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Underwater observations of foraging free-living Atlantic walruses (Odobenus rosmarus rosmarus) and estimates of their food consumption

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Abstract

Food consumption of Atlantic walruses (Odobenus rosmarus rosmarus L.) was quantified by combining underwater observations of feeding with satellite-telemetry data on movement and diving activity. The study was conducted between 31 July and 7 August 2001 in Young Sound (74°N–20°W) in Northeast Greenland. On ten occasions, divers were able to accompany foraging walruses to the sea floor and collect the shells of newly predated bivalves (Mya truncata, Hiatella arctica, Serripes groenlandicus) for determination of number of prey and biomass ingested per dive. Simultaneously, the activity of a 1,200-kg adult male walrus was studied by use of satellite-telemetry during an entire foraging cycle that included 74 h at sea followed by a 23-h rest on land. An average of 53.2 bivalves (SE=5.2, range: 34–89, n=10) were consumed per dive, corresponding to 149.0 g shell-free dry matter (SE=18.9, range: 62.4–253.1 g), or 2,576 kJ per dive (SE=325.2, range: 1,072–4,377 kJ). During the foraging trip, the walrus spent 57% of the time diving to depths of between 6 and 32 m, and it made a total of 412 dives that lasted between 5 and 7 min (i.e. typical foraging dives). If the entire feeding cycle is considered (97 h), the estimated daily gross energy intake was 214 kJ per kg body mass (95% CI: 153–275 kJ), corresponding to the ingestion of 57 kg (95% CI: 41–72 kg) wet weight bivalve biomass per day, or 4.7 (95% CI: 3.3–5.9%) of total walrus body mass. Due to ice cover, walrus access to the plentiful inshore bivalve banks in the area is restricted to the short summer period, where walruses rely on them for replenishing energy stores. It is hypothesised that the documented decrease in the extent and duration of Arctic sea ice may increase food availability for walruses in eastern Greenland in the future.

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References

  • Andersen LW, Born EW, Gjertz I, Wiig Ø, Holm LE, Bendixen C (1998) Population structure and gene flow of the Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Atlantic Arctic based on mitochondrial DNA and microsatellite variation. Mol Ecol:1323–1336

    Google Scholar 

  • Berthelsen E (1937) Contributions to the animal ecology of the fiords of Angmagssalik and Kangerdlugssuaq in East Greenland. Medd Grøn 108:1–58

    Google Scholar 

  • Born EW, Knutsen LØ (1990a) Immobilization of Atlantic walrus (Odobenus rosmarus rosmarus) by use of etorphine hydrochloride reversed by diprenorphine hydrochloride. Technical Report no. 14. Greenland Home Rule. Department of Wildlife Management, Nuuk

  • Born EW, Knutsen LØ (1990b) Satellite tracking and behavioural observations of Atlantic walrus (Odobenus rosmarus rosmarus) in NE Greenland in 1989. Technical Report no. 20. Greenland Home Rule. Department of Wildlife Management, Nuuk

  • Born EW, Knutsen LØ (1992) Satellite-linked radio tracking of Atlantic walruses (Odobenus rosmarus rosmarus) in northeastern Greenland, 1989–1991. Z Säugetierkd 57:275–287

    Google Scholar 

  • Born EW, Knutsen LØ (1997) Haul-out activity of male Atlantic walruses (Odobenus rosmarus rosmarus) in northeastern Greenland. J Zool Lond 243:381–396

    Google Scholar 

  • Born EW, Gjertz I, Reeves RR (1995) Population assessment of Atlantic walrus (Odobenus rosmarus rosmarus). Nor Polarinst Medd 138:1–100

    Google Scholar 

  • Born EW, Dietz R, Heide-Jørgensen MP, Knutsen LØ (1997) Historical and present status of the Atlantic walrus (Odobenus rosmarus rosmarus) in eastern Greenland. Medd Grøn Biosci 46:1–73

    Google Scholar 

  • Born EW, Andersen LW, Gjertz I, Wiig Ø (2001) A review of genetic relationships of Atlantic walruses (Odobenus rosmarus rosmarus) east and west of Greenland. Polar Biol 24:713–718

    Article  Google Scholar 

  • Born EW, Teilmann J, Riget F (2002) Haul-out activity of ringed seals (Phoca hispida) determined from satellite telemetry. Mar Mammal Sci 18:167–181

    Google Scholar 

  • Brawn VM, Peer DL, Bentley RJ (1968) Caloric content of the standing crop of benthic and epibenthic invertebrates of St. Margaret´s Bay, Nova Scotia. J Fish Res Board Can 25:1803–1811

    Google Scholar 

  • Cappelen J, Jørgensen BV, Laursen EV, Stannius LS, Thomsen RS (2001) The observed climate of Greenland 1958–99—with climatological standard normals, 1961–90. Technical report. Danish Meteorological Institute, Copenhagen

