Abstract
The Pacific walrus (Odobenus rosmarus divergens) is considered to be a single panmictic population for management purposes. However, studies on population structuring in this species are limited; in part, because portions of the population’s range are often inaccessible. Therefore, alternative and complementary methods for investigating stock structure in the Pacific walrus are of particular interest. We used measures of elemental concentrations in whole tooth sections from ICP-MS in a discriminant analysis to investigate evidence of stock separation between walruses from two of three known breeding areas (S.E. Bering, St Lawrence, and Anadyr Gulf). Elemental compositions of teeth from female and male walruses from the S.E. Bering and St Lawrence breeding areas were significantly different, providing evidence of separate stocks. We also obtained insights into the potential relation of walruses from non-breeding areas to walruses from these breeding groups based on similarities in their dental elemental profiles.
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References
Amstrup SC, Durner GM, Stirling I, Lunn NJ, Messier F (2000) Movements and distribution of polar bears in the Beaufort Sea. Can J Zool 78:948–966
Barlow J, Swartz SL, Eagle TC, Wade PR (1995) U.S. marine mammal stock assessments: guidelines for preparation, background, and a summary of the 1995 assessments. NOAA Tech Memo NMFS-OPR-6
Cadrin SX, Friedland KD, Waldman JR (2005) Stock identification methods. Elsevier, Burlington
Cronin MA, Amstrup SC, Scribner KT (2006) Microsatellite DNA and mitochondrial DNA variation in polar bear (Ursus maritimus) from the Beaufort and Chukchi seas, Alaska. Can J Zool 84:655–660
Cronin MA, Hills S, Born EW, Patton JC (1994) Mitochondrial DNA variation in Atlantic and Pacific walruses. Can J Zool 72:1035–1043
Dizon AE, Lockyer C, Perrin WF, DeMaster DP, Sisson J (1992) Rethinking the stock concept: a phylogeographic approach. Conserv Biol 6:24–36
Evans RD, Richner P, Outridge PM (1995) Micro-spatial variations of heavy metals in the teeth of walrus as determined by laser ablation ICP-MS: the potential for reconstructing a history of metal exposure. Arch Environ Contam Toxicol 28:55–60
Fay FH (1982) Ecology and biology of the Pacific walrus, Odobenus rosmarus divergens Illiger. United States Department of the Interior, Fish and Wildlife Service, North American Fauna, Number 74. Washington, D.C
Fay FH (1985) Odobenus rosmarus. Mammalian species No. 238. The American Society of Mammalogists
Fay FH, Kelly BP, Gehnrich PH, Sease JL, Hoover AA (1984) Modern populations, migrations, demography, trophics, and historical status of the Pacific walrus. U.S. Dep. Commer., NOAA. OCSEAP Final Rep 37:231–376
Garlich-Miller J (1997) Age, sex, and reproductive status of Pacific walrus harvested in the Bering Strait region, 1994–1996. USFWS R7 MMM Technical Report 97-1. U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska
Garlich-Miller JL, Stewart REA, Stewart BE, Hiltz EA (1993) Comparison of mandibular with cemental growth-layer counts for ageing Atlantic walrus (Odobenus rosmarus rosmarus). Can J Zool 71:163–167
Gehnrich PH (1984) Nutritional and behavioral aspects of reproduction in walruses. MSc Thesis. University of Alaska, Fairbanks
Gilbert JR (1989) Aerial census of Pacific walruses in the Chukchi Sea, 1985. Mar Mammal Sci 5:17–28
Gilbert JR (1999) Review of previous Pacific walrus surveys to develop improved survey designs. In: Garner GW, Amstrup SC, Laake JL, Manly BFJ, McDonald LL, Roberston DG (eds) Marine mammal survey and assessment methods. A.A. Balkema, Rotterdam, pp 75–84
Hills S, Robson BW, Seagars DJ (1991) Cruise report: USSR-US joint pinniped research, ZRS Zaslonovo, Bering Sea, 28 March–21 May 1991. Available: http://www.arlis.org/docs/vol1/55490098.pdf]
Hinners TA, Hughes R, Outridge PM, Davis WJ, Simon K, Woolard DR (1998) Interlaboratory comparison of mass spectrometric methods for lead isotopes and trace elements in NIST SRM 1400 Bone Ash. J Anal Atom Spectrom 13:963–970
Jay CV, Hills S (2005) Movements of walruses radio-tagged in Bristol Bay, Alaska. Arctic 58:192–202
Mansfield AW (1958) The biology of Atlantic walrus, Odobenus rosmarus rosmarus (Linnaeus) in the eastern Canadian Arctic. Manuscript Report 653. Fisheries Research Board of Canada
McGarigal K, Cushman S, Stafford S (2000) Multivariate statistics for wildlife and ecology research. Springer, New York
Miles AK, Hills S (1994) Metals in diet of Bering Sea walrus: Mya sp. as a possible transmitter of elevated cadmium and other metals. Mar Pollut Bull 28:456–458
