INTERCALIBRATION OF AGE READINGS OF LING (MOLVA-MOLVA L.) BLUE LING (MOLVA-DIPTERYGIA PENNANT, 1784) AND TUSK (BROSME BROSME L.)

To facilitate intercalibration of the age readings of ling, blue ling and tusk, series of otoliths were exchanged among the fisheries labora tories in Iceland, the Faroes and Norway. For ling and tusk, the preci sion was significantly improved by the exchange exercises, but remaine d relatively low. Many large specimens could not be aged with confiden ce, and for tusk of all sizes a rather high proportion of the otoliths were unreadable. For blue ling, some progress was made using otolith sections of juvenile fish, but it remained difficult to decide what pa tterns should be accepted as annuli. The age readings from otoliths of 1-2 group tusk and blue ling corresponded well with assumed ages base d on modes in the length-frequency distributions from Icelandic ground fish surveys. (C) 1998 International Council for the Exploration of th e Sea.