The State of Circumpolar Walrus Populations

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5 1. Canadian High Arctic - Northwest Greenland (Canada, Greenland) 2. Canadian Central Arctic - West Greenland (Canada, Greenland) 3. Canadian Low Arctic (Canada) 4. East Greenland (Greenland) 5. Svalbard - Franz Josef Land (Norway, Russia) 6. Kara Sea - Southern Barents Sea - Novaya Zemlya (Russia) These populations are distinguished by the degree of genetic interchange and other factors such as geographical separation, contaminants, and lead isotope ratios and signatures. Some populations are comprised of different management stocks that have been identified for harvest management. A seventh population (Nova Scotia/Newfoundland/Gulf of St Lawrence) was historically abundant in the southwestern Gulf of St Lawrence and on the Scotian Shelf in eastern Canada (Allen 1880; Reeves 1978; Born et al. 1995). It was extirpated ca. 1850 by extensive commercial hunting (D.B. Stewart et al. 2014a). This population appears to have been morphologically and genetically distinct from other walruses in the north Atlantic (McLeod et al. 2014). Its extirpation has reduced the adaptive potential of Atlantic walruses. Commercial hunting is no longer permitted, but re-establishment of this population is unlikely due to the increase in other human activities in the region. Occasional recent sightings are not considered a sign of re-establishment (COSEWIC 2006). Available population estimates for Atlantic walrus populations are summarized in Table 1. These estimates are negatively biased due to incomplete survey coverage and methodological problems (e.g., opportunistic counts versus standardized surveys, unknown population composition on wintering grounds). The age-class distributions of these populations are unknown. Status ranks assigned by responsible jurisdictions to the different populations are summarized in Table 3. Canadian High Arctic - Northwest Greenland (CHA-NWG) population The Canadian High Arctic - Northwest Greenland (CHA-NWG) population is shared by Canada and Greenland (Figure 3), and was formerly referred to as the North Water (Baffin Bay-Eastern Canadian Arctic) population (Born et al. 1995). There are significant genetic differences between walruses in this population and those in the Canadian Central Arctic - West Greenland (CCA-WG) population (Andersen and Born 2000; Andersen et al. 2014; Shafer et al. 2014). Modelling suggests that these populations may have split from one another ca. 145,000 yBP, followed by greater gene flow from the CHA-NWG population to the CCA-WG population, with a bottleneck
6 beginning ca. 50,000 yBP that limited recovery of the CHA-NWG population (Shafer et al. 2015). Information on walrus distribution and movements supports the geographical isolation of this population (Born et al. 1995; COSEWIC 2006). Observations of walruses farther west, to the north and east of Victoria Island in the Canadian Arctic Archipelago, have been interpreted as extra-limital occurrences of animals from this population (Harrington 1966). Some walruses move to ice edges in Lancaster Sound or eastern Jones Sound or into the North Water to overwinter, and others appear to winter at polynyas or in areas of rotten ice within the Canadian Arctic Archipelago (Riewe 1976; Davis et al. 1978; Killian and Stirling 1978; Stirling et al. 1983; Born et al. 1995; Sjare and Stirling 1996). Animals from the Baffin Bay stock cross from Greenland to Ellesmere Island in the spring and presumably return in the fall (Born et al. 1995; NAMMCO 2015). In May 2009 walruses were distributed in a belt across the southern part of the North Water from Greenland to Ellesmere Island, over both shallow and deep (>500 m) water (Heide-Jorgensen et al. 2013). During the open-water period walruses are concentrated along the east coast of Ellesmere Island and rare in the waters off northwest Greenland (R.E.A. Stewart et al. 2014a). Satellite tracking of animals tagged (n=21) in June 2015 at Wolstenholme Fjord followed them moving across the North Water to the east coast of Ellesmere Island (NAMMCO 2015:29). Some animals moved north along the coast of Ellesmere Island, others far west into Jones Sound, and 3 went south of Devon Island into Lancaster Sound and then west to Cornwallis Island. These movements confirm that this walrus population extends from Greenland westward well into the Canadian high Arctic. Three management stocks have been tentatively identified within the CHA-NWG population on the basis of satellite-linked radio tagging studies, observed seasonal distribution, and lead isotope ratios in the teeth (Stewart 2008; NAMMCO 2011; see also Outridge et al. 2003). These stocks are located in Penny Strait-Lancaster Sound (Canada), western Jones Sound (Canada), and