Figure 1. Results of cod age-reader accuracy exercise against randomly selected samples from the NEFSC cod reference collection. (A) Age-bias plot, showing the average age attained during the exercise for fish of each age from the reference collection. Error bars indicate 95% confidence intervals. (B) Age-frequency table, showing the ages attained during the test exercise across the top and the reference ages on the left. Numbers in the shaded boxes indicate agreement between the two ages. Numbers above this diagonal indicate fish which were overaged 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 reference ages.

A.

B. Ref. Age Test Age 0 1 2 3 4 5 6 7 8 Total 0     1       2 11 4 1 16 3   11   11 4   8   8 5   4 1     5 6   4   4 7     1   1 8         Total     11 15 9 4 5 1   45