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.