scholarly journals Abundance of Atlantic walrus in Western Nares Strait, Baffin Bay Stock, during summer

2014 ◽  
Vol 9 ◽  
pp. 123 ◽  
Author(s):  
Robert EA Stewart ◽  
Erik W Born ◽  
Rune Dietz ◽  
Mads Peter Heide-Jørgensen ◽  
Frank Farsø Rigét ◽  
...  
Keyword(s):  
Water Surface ◽  
Open Water ◽  
Ellesmere Island ◽  
Baffin Bay ◽  
Nares Strait ◽  
The North ◽  
North Water Polynya ◽  
Odobenus Rosmarus ◽  
North Water ◽  
Odobenus Rosmarus Rosmarus

Atlantic walruses (Odobenus rosmarus rosmarus) belonging to the Baffin Bay subpopulation occur year round in the North Water polynya (NOW) between NW Greenland and eastern Ellesmere Island (Canada). They are hunted for subsistence purposes by residents of the Qaanaaq area (NW Greenland) bordering the NOW to the east and by Canadian Inuit at the entrance to Jones Sound in Nunavut. During the open-water period NW Greenland is virtually devoid of walruses which concentrate along eastern and southern Ellesmere Island at this time of the year. To determine the abundance of walruses in the NOW area, aerial surveys were conducted in August of 1999, 2008, and 2009. In July 2009, nine satellite-linked transmitters were deployed in nearby Kane Basin. Surveys on 9 and 20 August 2009 along eastern Ellesmere Island were the most extensive and were augmented with concomitant data on haul-out and at water surface activity from three (1 F, 2 M) of the nine tags that were still functioning. We therefore focus on the 2009 surveys. Walruses were observed on the ice and in water primarily in Buchanan Bay and Princess Marie Bay where the remaining functional tags were located. The Minimum Counted population (MCP) was 571 on 20 August. Adjusting the MCP of walruses on ice for those not hauled out, the estimate of abundance of walruses in the Baffin Bay stock was 1,251(CV=1.00, 95% CI = 1,226) when adjusted by the proportion of tags ‘dry’ at the time of the survey and 1,249 (CV=1.12, 95% CI = 1,370) when adjusted by the average time tags were dry. The surveys did not cover all potential walrus summering habitat along eastern Ellesmere Island and are negatively biased to an unknown degree.

Indications of two genetically different subpopulations of Atlantic walruses (Odobenus rosmarus rosmarus) in west and northwest Greenland

2000 ◽  
Vol 78 (11) ◽  
pp. 1999-2009 ◽  
Author(s):  
L W Andersen ◽  
E W Born
Keyword(s):  
Gene Flow ◽  
The North ◽  
North Water Polynya ◽  
Odobenus Rosmarus ◽  
Length Polymorphisms ◽  
North Water ◽  
Nuclear Microsatellite ◽  
Restriction Length ◽  
Mutational Effect ◽  
Odobenus Rosmarus Rosmarus

Analyses of nuclear and mitochondrial DNA in walruses from northwestern Greenland (76°30'-78°30'N; i.e., in the area of the North Water polynya of northern Baffin Bay and Smith Sound) and west-central Greenland ( 67°-68°N) revealed two genetically distinct subpopulations. The studied sample consisted of tissues from 91 Atlantic walruses (Odobenus rosmarus rosmarus) from northwestern Greenland (1989-1990) and 33 Atlantic walruses from western Greenland (1988-1997). The analyses were based upon 12 nuclear microsatellite loci and restriction length polymorphisms observed in the ND1, ND2, and ND3/4 segments of mtDNA. Evolutionary factors creating the observed genetic differences were mainly drift and gene flow, even though a more pronounced mutational effect was observed at the mitochondrial level. Hence, there appears to be some male-mediated gene flow between the two subpopulations, whereas female-mediated gene flow apparently has been restricted for a considerable time. No temporal variation in population structure was detected in the sample from northwestern Greenland. Females collected in the summer season in this area were shown to be philopatric, meaning that closely related females stay and (or) travel together with a mean relatedness value close to the expected relatedness value for half siblings.