  • Fay FH (1982) Ecology and biology of the Pacific walrus, Odobenus rosmarus divergens Illiger. U.S. Department of the Interior Fish and Wildlife Service. North Am Fauna 74:1–279

    Google Scholar 

  • Fay FH, Burns JJ (1988) Maximal feeding depth of walruses. Arctic 41:239–240

    Google Scholar 

  • Fay FH, Bukhtiarov YA, Stoker SW, Shults LM (1984) Foods of the Pacific walrus in winter and spring in the Bering Sea. In: Fay FH, Fedoseev GA (eds) Soviet-American Cooperative Research on Marine Mammals, vol 1. Pinnipeds. NOAA Technical Reports NMFS 12. Washington, DC, pp 81–88

  • Fisher KI, Stewart REA, Kastelein RA, Campbell LD (1992) Apparent digestive efficiency in walruses (Odobenus rosmarus) fed herring (Clupea harengus) and clams (Spisula sp.). Can J Zool 70:30–36

    Google Scholar 

  • Førland EJ, Hanssen-Bauer I, Jónsson T, Kern-Hansen C, Nordli PØ, Tveito OE, Vaarby Laursen E (2002) Twentieth-century variations in temperature and precipitation in the Nordic Arctic. Polar Rec 38:203–210

    Google Scholar 

  • Gee JM, Warwick KM (1985) Effects of organic enrichment on meiofaunal abundance and community structure in sublittoral soft sediments. J Exp Mar Biol Ecol 91:247–262

    Google Scholar 

  • Genrich PH (1984) Nutritional and behavioural aspects of reproduction in walruses. MSc Thesis, University of Alaska, Fairbanks

  • Gjertz I, Griffiths D, Krafft BA, Lydersen C, Wiig Ø (2001) Diving and haul-out patterns of walruses Odobenus rosmarus on Svalbard. Polar Biol 24:314–319

    Article  Google Scholar 

  • Grebmeier JM, Feder HM, McRoy P (1989) Pelagic-benthic coupling on the shelf of the northern Bering and Chuckchi Seas. II. Benthic community structure. Mar Ecol Prog Ser 51:253–268

    Google Scholar 

  • Griffiths D, Wiig, Ø, Gjertz I (1993) Immobilization of walrus with etorphine HCl hydrochloride and Zoletil. Mar Mammal Sci 9:250–257

    Google Scholar 

  • Hanssen-Bauer I (2002) Temperature and precipitation in Svalbard 1912--2050: measurements and scenarios. Polar Rec 38:225–232

    Google Scholar 

  • Jay C, Farley SD, Garner GW (2001) Summer diving behaviour of male walruses in Bristol Bay, Alaska. Mar Mammal Sci 17:617–631

    Google Scholar 

  • Kastelein RA, Schooneman NM, Wiepkema PR (2000) Food consumption and body weight of captive Pacific walruses (Odobenus rosmarus divergens). Aquat Mammal 26:175–190

    Google Scholar 

  • Kelly BP (2001) Climate change and ice breeding pinnipeds. In: Walther et al. (eds) Kluwer/Plenum, New York, pp 43–55

  • King M (1995) Fisheries biology: assessment and management. Blackwell, Oxford

    Google Scholar 

  • Knutsen LØ, Born EW (1994) Body growth in Atlantic walruses (Odobenus rosmarus rosmarus) from Greenland. J Zool Lond 234:371–385

    Google Scholar 

  • Nagy KA, Girard IA, Brown TK (1999) Energetics of free-ranging mammals, reptiles, and birds. Annu Rev Nutr 1999:247–277

    Article  Google Scholar 

  • Ockelmann K (1958) Marine Lamellibranchiata. Medd Grøn 122:1–256

    Google Scholar 

  • Oliver JS, Slattery PN, O´Connor EF, Lowry LF (1983) Walrus, Odobenus rosmarus, feeding in the Bering Sea; a benthic perspective. Fish Bull 81:501–512

    Google Scholar 

  • Parkinson CL (1992) Spatial patterns of increases and decreases in the length of the sea ice season in the North Polar Region, 1979–1986. J Geophys Res 97:14377–14388

    Google Scholar 

  • Parkinson CL (2000) Variability of Arctic sea ice: the view from the space, an 18-year record. Arctic 53:341–358

    Google Scholar 

  • Payer J (1877a) Upptäcktsresor i Norra Polarhafvet (in Swedish). Bonniers, Stockholm

  • Payer J (1877b) Den østrisk-ungarnske Nordpol-Ekspedition i Aarene 1872–1872 (in Danish). Copenhagen

  • Peters W (1874) Die zweite deutsche Nordpolfärht in den Jahren 1869 und 1870 unter Führung des Kapitän Karl Koldewey. Brockhaus, Leipzig

  • Rothrock DA, Yu Y, Maykut GA (1999) Thinning of the Arctic sea-ice cover. Geophys Res Lett 26:3469–3472

