MARMAM Members,
On behalf of my co-authors and myself, I am pleased to share our new paper,
titled “Pacific walrus diet across 4000 years of changing sea ice conditions”,
recently published in Quaternary Research. The paper is available here:
https://goo.gl/SSKbqY <https://goo.gl/SSKbqY>
Clark, C.T., L. Horstmann, A. de Vernal, A.M. Jensen, and N. Misarti. 2019.
Pacific walrus diet across 4000 years of changing sea ice conditions.
Quaternary Research. 1–17. doi:10.1017/qua.2018.140
Declining sea ice is expected to change the Arctic’s physical and
biological systems in ways that are difficult to predict. This study used
stable isotope compositions (δ13C and δ15N) of archaeological, historic, and
modern Pacific walrus (Odobenus rosmarus divergens) bone collagen to
investigate the impacts of changing sea ice conditions on walrus diet during
the last ∼4000 yr. An index of past sea ice conditions was generated using
dinocyst-based reconstructions from three locations in the northeastern Chukchi
Sea. Archaeological walrus samples were assigned to intervals of high and low
sea ice, and δ13C and δ15N were compared across ice states. Mean δ13C and δ15N
values were similar for archaeological walruses from intervals of high and low
sea ice; however, variability among walruses was greater during low-ice
intervals, possibly indicating decreased availability of preferred prey.
Overall, sea ice conditions were not a primary driver of changes in walrus
diet. The diet of modern walruses was not consistent with archaeological low
sea ice intervals. Rather, the low average trophic position of modern walruses
(primarily driven by males), with little variability among individuals,
suggests that trophic changes to this Arctic ecosystem are still underway or
are unprecedented in the last ∼4000 yr.
I am happy to provide a PDF of the article upon request. Please email me at
[email protected] <mailto:[email protected]> if you are interested, or if you
have any questions about the paper.
Best regards,
Casey Clark
CFOS/WERC
University of Alaska Fairbanks
[email protected] <mailto:[email protected]>_______________________________________________
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