Baffin Bay (Canada and West Greenland). Results from the 2015 tagging (NAMMCO 2015:29) may necessitate revisiting of these stock delineations. Aerial surveys of walrus haulouts in August 2009 yielded best estimates of about 727 walruses in Penny Strait-Lancaster Sound, 503 in western Jones Sound, and 1,251 in Baffin Bay (east coast of Ellesmere Island) (R.E.A. Stewart et al. 2014a, b; Table 1). The first two stocks seem stable over three decades, and the population trend for the shared Baffin Bay stock is unknown. Baffin Bay walruses were also recently surveyed by Greenland researchers, with abundance estimates from May 2009 (1,238 CV=0.19), May 2010 (1,759 CV=0.29; Heide-Jorgensen et al. 2013:605), and April 2014 (2,544 95%CI 1,513-4,279; NAMMCO 2015:29) derived from line-transect surveys of the North Water that were corrected for animals submerged below the detection depth (Heide- Jorgensen et al. 2013:605; NAMMCO 2015:29). While there is good agreement among these
Page 1 and 2: REPORT © Mikhail Cherkasov / WWF-R
Page 3 and 4: 2 ABSTRACT The walrus (Odobenus ros
Page 5: 4 PURPOSE AND SCOPE The WWF Arctic
Page 9 and 10: 8 Walruses from the Foxe Basin stoc
Page 11 and 12: 10 al. 2003). These differences coi
Page 13 and 14: 12 under favourable environmental c
Page 15 and 16: 14 appeared to be male. Crude measu
Page 17 and 18: 16 comparable data for proper asses
Page 19 and 20: 18 (Fay 1982). The walruses that ar
Page 21 and 22: 20 A joint U.S.-Russia survey, with
Page 23 and 24: 22 for the conservation of walruses
Page 25 and 26: 24 provisions for walrus protection
Page 27 and 28: 26 northwestern and northeastern Gr
Page 29 and 30: 28 Franz Josef Land was discovered
Page 31 and 32: 30 USFWS 2014). The population is c
Page 33 and 34: 32 they return from hunting trips (
Page 35 and 36: 34 The USFWS has also developed gui
Page 37 and 38: 36 how many walruses are represente
Page 39 and 40: 38 (www.iucn.org/about/). The IUCN
Page 41 and 42: 40 Atlantic Walruses In Canada, the
Page 43 and 44: 42 Pacific walruses The primary sou
Page 45 and 46: 44 Foxe Basin (BIMC 2012). It has b
Page 47 and 48: 46 define shipping channels, season
Page 49 and 50: 48 Alaska may be a successful manag
Page 51 and 52: 50 of the population (Born et al. 1
Page 53 and 54: 52 In the Bering and Chukchi seas,
Page 55 and 56: 54 Garlich-Miller et al. (2011) ass
Page 57 and 58:
56 Hamilton et al. (2014) assessed
Page 59 and 60:
58 Canadian High Arctic - Northwest
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60 2014a, b; Lindqvist et al. 2016)
Page 63 and 64:
62 reproduction and survival rates,
Page 65 and 66:
64 Jurisdictions with walrus popula
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66 REFERENCES Allen, J.A. 1880. His
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68 Boertmann, D., A. Mosbech, D. Sc
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70 Chernook, V.I., C. Lydersen, D,M
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72 Durner, G.M., D.C. Douglas, R.M.
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74 Galicia, M.P., G.W. Thiemann, M.
Page 77 and 78:
76 Environmental Ltd., Edmonton AB
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78 Collection of scientific papers
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80 University of Guelph, Ontario, C
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82 Noren S.R., M.S. Udevitz, and C.
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84 Phillipa, J.D.W., F.A. Leighton,
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86 Shitova M., M. Babushkin, A. Bol
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88 Swenson, J.E., A. Bjørge, K. Ko
Page 91 and 92:
90 Witting, L. and E. Born. 2014. P
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92 Figure 2. Atlantic walruses in F
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Figure 4. Map of Atlantic walrus po
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TABLES Table 1. Assessment of Atlan
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98 Population 1 Stock or area 2 Sto
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100 Table 2. Assessment of Pacific
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102 Table 3. Conservation status of
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104 Table 4. Summary of primary wal
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106 Country Subspecies Hunt managem
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Page 111 and 112:
Page 113 and 114:
112 Subspecies Population 1 Knowled
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114 Subspecies Population 1 Knowled
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The State of Circumpolar Walrus Populations

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