Data for: Unprecedented shift in Canadian High Arctic polar bear food web unsettles four millennia of stability
Stable carbon (δ13C) and nitrogen (δ15N) isotope analysis was conducted on modern and archaeological polar bear bone collagen from the Canadian Arctic Archipelago to investigate potential changes in polar bear foraging ecology over four millennia. Polar bear δ13C values showed a significant decline...
| Main Authors: | , , , , |
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| Format: | Dataset |
| Language: | unknown |
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2022
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| Subjects: | |
| Online Access: | https://zenodo.org/record/7492950 https://doi.org/10.5061/dryad.g1jwstqv4 |
| Summary: | Stable carbon (δ13C) and nitrogen (δ15N) isotope analysis was conducted on modern and archaeological polar bear bone collagen from the Canadian Arctic Archipelago to investigate potential changes in polar bear foraging ecology over four millennia. Polar bear δ13C values showed a significant decline in the modern samples relative to all archaeological time-bins, indicating a disruption in the sources of production that support the food web, occurring after the Industrial Revolution. The trophic structure, indicated through δ15N, remained unaltered throughout all time periods. The lower δ13C observed in the modern samples indicates a change in the relative importance of pelagic (supported by open-water phytoplankton) over sympagic (supported by sea ice-associated algae) primary production. The consistency in polar bear δ13C through the late Holocene includes climatic shifts such as the Medieval Warm Period (MWP, A.D. 950–1250) and the early stages of the Little Ice Age (LIA, A.D. 1300–1850). These findings suggest that polar bears inhabit a food web that is more pelagic and less sympagic today than it was through the Late Holocene. We suggest that modern, anthropogenic warming has already affected food web structure in the Canadian Arctic Archipelago when modern data are contextualized with a deep time perspective. Funding provided by: Social Sciences and Humanities Research Council of CanadaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000155Award Number: Insight GrantFunding provided by: Canada Research ChairsCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001804Award Number: Ancient bone samples were collected from 35 polar bears from 10 archaeological sites in the region inhabited by the Lancaster Sound polar bear subpopulation. The archaeological samples came from pre-Dorset (N= 10; 4000–2800 BP), Dorset (N= 15; 1500–700 BP), and Thule (N= 10; 700–500 BP) sites, and consisted of several different anatomical elements but each element represented a distinct individual. The ... |
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