Results of the 2004 haddock ageing exchange
using randomly selected samples from the 2003 DFO spring survey.
(A) Agreement plot, showing the ages attained by the U.S. age reader versus the ages attained by the Canadian age reader. A small amount of noise was added to the data to improve visibility of overlapping data points. (B) Age-frequency table, showing each reader's ages. Numbers in the shaded boxes indicate agreement between the two ages. Numbers above this diagonal indicate fish which were given higher ages by the Canadian age reader; those below the shaded boxes were given higher ages by the U.S. age reader. Total age frequencies are given by age for both readers. (C) Results summary, indicating results for the U.S. reader relative to each age for the Canadian reader.
2004 U.S./Canada Ageing Exchange
2003 DFO Spring Survey (NED2003002)
NM² vs. LVE
P = 0.035
*The U.S. age reader is listed first; this is not meant to imply that either reader's ages are expected to be more reliable.
²Both U.S. age readers aged these fish separately, and they disagreed on some samples. Therefore, the results for each reader are presented separately.