Abstract
The objective of this paper is to report on the demography and pathology of 131 Pacific walruses (Odobenus rosmarus divergens), primarily calves, found dead on the northwest coast of Alaska in September 2009. The walrus carcasses extended over approximately 120 km, but most were found where walruses had hauled out for several days on the beach at Icy Cape. The remote location and severe weather made access to the site difficult and limited the number and extent of necropsies. A total of 71 carcasses were examined: nine were necropsied, and 62 were classified externally for age, gender, blubber depth, and other parameters. The most likely causes of death were crushing trauma, particularly of the upper thorax, neck and head, or asphyxiation due to being trampled by larger animals.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Clarke JT, Ferguson MC, Christman CL, Grassia SL, Brower AA, Morse LJ (2011) Chukchi offshore monitoring in drilling area (COMIDA) distribution and relative abundance of marine mammals: aerial surveys. Final Report, OCS Study BOEMRE 2011-06. National Marine Mammal Laboratory, Alaska Fisheries Science Center, NMFS, NOAA, 7600 Sand Point Way NE, F/AKC3, Seattle, WA 98115-6349
Comiso JC (2012) Large decadal decline of the Arctic multiyear ice cover. J Clim 25:1176–1193. doi:10.1175/JCLI-D-11-00113.1
Cooper LW, Ashjian CJ, Smith SL, Codispoti LA, Grebmeier JM (2006) Rapid seasonal sea-ice retreat in the Arctic could be affecting Pacific walrus (Odobenus rosmarus divergens) recruitment. Aquat Mamm 32:98–102
Fay FH (1985) Odobenus rosmarus. Mamm Species 238:1–7
Fay FH, Kelly BP (1980) Mass natural mortality of walruses (Odobenus rosmarus) at St. Lawrence Island, Bering Sea, autumn 1978. Arct 33:226–245
Fay FH, Kelly BP (1989) Development of a method for monitoring the productivity, survivorship, and recruitment of the Pacific walrus population. Final Report, OCSEAP Study MMS 89-0012. Minerals Management Service, Anchorage, Alaska
Fischbach AS, Monson DH, Jay CV (2009) Enumeration of Pacific walrus carcasses on beaches of the Chukchi Sea in Alaska following a mortality event, September 2009. U.S. Geological Survey Open–File Report 2009–1291
Jay CV, Fishbach AS (2008) Pacific walrus response to Arctic sea ice losses. US Geological Survey Fact Sheet 2008–3041
Jay CV, Hills S (2005) Movements of walruses radio-tagged in Bristol Bay, Alaska. Arct 58:192–202
Jay CV, Udevitz MS, Kwok R, Fischbach AS, Douglas DC (2010) Divergent movements of walrus and sea-ice in northern Bering Sea. Mar Ecol Prog Ser 407:293–302
Jay CV, Fishbach AS, Kochnev AA (2012) Walrus areas used in the Chukchi Sea during sparse sea ice cover. Mar Ecol Prog Ser 468:1–13
Kochnev AA (1999) Pacific walrus in coastal waters of Wrangel Island (1991–1994). (Translation). News of the Pacific Fisheries Research Center 126, pp 447–464
Ovsyanikov NG, Bove LL, Kochnev AA (1994) Walrus mortality causes on hauling-out grounds. Zool Zh 73:80–87
Scadding GK (1990) Immunology of the tonsil: a review. J R Soc Med 83:104–107
Spraker TR, Lander ME (2010) Causes of mortality in northern fur seals (Callorhinus ursinus), St. Paul Island, Pribilof Islands, Alaska, 1986–2006. J Wildl Dis 46:450–473
Tynan CT, DeMaster DP (1997) Observations and predictions of Arctic climate change: potential effects on marine mammals. Arct 50:308–322
Udevitz MS, Taylor RL, Garlich-Miller JL, Quakenbush LT, Snyder JA (2012) Potential population-level effects of increased haulout-related mortality of Pacific walrus calves. Polar Bio 36:291–298
USFWS (2010) Pacific walrus (Odobenus rosmarus divergens): Alaska Stock. US Fish and Wildlife Service Stock Assessment Report
Acknowledgments
We acknowledge the following individuals: Anthony Fischbach, Dan Monson, Chad Jay, and Karen Oakley (U.S. Geological Survey, Alaska Science Center, Anchorage, AK); Joel Garlich-Miller, Jonathan Snyder, David Rippeto, and Eric Marek (U.S. Fish and Wildlife Service, AK); Jill Prewitt (Alaska SeaLife Center, Seward, AK); Craig George, Billy Adams, and the Bell 412 flight crew (North Slope Borough, Department of Wildlife Management and Search and Rescue, Barrow, AK); Harris Aguvluk (Wainwright, AK); Teri Rowles and the Working Group on Unusual Marine Mammal Mortality Events (National Oceanic and Atmospheric Administration) for their support of the response, both on and off site. Funding was provided by the National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, the Alaska SeaLife Center, and the North Slope Borough. We thank Glenn Olson, Doug Burn, Karen Wolf, and anonymous peers for reviewing the manuscript. Mention of trade names is for descriptive purposes only and does not constitute endorsement by the federal government.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest for the presented subject matter.
Rights and permissions
About this article
Cite this article
Goertz, C.E.C., Polasek, L., Burek, K. et al. Demography and pathology of a pacific walrus (Odobenus rosmarus divergens) mass-mortality event at Icy Cape, Alaska, September 2009. Polar Biol 40, 989–996 (2017). https://doi.org/10.1007/s00300-016-2023-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00300-016-2023-x