Prey selection of polar bears in Foxe Basin, NU, Canada: evidence of dietary flexibility in a specialized predator

Ecological flexibility of a species reflects its ability to cope with environmental change. Although polar bears (Ursus maritimus) are experiencing changes in foraging opportunities due to sea ice loss, regional prey availability and environmental conditions will influence the rate and severity of these effects. We examined changes in polar bear diet and the influence of sea ice characteristics in Foxe Basin over an 18-year period. We combined previous fatty acid data from bears harvested from 1999 to 2003 (n = 82) with additional data from 2010 to 2018 (n = 397). Polar bear diets were diverse; however, ringed seal (Pusa hispida) was the primary prey throughout the sample period. Prey contribution varied temporally and spatially, and by intrinsic factors, while the frequency of prey in diets varied over time suggesting that diet estimates reflect the variability in available prey. Bowhead whale (Balaena mysticetus), although still a minor dietary component, has more than doubled in frequency of occurrence in diets in recent years in association with increased scavenging opportunities. Higher dietary levels of beluga whale (Delphinapterus leucas) and harbour seal (Phoca vitulina) were linked to later breakup date suggesting heavier ice conditions may promote access to both prey species. The flexible foraging strategies of bears in Foxe Basin may help mitigate their vulnerability to changes in prey distribution and habitat conditions. Our results provide insights into the importance of alternative and supplemental food sources for polar bears during phenological changes in ice conditions that will likely have consequences to Arctic community structure as warming continues.

New Insights from the Dorset Type Site at Alarniq, Northern Foxe Basin, Arctic Canada: Beach Level Chronology and Site Use

In 2008, four decades since Meldgaard's work at Alarniq—the type site for Dorset culture—Savelle and Dyke returned to resurvey the site. Archaeological investigations continued in 2015 and 2017 as part of the Foxe Basin Archaeological Project, when Howse conducted further surveys, excavated six semi-subterranean dwellings and two associated middens, and tested five additional features. The new site map and radiocarbon sequence have significantly changed our understanding of site use and beach-level chronology at Alarniq. The number of dwellings varies across the beach ridges, suggesting populations fluctuated throughout the site's use (2,700–800 cal BP). However, the new radiocarbon analyses also indicate that dwellings between 14.5 and 21.5 m above sea level are the same general age and that paleodemography at Alarniq is less straightforward than suggested by the number of features per beach ridge. It appears that ideal house construction location is a stronger indicator of the placement of winter houses at the site than proximity to the shoreline. We suggest this is largely related to site seasonality. These new data have significant implications for our understanding of current Dorset artifact typologies that have largely been developed using the material Meldgaard recovered at the site.

The stratigraphic position and the age of the Ordovician organic-rich intervals in the northern Hudson Bay, Hudson Strait, and Foxe basins—evidence from graptolites

Graptolites recovered from the organic-rich intervals, previously named the Boas River Formation in the Upper Ordovician succession on Southampton, Akpatok, and southern Baffin islands provide a reliable age assessment for the Upper Ordovician petroleum source rocks in the northern Hudson Bay, Hudson Strait, and Foxe basins. They are characterised by Anticostia lata and Anticostia hudsoni in the lower Red Head Rapids Formation on Southampton Island; Anticostia decipiens and Rectograptus socialis in the lower Foster Bay Formation on Akpatok Island; and Diplacanthograptus spiniferus and Amplexograptus praetypicalis in the lower Amadjuak Formation on southern Baffin Island. These data suggest that the organic-rich intervals in the northern Hudson Bay and Hudson Strait basins can be correlated to the Dicellograptus anceps and Paraorthograptus pacificus zones of the upper Katian, and the horizon in the Foxe Basin to the Diplacanthograptus spiniferus Zone of the lower Katian. The Boas River Formation is not deemed appropriate to use as it occurs as an organic-rich interbed in different stratigraphic units in different basins; therefore, it is suggested to abandon it as a stratigraphic term.

An Assessment of Marine Reservoir Corrections for Radiocarbon Dates on Walrus from the Foxe Basin Region of Arctic Canada

ABSTRACTArchaeological sites in the Canadian Arctic often contain substantial quantities of marine mammal bones and in some cases completely lack terrestrial mammal bones. A distrust of radiocarbon (14C) dates on marine mammal bones among Arctic archaeologists has caused many sites to be insufficiently dated. The goal of this study was to investigate the marine reservoir effect on Atlantic walrus in the Foxe Basin region of the Canadian Arctic through a two-pronged approach: dating of live-harvested specimens of known age collected prior to AD 1955 and dating of pairs of animal remains (walrus and caribou) from stratigraphically contemporaneous levels within archaeological features. 14C dates on pre-bomb, live-harvested walrus indicate that a ΔR value of 160±50 yr be used in calibrating dates on walrus from this region. These results differed significantly from a similar set of pre-bomb mollusks, which argues against applying mollusk-based corrections to marine mammals. The results of comparative dating of caribou and walrus from archaeological features provided maximum estimates of reservoir ages that were more varied than the directly measured ages. Although about half of inferred ΔR values overlap the museum specimen results, the others indicate that the assumption of contemporaneity does not hold true.

Climate change and sea ice: Shipping in Hudson Bay, Hudson Strait, and Foxe Basin (1980–2016)

The seasonally ice-covered waters of Hudson Bay, James Bay, Foxe Basin, and Hudson Strait (“the study area”) are bordered by 39 communities with a total population of roughly 50,000 people, most of whom are Inuit or Cree. Sea ice is a cornerstone of the environment and culture of the study area but is also the main barrier to shipping traffic, which has been growing in the area. This paper presents a review of sea ice and shipping in the study area and an analysis of shipping accessibility as represented by the timing of breakup, freeze-up, and the open water season in its offshore and local waters. Offshore ice timing was analyzed using passive microwave-based data for 1980–2014; local ice timing near Rankin Inlet, Churchill, Kuujjuarapik/Whapmagoostui, and Salluit was examined using Canadian Ice Service ice charts for 1996–2016. Open water was defined using sea ice concentration thresholds of ≤15% (offshore) or <20% (local) in an attempt to represent accessible conditions for open water shipping vessels. The results for both offshore and local waters display considerable spatial variability. For offshore waters, breakup currently occurs between 17 May and 19 August and freeze-up occurs between 22 October and 30 December, with overall trends (1980–2014) of +0.58 days year–1 towards an earlier breakup, +0.47 days year–1 towards a later freeze-up, and +0.97 days year–1 towards a longer open water season. Also, significant relationships amongst breakup and freeze-up were observed. For local waters, the 1996–2016 average open water season at the four communities varied between 112.7 days (Churchill) and 154.7 days (Kuujjuarapik/Whapmagoostui). Ultimately, shipping accessibility to Rankin Inlet, Churchill, and Salluit appears to be limited by their local ice timing, while accessibility to Kuujjuarapik/Whapmagoostui appears to be limited by ice timing in northeastern Hudson Bay.