faculty listing

A Photo of  Lara Horstmann-Dehn

Contact Information

Institute of Marine Science
232 Irving II
P.O. Box 757220
University of Alaska Fairbanks
Fairbanks, AK 99775-7220
Phone: (907) 474-7724
Fax: (907) 474-7204
lara.horstmann@alaska.edu

Lara Horstmann-Dehn Assistant Professor

Fisheries Ecology • Marine Biology • Marine Mammals

Education

  • M.S. 1997 University of Kiel (Zoology)
  • Ph.D. 2005 University of Alaska Fairbanks (Biology)

Office Hours

Tuesday and Thursday 11:30-13:00

Research Overview

I am interested in broad-scale marine mammal ecology. Feeding ecology in particular is a keystone piece of information to understand adaptation potential of marine mammals and challenges that may arise. Dietary limitations can affect reproductive success, compromise immune function, change exposure to new pathogens (i.e., parasites, contaminants), and can therefore not only limit marine mammal population growth, but also potentially introduce new threats to humans depending on them as a subsistence resource.

I focus my research on Arctic marine mammals, because 1) they are of cultural and nutritional importance to subsistence users, 2) the Arctic is undergoing noticeable change, and 3) planned oil and gas development in this habitat

I am also working on a fish parasite, Ichthyophonus hoferi, in Chinook salmon, and its potential impact on pre-spawning mortality and fecundity

Current Research Projects

  • Evaluation of Chinook Salmon Mortality Factors in Alaska
  • WALRUS–Walrus Adaptability and Long-term Responses; Using multi-proxy data to project Sustainability
  • Freshwater growth and survival in AYK Chinook salmon: maternal influences, predation mortality, and the ultimate effects on stock productivity
  • Bowhead whale feeding in the western Beaufort Sea (BOWFEST)
  • Tracking the seasonal contribution of algal fatty acids to the arctic marine system
  • Trophic links of forage fishes and ice seals in the Chukchi Sea

Publications

Seymour, J., Horstmann-Dehn, L., Wooller, M. (2014): Proportion of higher trophic-level prey in the diet of Pacific walruses (Odobenus rosmarus divergens). Polar Biology. doi:10.1007/s00300-014-1492-z

Seymour, J., Horstmann-Dehn, L., Wooller, M. (2014): Inter-annual variability in the proportional contribution of higher trophic levels to the diet of Pacific walruses. Polar Biology DOI: 10.1007/s00300-014-1460-7

Seymour, J., Horstmann-Dehn, L., Rosa, C., Lopez, A. (2014): Occurrence and genotypic analysis of Trichinella in Alaskan marine-associated mammals of the Bering and Chukchi seas. Veterinary Parasitology 200:153-164 .

Carroll, S.S., Horstmann-Dehn, L., Norcross, B.L. 2013. Diet history of ice seals using stable isotope ratios in claw growth bands. Canadian Journal of Zoology 91: 191-202.

Horstmann-Dehn, L., Follmann, E.H., Rosa, C., Zelensky, G., George, C. 2012. Stable carbon and nitrogen isotope ratios in muscle and epidermis of Arctic whales. Marine Mammal Science 28: E173–E190.

George, J.C., Follmann, E., Zeh, J., Sousa, M., Tarpley, R., Suydamn, R., Horstmann-Dehn, L. 2011. A new way to estimate the age of bowhead whales (Balaena mysticetus) using ovarian corpora counts. Canadian Journal of Zoology 89: 840-852.

Rosa, C., Blake, J.E., Bratton, G.R., Dehn, L-A., Gray, M.J., O’Hara, T.M. 2008. Heavy metal and mineral concentrations and their relationship to histopathological findings in the bowhead whale (Balaena mysticetus). Science of the Total Environment 399: 165-178.

George, J.C., Wetzel, D., O’Hara, T.M., Robertson, K., Dehn, L., Leduc, R., Reynolds, J. 2008. An analysis of ancient bowhead mangtak from Gambell Alaska: What can it tell us? SC/60/E2. 60th Meeting of the International Whaling Commission, Scientific Committee.

Kahler, E., Burton, T., Hamazaki, T., Borba, B.M., Jasper, J., Dehn, L.-A. (2007): Assessment of Ichthyophonus in Chinook salmon within the Yukon River Drainage, 2004. Alaska Department of Fish and Game, Fishery Data Series No. 07-64, Anchorage.

Dehn, L.-A., Sheffield, G. G., Follmann, E. H., Duffy, L. K., Thomas, D. L., O’Hara, T. M. (2007): Feeding ecology of phocid seals and some walrus in the Alaskan and Canadian Arctic as determined by stomach contents and stable isotope analysis. Polar Biology 30, 167-181.

Dehn, L.-A., Follmann, E. H., Thomas, D. L., Sheffield, G. G., Rosa, C., Duffy, L. K., O’Hara, T. M. (2006): Trophic relationships in an Arctic food web and implications for trace metal transfer. Science of the Total Environment 362, 103-123.

Dehn, L.-A., Follmann, E. H., Rosa, C., Duffy, L. K., Thomas, D. L., Bratton, G. R., Taylor, R. J., O’Hara, T. M. (2006): Stable isotope and trace element status of subsistence-hunted bowhead and beluga whales in Alaska and gray whales in Chukotka. Marine Pollution Bulletin 52, 301-319.

Hughes-Hanks, J. M., Rickard, L. G., Panuska, C., Saucier, J. R., O’Hara, T. M., Dehn, L., Rolland, R. M. (2005): Prevalence of Cryptosporidium spp. and Giardia spp. in five marine mammal species. Journal of Parasitology 91, 1225-1228.

Dehn, L.-A., Sheffield, G. G., Follmann, E. H., Duffy, L. K., Thomas, D. L., Bratton, G. R., Taylor, R. J., O’Hara, T. M. (2005): Trace elements in tissues of phocid seals harvested in the Alaskan and Canadian Arctic – Influence of age and feeding ecology. Canadian Journal of Zoology 83, 726-746.

O’Hara, T. M., Hoekstra, P., Rosa, C., Dehn, L.-A., Woshner, V., Wise, J., Ylitalo, G., Wetzel, D., Bratton, G. (2004): Bowhead whale contaminants: A review of current state of knowledge and possible future directions. SC/56/E1. 56th Meeting of the International Whaling Commission (IWC SC).

Hoekstra, P. F., Dehn, L.-A., George, J. C., Muir, D. C. G., and O’Hara, T. M (2002): Trophic ecology of bowhead whales (Balaena mysticetus) compared with that of other arctic marine biota as interpreted from carbon-, nitrogen-, and sulfur-isotope signatures. Canadian Journal of Zoology 80, 223-231.