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To facilitate intercalibration of the age readings of ling, blue ling and tusk, series of otoliths were exchanged among the fisheries laboratories in Iceland, the Faroes and Norway. For ling and tusk, the precision was significantly improved by the exchange exercises, but remained relatively low. Many large specimens could not be aged with confidence, 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 patterns should be accepted as annuli. The age readings from otoliths of 1-2 group tusk and blue ling corresponded well with assumed ages based on modes in the lengthfrequency distributions from Icelandic groundfish surveys.

Hepatic levels of mercury, cadmium, lead, and selenium and levels of mercury and selenium in muscle tissue were analysed in tusk from the Nordfjord in Norway. With the exception of selenium in the muscle tissue, the metal levels were significantly higher in the fjord fish than in fish caught off the coast. No local source is known to explain the difference in levels, and this indicates that the fjord efficiently accumulates atmospheric contaminants. The present results demonstrate the importance of sampling area when determining levels of metals in marine organisms far from point sources. The liver was increasingly used as a storage compartment for mercury and selenium with increasing exposure.

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