from sources of precipitation as Arctic seas became permanently ice-covered and the advancing southern margin changed atmospheric circulation patterns. In this view, these ice sheets stay about the same size and migrate southward during an ice age. Northern margins rarely reach sea-level during the later stage of the ice age so no marine portions form and ablation is by melting or sublimation. Marine portions formed only when the ice sheets migrated across shallow seas between the High Arctic islands and the mainland. At the end of the ice age, huge amounts of heat had to be transferred from the tropics to the ice sheets in order to account for late-Wisconsin-Weichselian and Holocene retreat-rates by melting along ice-sheet margins.

A Closer look at the Proposed Late-Wisconsin-Weichselian Arctic Ice Sheet

Abstract The CLIMAP 18000 years b.p. experiment required reconstructing late-Wisconsin-Weichselian ice sheets. In the Northern Hemisphere, the greatest uncertainty in these reconstructions is the area covered by ice sheets. Two schools of thought exist (Hughes and others, in press). The minimum-ice-sheet school holds that ice sheets originated from present ice caps in the High Arctic islands, but the northern seaward margins of these ice sheets retreated as the southern landward margins advanced. This occurred because northern margins became isolated from sources of precipitation as Arctic seas became permanently ice-covered and the advancing southern margin changed atmospheric circulation patterns. In this view, these ice sheets stay about the same size and migrate southward during an ice age. Northern margins rarely reach sea-level during the later stage of the ice age so no marine portions form and ablation is by melting or sublimation. Marine portions formed only when the ice sheets migrated across shallow seas between the High Arctic islands and the mainland. At the end of the ice age, huge amounts of heat had to be transferred from the tropics to the ice sheets in order to account for late-Wisconsin-Weichselian and Holocene retreat-rates by melting along ice-sheet margins.