The marine survival and growth of wild and hatchery‐reared Atlantic salmon

摘要: Summary 1 Catches of Atlantic salmon Salmo salar L. decreased in the 1980s and 1990s over its entire area North smolts were often released for stock enhancement. However, there are questions about their survival performance relative to fully wild fish. This paper reports on sea growth River Imsa from 1981 1999 as 1- 2-year-old hatchery smolts. 2 Survival was significantly higher than Hatchery had lower survival, captured more coastal freshwaters, grew slowly attained maturity younger corresponding 1-year-old smolts. 3 The rate fish smolts, but not 1-year-olds during 1990s. Growth rates at sea, adult size proportion multi-sea-winter all three groups also time. 4 Catches freshwaters two- one-sea-winter Salmon water greater length those rivers. Mean specific similar 2-year-olds. 5 The two-sea-winter correlated positively with first year sea. Total capture rivers Norwegian home waters each The same correlation held 2- smolts. 6 Synthesis applications. fishery size-selective reducing age salmon. Releases financially profitable 2-year-olds. Decreasing production since chiefly caused by reduced sea-age both A counteracting measure would be reduce selectivity fisheries.