A tagging and release experiment of 2-group artificially reared coastal cod (Gadus morhua). In: Flødevigen rapportserie no 1, 1990

Abstract

Cod were raised in an outdoor enclosure for the first 3 months after hatching and then transferred to the laboratory. After 2 years and at a length range from 33 to 52 cm (0.3 kg to 1.3 kg), 68 cod were tagged and released in the Flødevigen Bay area. Of these cod, 29% were reported recaptured and most of these (65%) were fished not more than 5 km from the place of release. The results indicated that the fish disperse quickly within the area after release, with one moving about 5 km within one day. The fish dispersed in both directions along the coast, moving a maximum of 30 km in each direction. Of the fish recaptured. 50% were reported within 30 days and 75% within 100 days. No recapture was reported later than 16 months after the release. Released cod tend to migrate little, aithough these cod (33-52 cm) dispersed over a wider area than did smailer cod (7- 17 cm) in previous release experiments in the same area. The recapture rate indicates that releasing artificially reared cod for later harvesting of market size cod (minimum 1.5 kg), will not be economically profitable.