Investigations on Pelagic Fry of Cod and Haddock in Coastal and Offshore Areas of Northern Norway in July-August 1957
Abstract
In July-August 1957 the distribution of pelagic cod and haddock
of the O-group was investigated in the coastal and offshore waters of
northern Norway. The cod was most abundant near the coast, the haddock
also numerous farther offshore, and usually outnumbered the cod.
The cod measured 30-90 mm, the average lengths increasing from
53-55 mm in July to 65 mm in August. Cod, taken in a purse seine off
Andenes in July, measured 50-85 mm.
The haddock measured 30-110 mm, the average lengths increasing
during the cruise from 62 mm to 92 mm. Purse seined haddock measured
80-110 mm.
Copepods were most important as food both for cod and haddock,
Calanus finmarchicus ranging first. The other food components were of
varying significance in the two fishes. The cod had eaten krill and appendicularians
to a great extent, locally also Limacina, cladocerans, amphipods
and fish fry. The larger cod taken in the purse seine, had mainly
taken fry of redfish and herring, and krill.
In the haddock, appendicularians, Limacina and Clione were generally
of greater importance than in the cod, whereas krill had been eaten to
a much smaller extent. Locally, medusae played a great part in the diet.
Limacina was found in 80 per cent of the stoimachs of the haddock taken
in purse seine, while krill and herring fry were met with in only 20 and
7 per cent respectively.
A comparison of the food organisms with those taken in simultaneous
plankton hauls indicates that the fish to a certain extent select their food,
partly that the food organisms may occur in swarms in the plankton.
Publisher
[Fiskeridirektoratets havforskningsinstitutt]Series
Fiskeridirektoratets skrifter, Serie Havundersøkelservol 12 no 8