Goodyear: Fish age from length: an evaluation of three methods 
41 
samples per year. No error was added to either age or 
length to simulate measurement error. 
The ages of the first two fish sampled in each 1-cm 
length stratum each month were retained with their 
lengths to build the age-length key for that month. 
This provided a maximum sample size of 24 fish per 
length stratum or about 4,000 fish per year to con- 
struct the age-length key, but sample size varied 
slightly because of the stochastic nature of the sam- 
pling process. 
