Last updated 10 May 2019

The Svalbard walrus (Odobenus marinus) population was hunted to near extinction hundreds of years ago and remains Red Listed (Vulnerable) today. Surveys on haul-out sites show that the number of walruses in Svalbard is increasing.

Walrus colony on Svalbard. Photo: Geir Wing Gabrielsen / Norwegian Polar Insitute

What is being monitored?


Population in Svalbard

In the 1980s and 1990s, estimates were made from observations from land or ships, spread out over weeks or months. Data from 2006 and 2012 are based on the number of animals on aerial photographs, and counts are corrected for the proportion of animals at sea at the time of the survey.
(Cite these data: Norwegian Polar Institute (2022). Walrus population in Svalbard. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL: http://www.mosj.no/en/fauna/marine/walrus-population.html)

Details on these data

Update intervalEvery 5th year
Next updateOctober 2023
Commissioning organizationMinistry of Climate and Environment
Executive organizationNorwegian Polar Institute
Contact personsKit M. Kovacs

Method

High resolution aerial photography at all known haul-out sites. Annual updates on localities used by walruses are obtained  through the Marine Mammals Sightings Database.

Correction factors are required to adjust for animals in the water at the time of the surveys. These should be updated for each survey interval.

Other metadata

Data are stored at the Norwegian Polar Institute.

Reference level and action level

No reference level or action limit are set.

Status and trend

Walruses were once extremely abundant in the Svalbard Archipelago, but 350 years of unregulated harvest brought them to the brink of extinction before they were protected in 1952. Born (1984) summarized observations of walruses in the Svalbard area from 1954–1982 and concluded that the summering stock was about 100 animals, and that there had been an increase in numbers since 1970. In 1993, a total of 741 walruses were observed in Svalbard based on maximum numbers of animals counted at various haul-out sites during fixed-wing and ground surveys performed over the period from August-October (Gjertz and Wiig 1995). It has been documented by several studies that the walruses in Svalbard are part of a larger, common Svalbard – Franz Josef Land population. Based on this fact and an assumed equal sex ratio, Gjertz and Wiig (1995) suggested that this shared population consisted of a minimum of 1450 walruses (age 2+, plus an unknown number of calves). These reports supported the general impression of a slow recovery taking place, based on increasing numbers of sightings of walruses at an increasing number of haul-out sites in Svalbard (Norwegian Polar Institute’s Fauna and Marine Mammal Sightings Databases). The sex ratio in the Svalbard area over the decades between the 1950s and 1990s was highly skewed. Most walruses repatriating the archipelago were males; females were almost entirely restricted to a few haul-out sites in the northeast corner of Nordaustlandet and accounted for only a few per cent of the population. This is in marked contrast to the 33% of the population that was comprised of females during the harvesting in the 1800s (Wiig et al. 2007).

The first systematic abundance survey for MOSJ was conducted in 2006 (Lydersen et al. 2008). This survey covered all known terrestrial haul-out sites within Svalbard (79 in total) during a tight time window (1–3 August). 17 haul-out sites were occupied by animals when the survey was flown. The photographs of the active sites revealed 657 animals. An extensive behavioural data set from satellite-relay-data-loggers was used to correct for animals that were in the water at the time of the survey. The resulting estimate was 2629 (95% CI: 2318–2998).

The second survey in this MOSJ time series was flown in 2012 (Kovacs et al. 2014), and the new estimate is 3886 (95% CI: 3553–4262). 91 haul-out sites are now registered in the Polar Institute’s terrestrial haul-out data-base, and 24 of them were occupied during the survey. 9 of the active sites contained females with calves, in contrast to 1 site in the 2006 survey.

The third survey in this time series was carried out in 2018. At the time of the survey 5503 (95% CI: 5031-6036) walrus were estimated in the Svalbard area. This is a 41.6% increase since the previous survey. Animals were present at 19 of the visited haul-out sites, and calves were observed at seven of these. In 2018 there were 98 terrestrial walrus haul-out sites in the data base for Svalbard.

Causal factors

Walruses were once extremely abundant in Svalbard, but 350 years of unregulated harvest brought them to the brink of extinction. Walruses were protected in Svalbard in 1952, at a time when there were only a hundred animals left.

After more than 60 years of protection, the population size in Svalbard is still small, and the species is still on the Red List as a threatened species. The number of walruses has been increasing in recent years, and walruses have gradually been observed on haul-out sites where they have not been observed for many decades.

The last survey from 2018 shows that the number of walruses in Svalbard is increasing.

Consequences

In common with other Arctic species that have been harvested way beyond sustainable levels, we do not know how abundant the species might be after harvest ends, as this also depends on the carrying capacity of the environment.

The walrus is less vulnerable for changes in sea ice extent than other species, but this does not mean that the population will not respond to rapid climate change.

About the monitoring

The Svalbard walrus population was hunted to near extinction hundreds of years ago and remains Red Listed (Vulnerable) today. Its distribution, abundance and response(s) to climate change, particularly sea ice, should be carefully monitored.

Relations to other monitoring

Monitoring programme

International environmental agreements

  • None

Voluntary international cooperation

Related monitoring

  • There is a lot of relevant scientific data available that is currently not incorporated in MOSJ. A plan exists for proper CAFF-CBMP monitoring of this species, which is not yet implemented in Norway.