scholarly journals Applications of Satellite Thermal Infrared Images for Monitoring North Water during the Periods of Polar Darkness

1980 ◽  
Vol 25 (93) ◽  
pp. 425-438
Author(s):  
B. Dey
Keyword(s):  
Satellite Images ◽  
Open Water ◽  
Thermal Infrared ◽  
Water Area ◽  
Infrared Images ◽  
Baffin Bay ◽  
The North ◽  
Thermal Infrared Images ◽  
North Water

AbstractThe study reported here illustrates the unique value of NOAA thermal infrared (TIR) images for monitoring the North Water area in Smith Sound and northern Baffin Bay during the periods of polar darkness. Wintertime satellite images reveal that, during the months of December through February, open water and thin ice occur in a few leads and polynyas. However, in March, the areas of open water and thin ice decrease to a minimum with a consequent higher concentration of ice. Two ice dams, in northern Kennedy Channel and in northern Smith Sound, regulate the flow of ice into northern Baffin Bay and also determine the areal variations of open water and thin ice in Smith Sound.

Radiogenic Isotope Signatures of Holocene Sediments from Kane Basin: Linkage with the Re-opening and Evolution of Nares Strait

2021 ◽  
Author(s):  
Lina Madaj ◽  
Friedrich Lucassen ◽  
Claude Hillaire-Marcel ◽  
Simone A. Kasemann
Keyword(s):  
Ellesmere Island ◽  
The Arctic ◽  
Baffin Bay ◽  
Low Salinity ◽  
The Core ◽  
The Past ◽  
Nares Strait ◽  
The North ◽  
Sediment Input ◽  
Detrital Sediment

<p>The re-opening of the Arctic Ocean-Baffin Bay gateway through Nares Strait, following the Last Glacial Maximum, has been partly documented, discussed and revised in the past decades. The Nares Strait opening has led to the inception of the modern fast circulation pattern carrying low-salinity Arctic water towards Baffin Bay and further towards the Labrador Sea. This low-salinity water impacts thermohaline conditions in the North Atlantic, thus the Atlantic Meridional Overturning Circulation. Available land-based and marine records set the complete opening between 9 and 7.5 ka BP [1-2], although the precise timing and intensification of the southward flowing currents is still open to debate. A recent study of a marine deglacial sedimentary record from Kane Basin, central Nares Strait, adds information about subsequent paleoceanographic conditions in this widened sector of the strait and proposed the complete opening at ~8.3 ka BP [3].</p><p>We present complementary radiogenic strontium, neodymium and lead isotope data of the siliciclastic detrital sediment fraction of this very record [3] further documenting the timing and pattern of Nares Strait opening from a sediment provenance approach. The data permit to distinguish detrital material from northern Greenland and Ellesmere Island, transported to the core location from both sides of Nares Strait. Throughout the Holocene, the evolution of contributions of these two sources hint to the timing of the ice break-up in Kennedy Channel, north of Kane Basin, which led to the complete opening of Nares Strait [3]. The newly established gateway of material transported to the core location from the north via Kennedy Channel is recorded by increased contribution of northern Ellesmere Island detrital sediment input. This shift from a Greenland (Inglefield Land) dominated sediment input to a northern Ellesmere Island dominated sediment input supports the hypothesis of the newly proposed timing of the complete opening of Nares Strait at 8.3 ka BP [3] and highlights a progressive trend towards modern-like conditions, reached at about 4 ka BP.</p><p>References:</p><p>[1] England (1999) Quaternary Science Reviews, 18(3), 421–456. [2] Jennings et al. (2011) Oceanography, 24(3), 26-41. [3] Georgiadis et al. (2018) Climate of the Past, 14 (12), 1991-2010.</p>

scholarly journals Biomarker characterization of the North Water Polynya, Baffin Bay: Implications for local sea ice and temperature proxies

