Extended Freshwater Rearing of Pink Salmon at a Washington Hatchery

Abstract

Many fish culturists believe that after incubation and 45 days of fresh water rearing, smolts of pink salmon (Oncorhynchus gorbuscha) must then be further reared at salinities of 15 to 25 ‰ until they are stocked. We monitored the rearing of 50,000 pink salmon of the 1971 brood in fresh water for 135 days. At release the average weight of the fish was 12.4 g (81 fish/kg) and the average fork length, 122 mm; average condition factor was 1.1. A substantial number of these salmon returned to the release site in 1973.