648 



Fishery Bulletin 100(3) 



Errata 



Erratum 1 



Fishery Bulletin 100(2): 242. 



Kitada, Shuichi, and Kiyoshi Tezuka. 



Longitudinal logbook survey designs for estimating 

 recreational fishery catch, with application to ayu 

 (Plecoglosssus altivelis) 



Please note that in the printed copies some equations in 

 Appendix 1 and Appendix 2 incorrectly show carets over 

 the word "Gov." 



Appendix 1 and Appendix 2 (page 242) should read as 

 follows: 



Appendix 1 : The covariance of two estimators from 

 sample means 



First we consider the covariance of two total estimates. 

 LetX, and F, be simple random samples (i=l, . . . , n) from 

 a population of size N with mean //^ and n , and X and Y 

 be two sample means. 



Cochran (1977, p .25) derived the covariance of two- 

 sample mean, that is 



Cov(Z, F ) = ^^^^— ^ - Cov( X, y ) 



N n 



This is estimated by 



Cov(x,y) = ^^^^-Cov(x,y) 



A^ n 

 N 

 Nn{ 



N - n -^ — — 



— —y{X-X){Y-Y) 



The covariance between two population total estimators 

 is defined by 



Cov{X,Y) = Cov{NX,NY) = EiNX - Nfi^ KiVY - Nfi^} 

 = N-Cov{X,Y) = ^'^'"' cov(X,y). 



For the monthly total catches, we get 



Cov(Cr',C-') = ^^^i^X(C„-C,)(C„.-C,, 



n(n-l) -'-' 



1=1 



Appendix 2: Approximate covariance between W^^' 



and Wl'.> 



Taylor's series of W(, with respect to the random variables 

 is obtained by 



From Taylor's series (mentioned above), the approximate 

 covariance is obtained. 



Cov(W;"",Wj'.^') = E(Wl"-Wl")(Wir-Wl?') 

 = £k(Cr'-Cr') + Cr'(i' 



[sr,,(cif'-c;:')+c;f'(EZF,.-iz^,.)] 



Here C'f and w, , are independent, and both u'k and a'*. are 

 estimated from different samples. Therefore Gov iC[^,'wi,. ) = 

 Coviw^.O^'^) = Cov(Wi,,Wt) = 0, then we get the covariance 

 as only the first term. 



Erratum 2 



Fishery Bulletin 100 (2):2S8. 



McFee, Wayne E., and Sally R. Hopkins-Murphy 



Bottlenose dolphin (Tursiops truncatus) strandings in 

 South Carolina, 1992-1996 



Last sentence of abstract should read as follows: 



Incidents of bottlenose dolphin rope entanglements 

 accounted for 16 of these cases. 



This is estimated by 



crv(i,y) = i^^i^^^^y,x,-Z)(y-y 



