Figure 2. Results of cod age-reader precision exercise against randomly selected samples from the 2005 NEFSC autumn bottom trawl survey. (A) Age-bias plot, showing the average age attained during the exercise for fish of each age as determined during production aging. Error bars indicate 95% confidence intervals. (B) Age-frequency table, showing the ages attained during the test exercise across the top and the production ages on the left. Numbers in the shaded boxes indicate agreement between the two ages. Numbers above this diagonal indicate fish which were over-aged during the exercise; those below the shaded boxes were under-aged during the exercise. Total age frequencies are given by age for both the test and production ages.

A.

B. Prod. Age Test Age 0 1 2 3 4 5 6 7 8 9 10 Total 0 2 2 1 4   4 2 8     8 3   12   12 4   10   10 5   2           2 6   6   6 7   1 4       5 8             9       1   1 10             Total 2 4 8 12 10 2 7 4   1   50

to Figure 3