CFOS Students

Casey Clark

Ph.D. Student

Marine Biology
College of Fisheries and Ocean Sciences
139A Irving II
PO Box 757220
Fairbanks, AK 99775-7220
907-474-5939
Education
B.S., M.S.
Publications
Fleming, A.H, C.T. Clark, J. Calambokidis & J. Barlow. 2015. Humpback whale diets respond to variance in ocean climate and ecosystem conditions in the California Current. Global Change Biology. doi: DOI: 10.1111/gcb.13171

Vu, E. T., C. Clark, K. Catelani, N.M. Kellar & J. Calambokidis. 2014. Seasonal blubber testosterone concentrations of male humpback whales (Megaptera novaeangliae). Marine Mammal Science. 31(3):1258-1264.

Thesis
Impacts of Climate Change on Pacific Walruses
Current Research Projects
  • For my doctoral dissertation I am investigating the impacts of climate change on Pacific walruses. Recent declines in Arctic sea ice and previously unrecorded sea ice minima have led to concerns regarding the future health of ice-dependent pinnipeds populations. Pacific walruses rely heavily on sea ice as a platform for giving birth, molting, and resting between foraging bouts, making this species particularly vulnerable to warming climates and reduced sea ice coverage. My research uses stable isotope ratios (?13C and ?15N) in walrus bones, as well as trace element concentrations in walrus teeth, to investigate changes in diet and feeding location across the past 3,000 years. This timeframe encompasses a number of major climatic anomalies including the Roman Warm, the Medieval Warm, and the Little Ice Age, as well as a number of recent regime shifts in the North Pacific and Bering Sea. By investigating how previous episodes of warming and cooling in the Arctic affected walruses, I hope to generate a better understanding of how current and future Arctic warming may impact the walrus population. This work is part of a large, collaborative research project funded by the National Science Foundation and the Bureau of Ocean Energy Management. Other aspects of the project include investigations of steroid hormone concentrations in walrus bones, analyses of modern and ancient DNA, as well as collection and compilation of Traditional Ecological Knowledge about Pacific walruses from members of Alaska Native communities.
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