Results of the 2004 cod ageing exchange
using randomly selected samples from the 2003 DFO spring survey.
(A) Agreement plot, showing the ages attained by the U.S. age readers 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 country'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 readers. Total age frequencies are given by age for both countries. (C) Results summary, indicating results for the U.S. readers relative to each age for the Canadian reader.
2004 U.S./Canada Ageing Exchange
2003 DFO Spring Survey (NED2003002)
NM/NS vs. BH
*The U.S. age readers are listed first; this is not meant to imply that any reader's ages are expected to be more reliable. Both U.S. age readers worked together to age these samples.