    Article  Google Scholar 

  • Rysgaard S, Nielsen TG, Hansen B (1999) Seasonal variation in nutrients, pelagic primary production and grazing in a high-Arctic coastal marine ecosystem, Young Sound, Northeast Greenland. Mar Ecol Prog Ser 179:13–25

    CAS  Google Scholar 

  • Rysgaard S, Vang T, Stjernholm M, Rasmussen B, Windelin A, Kiilsholm S (2003) Physical conditions, carbon transport and climate change in a NE Greenland fjord. Arct Antarct Alp Res 35(3) (in press)

  • Sejr MK, Jensen KT, Rysgaard S (2000) Macrozoobenthos in a Northeast Greenland Fjord: structure and diversity. Polar Biol 23:792–801

    Article  Google Scholar 

  • Sejr MK, Sand MK, Jensen KT, Petersen JK, Christensen PB, Rysgaard S (2002) Growth and production of Hiatella arctica (Bivalvia) in a high-arctic fjord (Young Sound Northeast Greenland). Mar Ecol Prog Ser 244:163–169

    Google Scholar 

  • Sheffield G, Fay FH, Feder H, Kelly BP (2001) Laboratory digestion of prey and interpretation of walrus stomach contents. Mar Mammal Sci 17:310–330

    Google Scholar 

  • Thomson DH, Martin CM, Cross WE (1986) Identification and characterization of arctic nearshore benthic habitats. Can Tech Rep Fish Aquat Sci 1434:vii, 70p

  • Vibe C (1939) Preliminary investigation on shallow water animal communities in the Upernavik and Thule districts (Northwest Greenland). Medd Grøn 124:1–43

    Google Scholar 

  • Vibe C (1950) The marine mammals and the marine fauna in the Thule district (Northwest Greenland) with observations on the ice conditions in 1939–41. Medd Grøn 150:1–115

    Google Scholar 

  • Welch HE, Martin-Bergmann K (1990) Does the clam Mya truncata regenerate its siphon after predation by walrus? An experimental approach. Arctic 43:157–158

    Google Scholar 

  • Welch HE, Bergmann MA, Siferd TD, Martin KA, Curtis MF, Crawford RE, Conover RJ, Hop H (1992) Energy flow through the marine ecosystem of the Lancaster Sound region, Arctic Canada. Arctic 45:343–357

    Google Scholar 

  • Weslawski JM, Hacquebord L, Stempniewicz (2000) Greenland whales and walruses in the Svalbard food web before and after exploitation. Oceanologia 42:37–56

    Google Scholar 

  • Wiig Ø, Gjertz I, Griffiths D, Lydersen C (1992) Diving patterns of an Atlantic walrus Odobenus rosmarus rosmarus near Svalbard. Polar Biol 13:71–72

    Google Scholar 

  • Würsig B, Cipriano F, Würsig M (1991) Dolphin movement patterns: information from radio and theodolite tracking studies. In: Pryor K, Norris KS (eds) Dolphin societies. University of California Press, Los Angeles, pp 79–111

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Acknowledgements

This study was supported financially by the Danish National Science Foundation (SNF), the Commission for Scientific Research in Greenland (KVUG), the Greenland Institute of Natural Resources (GN) and the Danish Environmental Research Institute (DMU). We wish to thank veterinary Torsten Møller (Kolmården Zoological Garden, Kolmården, Sweden), the Danish Sirius Military Patrol in northeastern Greenland, and the Danish Polar Centre, for valuable support during the fieldwork. Dr. Ron A. Kastelein and two anonymous referees are thanked for offering useful comments to the paper. Finally, we thank Anna Haxen for polishing our English.

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Authors and Affiliations

  1. Greenland Institute of Natural Resources, P.O. Box 570, 3900, Nuuk, Greenland

    E. W. Born & N. Levermann

  2. National Environmental Research Institute, Department of Marine Ecology, Vejlsøvej 25, 8600 , Silkeborg, Denmark

    S. Rysgaard & M. Sejr

  3. Waterproof Diving International, Industrivägen 37, 43361, Partille, Sweden

    G. Ehlmé

  4. University of Aarhus, Department of Marine Ecology, Finlandsgade 14, 8000 , Aarhus N, Denmark

    M. Sejr

  5. National Environmental Research Institute, Department of Arctic Environment, P.O. Box 358, 4000, Roskilde, Denmark

    M. Acquarone

  6. University of Copenhagen, Department of Population Ecology, Universitetsparken 15, , 2100, Copenhagen Ø, Denmark

    N. Levermann

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  1. E. W. Born
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Correspondence to E. W. Born.

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Born, E.W., Rysgaard, S., Ehlmé, G. et al. Underwater observations of foraging free-living Atlantic walruses (Odobenus rosmarus rosmarus) and estimates of their food consumption. Polar Biol 26, 348–357 (2003). https://doi.org/10.1007/s00300-003-0486-z

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