FISHERY BULLETIN: VOL. 74, NO. 3 



B = 



(2e^'^ - 1) (^rf J 



(7) 



An estimate of L is obtained from an iterative 

 solution of E(iuation (6). An estimate of the 

 minimum value of B is obtained from substitution 

 of the estimate of L into Equation (7). Our es- 

 timate of L and the minimum value of B, where 

 only returns with specified dates are included in 

 the calculations, are 0.087 and 0.78, respectively. 

 When all of the return dates are included we 

 estimate L to be 0.077 and B to be 0.78. Thus, it 

 appears that the rate of reporting double-tag 

 recoveries as single-tag recoveries is less than 0.22 

 (\-B). 



However, we have no evidence to indicate that 

 fishers have returned only one tag from fish 

 recovered with two tags. We believe that fishers 

 have turned in both tags of fish recovered with two 

 tags based on interviews with those who have 

 recovered tagged fish, the very good cooperation 

 that we have received from them during the 

 tagging program, and the fact that tags from 

 recovered fish may be returned to the fisher if he 

 wishes to have them. 



ACKNOWLEDGMENTS 



We thank the skippers, crewmen, and NMFS 

 technicians who participated in the albacore tag- 

 ging and release program; members of AFRF for 



supporting the tagging charters; albacore fishers 

 and fish processors for their excellent cooperation 

 in reporting tag recoveries. We also thank R. 

 Francis of the Inter-American Tropical Tuna 

 Commission, J. Wetherall of the Southwest Fish- 

 eries Center Honolulu Laboratory, and J. Zweifel 

 of the Southwest Fisheries Center La Jolla 

 Laboratory, for critically reviewing the paper. J. 

 Wetherall and M. Yong have developed maximum 

 likelihood estimators of the variance of p, L, and B 

 and intend to publish their work. 



LITERATURE CITED 



B.WLIFF, W. H.. .AND L. M. MOBR.\ND. 



1972. E.stimates of the rates of shedding of dart tags from 

 yellowtin tuna. [In Engl, and Span.] Inter-Am. Trop. 

 Tuna Comm., Bull. 15:441-462. 



Chapman, D. G., B. D. Fink, and E. B. Bennett. 



1965. A method for estimating the rate of shedding of tags 

 from yellowfin tuna. [In Engl, and Span.] Inter-Am. 

 Trop. Tuna Comm., Bull. 10:333-352. 

 Fink. B. D. 



1965. A technique, and the equipment used, for tagging 

 tunas caught by the pole and line method. J. Cons. 

 29:335-339. 

 Lenarz, W. H., F. J. Mather III, J. S. Beckett, A. C. Jones, and 

 J. M. Mason, Jr. 



1973. Estimation of rates of tag shedding by northwest 

 Atlantic bluefin tuna. Fish. Bull., U.S. 71:1103-1105. 



Yamashita, D. T., and K. D. Waldron. 



1958. An all-plastic dart-type fish tag. Calif. Fish Game 

 44:311-317. 



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