Mimrin NI, Smirnov GP, Gaevsky AS, Kovalenko VE (1990) The distribution and abundance of walruses in the Anadyr Gulf of the Bering Sea. Zool Zh 69:105–113 (Translated from Russian)
National Oceanic and Atmospheric Administration (1987) Bering, Chukchi, and Beaufort Seas coastal and ocean zones strategic assessment: Data atlas. Strategic Assessment Branch, Ocean Assessments Division, Office of Oceanography and Marine Assessment, National Ocean Service, National Oceanic and Atmospheric Administration, Rockville, Maryland
National Oceanic and Atmospheric Administration (2005) Revisions to guidelines for assessing marine mammal stocks (GAMMS II). Guidelines for preparing stock assessment reports pursuant to Section 117 of the Marine Mammal Protection Act. Available from NOAA Fisheries Office of Protected Resources (http://www.nmfs.noaa.gov/pr/pdfs/sars/gamms2005.pdf)
Outridge PM, Davis WJ, Stewart REA, Born EW (2003) Investigation of the stock structure of Atlantic walrus (Odobenus rosmarus rosmarus) in Canada and Greenland using dental Pb isotopes derived from local geochemical environments. Arctic 56:82–90
Outridge PM, Evans RD, Wagemann R, Stewart REA (1997) Historical trends of heavy metals and stable lead isotopes in beluga (Delphinapterus leucas) and walrus (Odobenus rosmarus rosmarus) in the Canadian Arctic. Sci Total Environ 203:209–219
Outridge PM, Stewart REA (1999) Stock discrimination of Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Canadian Arctic using lead isotope and element signatures in teeth. Can J Fish Aquat Sci 56:105–112
Popov LA, Kibal’chich AA, Bukhtiyarov YA, Yurakhno MV (1981) Materials from investigation of pinnipeds during the expedition on the ZRS Zvyagino in the Bering Sea, February–March 1981. In: Popov LA (ed) Scientific investigational work on marine mammals in the Northern Part of the Pacific Ocean 1980–81. All-Union Scientific Investigational Institute of Marine Fisheries and Oceanography (VINRO), Moscow, pp 38–54 (Translated by FH Fay)
Scribner KT, Hills S, Fain SR, Cronin MA (1997) Population genetics studies of the walrus (Odobenus rosmarus): a summary and interpretation of results and research needs. Mol Genet Mar Mammal Spec Publ 3:173–184
Smirnov G, Rinteimit V, Agnakisyak M, Litovka M (2002) Walrus harvest monitoring on Chukotka in 2001. Russian technical report prepared for the U.S. Fish and Wildlife Service and Kawerak Incorporated (Translated)
Stern RA, Outridge PM, Davis WJ, Stewart REA (1999) Reconstructing lead isotope exposure histories preserved in the growth layers of walrus teeth using the SHRIMP II ion microprobe. Environ Sci Technol 33:1771–1775
Stewart REA, Outridge PM, Stern RA (2003) Walrus life-history movements reconstructed from lead isotopes in annual layers of teeth. Mar Mammal Sci 19:806–818
Tabachnick BG, Fidell LS (1996) Using multivariate statistics. HarperCollins College Publishers, New York
Thomas CA, Bendell-Young LI (1998) Linking the sediment geochemistry of an intertidal region to metal bioavailability in the deposit feeder Macoma balthica. Mar Ecol-Prog Ser 173:197–213
U.S. Fish and Wildlife Service (2002) Pacific walrus (Odobenus rosmarus divergens): Alaska stock (Revised July 12, 2002). Available from Marine Mammals Management, U.S. Fish and Wildlife Service, Anchorage, Alaska
Wade PR, Angliss RP (1996) Report of the guidelines for assessing marine mammal stocks (GAMMS) workshop. Seattle, WA. NOAA Tech Memo NMFS-OPR-12
Wiig Ø, Gjertz I, Griffiths D (1996) Migration of walruses (Odobenus rosmarus) in the Svalbard and Franz Josef Land area. J Zool 238:769–784
Acknowledgments
We thank G. Smirnov of ChukotTINRO for tooth samples from Native subsistence hunts in Russia. B. Kelly kindly provided tooth samples archived from the Zakharovo Russia-U.S. joint pinniped research cruises. The office of Marine Mammals Management of the U.S. Fish and Wildlife Service (USFWS) provided facilities for tooth preparation and samples archived from the Zaslonovo Russia-U.S. joint pinniped research cruise. Additional tooth samples were provided by USFWS Walrus Harvest Monitoring Program and Alaska Native hunters. We thank Y. Gillis for sorting and cutting many of the tooth samples. International transport of tooth samples was accomplished under USFWS Division of Management Authority permit number MA801652-3. Any use of trade names is for descriptive purposes only and does not imply endorsement of the U.S. Government.
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Jay, C.V., Outridge, P.M. & Garlich-Miller, J.L. Indication of two Pacific walrus stocks from whole tooth elemental analysis. Polar Biol 31, 933–943 (2008). https://doi.org/10.1007/s00300-008-0432-1
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DOI: https://doi.org/10.1007/s00300-008-0432-1