Observations on reared newly released and wild cod (Gadusmorhua L.) and their potential predators

Comparisons are made between the stomach contents and liver weights of reared newly released cod and wild cod; the stomach contents and abundance of potential predators are described. Reared cod were stocked within a bay of a fjord and fishing was conducted before and after release to capture wild and reared juvenile cod and their potential predators. During the first three days after release, the reared cod fed mainly on non-evasive prey of Gastropoda. Bivalves, and Actinaria. This is in contrast to wild juvenile cod, which mainly fed on Gobiidae. Brachyura, and Mysidacea. The liver weight of the reared and newly released fish was significantly higher than that of wild fish. Large cod. pollack, and ling preyed upon the released cod immediately after their release, whereas during the months following release the stomach contents of large predators were dominated by Labridae and Salmonidae. The abundance of predators did not seem to increase within the area of release.

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