2021 ◽  
Author(s):  
David J. Harning ◽  
Brooke Holman ◽  
Lineke Woelders ◽  
Anne E. Jennings ◽  
Julio Sepúlveda
Keyword(s):  
Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Baffin Bay ◽  
The North ◽  
North Water Polynya ◽  
Lipid Biomarker ◽  
North Water ◽  
Order Of Magnitude ◽  
Insight Into

Abstract. The North Water Polynya (NOW, Greenlandic Inuit: Pikialasorsuaq), Baffin Bay, is the largest polynya and one of the most productive regions in the Arctic. This area of thin to absent sea ice is a critical moisture source for local ice sheet sustenance and coupled with the inflow of nutrient-rich Arctic Surface Water, supports a diverse community of Arctic fauna and indigenous people. Although paleoceanographic records can provide critical insight into the NOW’s past behavior, it is critical that we fully understand the modern functionality of the paleoceanographic proxies beforehand. In this study, we analyzed lipid biomarkers, including algal highly-branched isoprenoids and sterols for sea ice extent and pelagic productivity, and algal alkenones and archaeal GDGTs for ocean temperature, in a suite of modern surface sediment samples from within and around the NOW. Our data show that all highly-branched isoprenoids exhibit strong correlations with each other and show highest concentrations within the NOW, which suggests a spring/autumn sea ice diatom source rather than a combination of sea ice and open water diatoms as seen elsewhere in the Arctic. Sterols are also highly concentrated in the NOW and exhibit an order of magnitude higher concentration here compared to sites south of the NOW, consistent with the order of magnitude higher primary productivity observed within the NOW relative to surrounding waters in spring/summer months. Finally, our temperature calibrations for alkenones, GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations, but also identify some additional variables that may be important in controlling their local distribution, such as salinity, nutrients, and dissolved oxygen. Collectively, our datasets provide new insight into the utility of these lipid biomarker proxies in high-latitude settings and will help provide a refined perspective on the Holocene development of the NOW with their application in downcore reconstructions.

scholarly journals An Examination of the Non-Formation of the North Water Polynya Ice Arch

2020 ◽  
Vol 12 (17) ◽  
pp. 2712
Author(s):  
Ron F. Vincent
Keyword(s):  
Ice Dynamics ◽  
Nares Strait ◽  
The North ◽  
North Water Polynya ◽  
Tidal Forces ◽  
Warming Climate ◽  
Northern Border ◽  
Key Factor ◽  
North Water ◽  
First Time

The North Water (NOW), situated between Ellesmere Island and Greenland in northern Baffin Bay, is the largest recurring polynya in the Canadian Arctic. Historically, the northern border of the NOW is defined by an ice arch that forms annually in Kane Basin, which is part of the Nares Strait system. In 2007 the NOW ice arch failed to consolidate for the first time since observations began in the 1950s. The non-formation of the NOW ice arch occurred again in 2009, 2010, 2017 and 2019. Satellite Advanced Very High Resolution Radiometry data shows that large floes broke off from the normally stable landfast ice in Kane Basin for each of these years, impeding ice arch formation. A closer analysis of a 2019 event, in which 2500 km2 of ice sheared away from Kane Basin, indicates that significant tidal forces played a role. The evidence suggests that thinning ice from a warming climate combined with large amplitude tides is a key factor in the changing ice dynamics of the NOW region. The non-formation of the NOW ice arch results in an increased loss of multiyear ice through Nares Strait.

scholarly journals Late Holocene sea-surface changes in the North Water polynya reveal freshening of northern Baffin Bay in the 21st century

2021 ◽  
pp. 103642
Author(s):  
Kelsey Koerner ◽  
Audrey Limoges ◽  
Nicolas Van Nieuwenhove ◽  
Thomas Richerol ◽  
Guillaume Massé ◽  
...  
Keyword(s):  
21St Century ◽  
Late Holocene ◽  
Sea Surface ◽  
Baffin Bay ◽  
The North ◽  
North Water Polynya ◽  
North Water ◽  
Surface Changes
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