The State of Circumpolar Walrus Populations

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57 For these reasons, we suggest that it is premature to attempt to model future walrus habitat conditions across the species range. It may be possible to model specific populations, but data will still be lacking, to varying degrees (e.g., D.B. Stewart et al. 2014b). KNOWLEDGE GAPS AND RESEARCH NEEDS Active research is being conducted on all walrus populations, but numerous research gaps and sources of uncertainty remain (Table 5). In some cases, gaps are population-specific, for others, research is needed for all or most populations (e.g., recent estimates of population-specific growth rates; struck and lost rates for hunted populations). Knowledge gaps are summarized by five main categories (Table 5). We have not ranked knowledge gaps with respect to research priorities, as these decisions are better left to the specific research teams, management authorities and funding agencies. In many cases, there will a logical sequence of gaps that need filling to address information needs - for example, data on walrus distribution and seasonal movements will inform the design of surveys for abundance, and all these data are needed for comprehensive assessments of potential threats (e.g., industrial development, harvest rates, climate change). Responsible management jurisdictions could plan research agendas based on established research needs, with input from co-management partners and NGOs, as is currently being done by DFO in Canada (Stewart et al. in prep). International cooperation in the establishment of research goals and priorities is also important, and this type of cooperation is ongoing in many cases (e.g., harvest management for stocks shared between Canada and West Greenland, NAMMCO 2006; USA-Russia working groups, Meek et al. 2008; Schuessler 2016). Abundance, distribution, and movements There have been considerable recent advances in understanding of movements and seasonal distribution patterns for some walrus populations (e.g., satellite-tagging research in the Bering and Chukchi seas and at Svalbard (Lydersen et al. 2008; Freitas et al. 2009; Jay et al. 2010, 2012, 2014; Lydersen and Kovacs 2014)), but additional data would be beneficial in many cases. Among Atlantic walrus populations, recent (2015) satellite tracking of animals tagged in northwest Greenland suggests that the three stocks identified in the
58 Canadian High Arctic - Northwest Greenland (CHA-NWG) population are not as discrete as previously assumed (NAMMCO 2015). Additional research is needed to inform harvest management. For the Canadian Central Arctic - West Greenland (CCA-WG) population, an increased understanding of the seasonal movements between the two countries will improve inter-jurisdictional management of harvesting and other population stressors (e.g., oil and gas development). Seasonal movements within and between different areas occupied by this population (e.g., movements, if any, between Foxe Basin or South and East Hudson Bay and northwest Hudson Bay/Hudson Strait) could also be studied via tagging. The Canadian Low Arctic (CLA) population in southeast Hudson Bay is considered a separate population, but this is tentative as there are no data to confirm. Research on movement patterns of these animals (e.g., via satellite-tagging), particularly whether they move into Hudson Strait, is needed (also see Genetics, below). For the Kara Sea - Southern Barents Sea – Novaya Zemlya (KS-SBS-NZ) population, data on the distribution of walruses during the spring breeding season and on seasonal movements are needed. The relationship of Atlantic walruses in the Svalbard – Franz Josef Land Population (S- FJL) population to those in the KS-SBS-NZ population is uncertain (Born et al. 1995; NAMMCO 2006; Boltunov et al. 2010; Shitova et al. 2014b). There is extensive oil exploration, development and production currently taking place in the Pechora Sea and southwest Kara Sea. Data on walrus distribution and movements are needed to assess the risks posed by these industrial activities to walruses and their prey. For Pacific walruses, data on Laptev Sea walrus movements and distribution are needed. Movements of animals in the Bering and Chukchi Seas (BCS) population of Pacific walruses have been extensively studied through the use of satellite-telemetry (Jay and Garner 2002; Jay and Hills 2005; Jay et al. 2006, 2010, 2012, 2014), providing critical information for assessing impacts from industrial development and climate change. Continuing this work could provide valuable early information on the direction and extent of changes in walrus distribution and abundance in response to climate change and other stressors, and thereby benefit population management. Genetic data will also assist in understanding walrus movement patterns (see below). Abundance estimates are available for most populations, but with considerable uncertainty. Bias and imprecision in estimated population sizes over time leads to uncertainty in understanding trends in absolute population size (e.g., Taylor and Udevitz 2015). Population estimates are generally negatively biased due to incomplete survey coverage and methodological issues. Research on ways to increase the precision and accuracy of survey estimates using different methods (e.g., genetic capture-mark-recapture as an potential alternative to aerial surveys) and
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REPORT © Mikhail Cherkasov / WWF-R
Page 3 and 4:
2 ABSTRACT The walrus (Odobenus ros
Page 5 and 6:
4 PURPOSE AND SCOPE The WWF Arctic
Page 7 and 8: 6 beginning ca. 50,000 yBP that lim
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: 56 Hamilton et al. (2014) assessed
Page 61 and 62: 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
Page 67 and 68: 66 REFERENCES Allen, J.A. 1880. His
Page 69 and 70: 68 Boertmann, D., A. Mosbech, D. Sc
Page 71 and 72: 70 Chernook, V.I., C. Lydersen, D,M
Page 73 and 74: 72 Durner, G.M., D.C. Douglas, R.M.
Page 75 and 76: 74 Galicia, M.P., G.W. Thiemann, M.
Page 77 and 78: 76 Environmental Ltd., Edmonton AB
Page 79 and 80: 78 Collection of scientific papers
Page 81 and 82: 80 University of Guelph, Ontario, C
Page 83 and 84: 82 Noren S.R., M.S. Udevitz, and C.
Page 85 and 86: 84 Phillipa, J.D.W., F.A. Leighton,
Page 87 and 88: 86 Shitova M., M. Babushkin, A. Bol
Page 89 and 90: 88 Swenson, J.E., A. Bjørge, K. Ko
Page 91 and 92: 90 Witting, L. and E. Born. 2014. P
Page 93 and 94: 92 Figure 2. Atlantic walruses in F
Page 95 and 96: Figure 4. Map of Atlantic walrus po
Page 97 and 98: TABLES Table 1. Assessment of Atlan
Page 99 and 100: 98 Population 1 Stock or area 2 Sto
Page 101 and 102: 100 Table 2. Assessment of Pacific
Page 103 and 104: 102 Table 3. Conservation status of
Page 105 and 106: 104 Table 4. Summary of primary wal
Page 107 and 108: 106 Country Subspecies Hunt managem
Page 109 and 110:
108 Country Subspecies Hunt managem
Page 111 and 112:
110 Country Subspecies Hunt managem
Page 113 and 114:
112 Subspecies Population 1 Knowled
Page 115:
114 Subspecies Population 1 Knowled
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The State of Circumpolar Walrus Populations

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