1044 



Fishery Bulletin 97(4), 1999 



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Figure 1 



Location of Alaska villages where walrus harvest information is collected through the Walrus Harvest 

 Monitor Project (O) and the Marking Tagging and Reporting Program (•:. Note that tusks may be 

 tagged in selected locations outside the walrus' range. 



Owing to funding and logistical constraints that 

 prevent the year-round, statewide implementation 

 of the WHMP and imperfect hunter compliance with 

 the MTRP, not all harvested walruses are recorded. 

 The FWS must therefore rely on analytical methods 

 to estimate the size of the total annual harvest based 

 on the best available information. Here we describe 

 a new method for estimating the size of the annual 

 walrus harvest in Alaska using a correction factor 

 for noncompliance with the MTRP rule. 



Materials and methods 



Prior to the initiation of the MTRP, the statewide 

 walrus harvest was approximated by using a predic- 

 tion equation applied to WHMP data. The predic- 

 tion equation was based upon the historic relation- 

 ship of the size of the spring harvest at WHMP-moni- 

 tored villages in relation to the remaining hunting 

 villages in Alaska. This information was obtained 

 from the Alaska Department of Fish and Game, 

 which administered a statewide harvest monitoring 

 program between the years of 1960 and 1978. To es- 

 timate the statewide harvest, the FWS used a least- 

 squares regression to describe the relation between 

 the Gambell, Savoonga, and Diomede harvests to the 

 statewide totals. The resulting prediction equation 



(Equation 1, /•2=0.239) was subsequently used to es- 

 timate the total statewide harvest on the basis of 

 data collected annually after 1978 through the 

 WHMP at Gambell, Savoonga, and Diomede. 



A^ = 459.7 + 1.26 ( WHMP7-„,„,), 



(2) 



where 

 WHMP 



Total 



N = total statewide harvest estimate; and 

 - total number of retrieved walruses re- 

 corded during monitored 

 spring hunts at select villages 

 (Diomede, Gambell, and Savo- 

 onga) for a given year. 



The evolution of the MTRP as a year-round, state- 

 wide monitoring program provided the opportunity 

 to improve the reliability of harvest estimates by 

 using current data. Because there is spatial and tem- 

 poral overlap between the two programs, the WHMP 

 can serve as a baseline for evaluating compliance 

 with the MTRP program. A correction factor for non- 

 compliance can be estimated as a proportion by us- 

 ing the following equation: 



R 



WHMP, 



Total 



MTRP,y„!^p 



(2) 



i 



