Costs and benefits of a multi-generation captive broodstock Chinook Salmon hatchery program

Objective We evaluated a 19-year captive broodstock hatchery program initiated in 1997 in the White River in central Washington State to contribute to recovery of the upper Columbia River endangered spring Chinook Salmon Oncorhynchus tshawytscha population. Methods Fertilized eggs and fry were collected in the White River and transported to hatcheries in Washington State, where the fish were raised from 1 to 5 years until sexually mature and spawned. The offspring of these matings were reared to the yearling presmolt stage in a hatchery and transported to the White River or Lake Wenatchee for final acclimation and then released into surrounding areas. Results In total, 10,353 eggs and fry were collected for brood, which equated to about three females’ eggs. These were collected from 122 redds between 1998 and 2009 and were used to produce 944,606 smolts. The number of produced adults that returned to Bonneville Dam was 685, but only 61 of those returned to spawn in the White River. The program did not increase natural-origin spawners relative to those observed in unsupplemented control rivers and did not consistently meet a viability standard of 20 redds created by natural-origin spawners. Some reasons for low numbers of captive brood adults returning to the White River included (1) high rates of male precocity, (2) low postrelease survival, and (3) high adult stray rates. Conclusions Although the program produced over 900,000 more smolts and about 52 more adults in the White River than would have been produced if no hatchery intervention occurred, the program did not meet recovery objectives, posed risk to target and nontarget populations, and cost over US$28 million to implement.