Further reading

Publications

  1. Andersen, L.W., Born, E.W., Gjertz, I., Wiig, Ø., Holm, L.-E., 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. Molecular Ecology 7(10): 1323–1336.
    DOI:10.1046/j.1365-294x.1998.00455.x
  2. Freitas, C., Kovacs, K.M., Ims, R.A., Fedak, M.A., Lydersen, C. 2009. Deep into the ice: over-wintering and habitat selection in male Atlantic walruses. Marine Ecology Progress Series 375: 247–261.
    DOI:10.3354/meps07725
  3. Gjertz, I., Wiig, Ø. 1995. The number of walruses (Odobenus rosmarus) in Svalbard in summer. Polar Biology 15.
  4. Hamilton, C., Kovacs, K.M., Lydersen, C. 2015. Year-round haul-out behaviour of male walruses Odobenus rosmarus in the Northern Barents Sea. Marine Ecology Progress Series 519: 251–263.
    DOI:10.3354/meps11089
  5. Kovacs, K.M., Aars, J., Lydersen, C. 2014. Walruses recovering after 60+ years of protection in Svalbard, Norway. Polar Research 33: 26034.
    DOI:10.3402/polar.v33.26034
  6. Kovacs, K.M., Lemons, P., MacCracken, J.G., Lydersen, C. 2015. Walruses in a Time of Climate Change. Pp. 66–74 in: Arctic Report Card: Update for 2015. National Oceanic and Atmospheric Administration (NOAA).
  7. Lowther, A.D., Kovacs, K.M., Griffiths, D., Lydersen, C. 2015. Identification of motivational state in adult male Atlantic walruses inferred from changes in movement and diving behavior. Marine Mammal Science 31(4): 1291–1313.
    DOI:10.1111/mms.12224
  8. Lydersen, C., Kovacs, K.M. 2014. Walrus Odobenus rosmarus research in Svalbard, Norway, 2000-2010. NAMMCO Scientific Publications 9: 175–190.
    DOI:10.7557/3.2613
  9. Lydersen, C., Aars, J., Kovacs, K.M. 2008. Estimating the number of walruses in Svalbard from aerial surveys and behavioural data from satellite telemetry. Arctic 61(2): 119–128.
  10. Norderhaug, M. 1969. Hvalrossens (Odobenus rosmarus) forekomst i Svalbardområdet 1960-1967. Norsk Polarinstitutt Årbok.
  11. Routti, H., Diot, B., Panti, C., Duale, N., Fossi, M.C., Harju, M., Kovacs, K.M., Lydersen, C., Scotter, S.E., Villanger, G.D., Bourgeon, S. 2019. Contaminants in Atlantic walruses in Svalbard Part 2: Relationships with endocrine and immune systems. Environmental Pollution 246: 658–667.
    DOI:10.1016/j.envpol.2018.11.097
  12. Scotter, S.E., Tryland, M., Nymo, I.H., Hanssen, L., Harju, M., Lydersen, C., Kovacs, K.M., Klein, J., Fisk, A.T., Routti, H. 2019. Contaminants in Atlantic walruses in Svalbard part 1: Relationships between exposure, diet and pathogen prevalence. Environmental Pollution 244: 9–18.
    DOI:10.1016/j.envpol.2018.10.001
  13. Skoglund, E.G. 2006. Fatty acid composition of blubber and dermis of Atlantic walrus (Odobenus rosmarus rosmarus) on Svalbard, and its potential prey.
  14. Tryland, M., Lydersen, C., Kovacs, K.M., Thoresen, S.I. 2009. Serum chemistry reference values in free-ranging North Atlantic male walruses (Odobenus rosmarus rosmarus) from the Svalbard archipelago. Veterinary Clinical Pathology 38(4): 501–506.
    DOI:10.1111/j.1939-165X.2009.00154.x
  15. Wiig, Ø., Born, E.W., Gjertz, I., Lydersen, C., Stewart, R.E.A. 2007. Historical sex-specific distribution of Atlantic walrus (Odobenus rosmarus rosmarus) in Svalbard assessed by mandible measurements. Polar Biology 31(1): 69–75.
    DOI:10.1007/s00300-007-0334-7
  16. Wiig, Ø., Gjertz, I., Griffiths, D. 1996. Migration of Walruses (Odobenus rosmarus) in the Svalbard and Franz Josef Land area. Journal of Zoology 238(4): 769–784.
  17. Wolkers, H., van Bavel, B., Ericson, I., Skoglund, E., Kovacs, K.M., Lydersen, C. 2006. Congener-specific accumulation and patterns of chlorinated and brominated contaminants in adult male walruses from Svalbard, Norway: Indications for individual-specific prey selection. Science of The Total Environment 370(1): 70–79.
    DOI:10.1016/j.scitotenv.2006.06.005
  18. Ølberg, R.-A., Kovacs, K.M., Bertelsen, M.F., Semenova, V., Lydersen, C. 2017. SHORT DURATION IMMOBILIZATION OF ATLANTIC WALRUS (ODOBENUS ROSMARUS ROSMARUS) WITH ETORPHINE, AND REVERSAL WITH NALTREXONE. Journal of Zoo and Wildlife Medicine 48: 972–978.
    DOI:10.1638/2016-0232R.1
  19. Øren, K., Kovacs, K.M., Yoccoz, N.G., Lydersen, C. 2018. Assessing site-use and sources of disturbance at walrus haul-outs using monitoring cameras. Polar Biology 41: 1737–1750.
    DOI:10.1007/s00300-018-2313-6