1046 



Fishery Bulletin 97(4), 1999 



believe that this difference, which reflects inter- 

 annual variability in the hunting success of non- 

 WHMP villages, more accurately reflects statewide 

 harvest levels for these two yeai's. For the reasons 

 stated above, the FWS has adopted the use of the 

 proportional equation to estimate the size of the 

 walrus harvest. 



In 1992, the assumption that all retrieved walrus 

 were redsorded during WHMP operations was not met. 

 In this instance we considered the uncorrected MTRP 

 data as a minimum harvest estimate for that year. 

 The WHMP was re-initiated in 1992 after a two-year 

 hiatus; the lack of experienced personnel likely con- 

 tributed to the poor monitoring results that season. 

 Since that time, program managers have attempted 

 to improve the program by hiring experienced moni- 

 tors and additional village assistants to meet all re- 

 turning boats and by emphasizing the importance of 

 recording all retrieved animals (Dickerson-^). 



Another assumption of the proportional equation 

 is that compliance in the villages of Gambell. 

 Savoonga, and Diomede is representative of non- 

 WHMP villages. Compliance was variable between 

 villages and years, suggesting that thei'e was little 

 correlation between the two progi'ams. Since conduct- 

 ing analyses of MTRP compliance, information and 

 education efforts in these villages appear to have 

 been effective at increasing compliance. The accu- 

 racy of this method could be improved by increasing 

 the number of villages in the WHMP. 



In both the prediction and proportional equations, 

 estimates are based on the number of walrus that 

 are retrieved by hunters. Fay et al. ( 1994) estimated 

 that 427c of walrus struck by hunters are not re- 

 trieved and subsequently die at sea. In order to esti- 

 mate total human-caused removals from the Pacific 

 walrus population, harvest estimates are adjusted 

 to account for animals struck and lost. 



Accurate harvest data are vital to the management 

 of the Pacific walrus population. Harvest data are 

 incorporated into stock assessment reports that chart 

 the status and trend of the population. The stock 

 assessment process compares estimates of human- 

 caused mortality with a calculated potential biologi- 

 cal removal (PBR) level to determine the status of a 

 stock. One of the reasons a stock may be designated 

 as "strategic" depends upon whether or not its level 

 of human-caused mortality exceeds the calculated 

 PBR level (Wade, 1998). Since 1992, most human 

 caused mortality affecting the Pacific walrus popu- 

 lation has been associated with walrus hunting ac- 

 tivities in Alaska and Chukotka. Between 1992 and 

 1996 the combined annual take of walrus in the U.S. 

 and Russia averaged 4869 walrus per year (Gorbics 

 et al.''). Russian harvest data are currently unavail- 



able for 1997. Because annual estimates of human 

 caused mortality have been lower than the calculated 

 PBR of 7533 the population has been classified as non- 

 strategic (Gorbics et al.''). It is essential that harvest 

 monitoring in both nations be maintained in order to 

 accurately assess the impact of the harvest to this stock. 

 In summary, this new method of harvest estima- 

 tion uses data from both harvest monitoring pro- 

 grams to account for interannual and intervillage 

 variability in hunting success and applies a correc- 

 tion factor to adjust total harvest estimate to account 

 for noncompliance with the MTRP. The accuracy of 

 harvest estimates is therefore dependent upon the 

 degi'ee of hunter compliance with the MTRP rule. It 

 is hoped that through ongoing information and edu- 

 cation efforts that explain the importance of accu- 

 rate harvest data, the understanding of and compli- 

 ance with monitoring programs will improve. 



Acknowledgments 



We would like to acknowledge the hard work and 

 dedication of the MTRP taggers and WHMP harvest 

 monitors. Harvest monitoring activities were coor- 

 dinated by Larry Dickerson, Polly Hessing, Dana 

 Seagars, and Wells Stephensen. This manuscript was 

 improved by constructive comments offered by the fol- 

 lowing reviewers: Susan Lapkass, Larry Dickerson, 

 Susan Hills, and Mark Udevitz. 



Literature cited 



Burn, D. M. 



1998. Estimation of hunter compliance with the Marine 

 Mammal Marking. Tagging, and Reporting Program for 

 walru.s. Wild. .Soc. Bull. 26i 1 1:68-75. 

 Fay, F. H., J. J. Burns, S. W. Stoker, and J. S. Grundy. 



1994. The struck-and-lost factor in .Ma.skan walrus 

 harvests. Arctic 47(4 ):.368-373. 

 Fay, F. H., L. L. Eberhardt, B. P. Kelly, J. J. Burns, and 

 L. T. Quakenbush. 



1997. Status of the Pacific walrus population, 19.50-1989. 

 .Mar. Mamm. Sci. 13:537-565. 



Ray. D. J. 



1975. The eskimos of the Bering Strait, 1650-1898. Univ. 

 Washington Press. Seattle, WA, 305 p, 

 Snedecor. G. W., and W. G. Cochran. 



1967. .Statistical methods, sixth ed. The low-a State Univ. 

 Press, Ames, lA, 593 p. 

 Wade, P. R. 



1998. Calculating limits to the allowable human-caused 

 mortality of cetaceans and pinnipeds. Mar. Mamm. Sci. 

 14(ll;l-37. 



Gorbics, C. S.. J. L. Garlich-Miller, and S. L. Schliebe. 1997. 

 Draft Alaska marine mammal stock assessments 1997: sea otter, 

 polar bear and walrus. U.S. Fi.sh and Wildlife Service, Marine 

 Mammals Management, Anchorage, AK. Admin. Report, 129 p. 



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