216 
Fishery Bulletin 109(2) 
• T 5 
1=1 e" 
y,i y,i 
(16) 
% = V v e K 
(17) 
where R* ~ N(0,a 2 R ) , I 5 iy ~ N(0,af) , and ^ ~ N(0,a*). 
Age-composition data are subject to multinomial sam- 
pling errors with a fixed number of aged fish in) for all 
years: 
n} (18) 
( 19 ) 
