REPORT OF THE WORKSHOP ON TRAWL SURVEY ... - FAO.org

2
XSA Mean Z (2-5)
Total mortality Z
1
0
1975 1980 1985 1990 1995 2000 2005
Year
Fig. 13.
North sea haddock : Negative gradients of log-abundance per cohort for each
of the three surveys for the age-ranges specified for each survey (i.e. indices of
total mortality Z). The bottom right-hand plot gives comparable values from
the final XSA assessment as average total mortality (M+F) for ages 2-5 by
cohort.
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