Brood Year 2004: Johnson Creek Chinook Salmon Supplementation Report, June 2004 through March 2006

摘要

The Nez Perce Tribe, through funding provided by the Bonneville Power Administration, has implemented a small scale chinook salmon supplementation program on Johnson Creek, a tributary in the South Fork of the Salmon River, Idaho. The Johnson Creek Artificial Propagation Enhancement project was established to enhance the number of threatened Snake River spring/summer chinook salmon (Oncorhynchus tshawytscha) returning to Johnson Creek to spawn through artificial propagation. This was the sixth season of adult chinook broodstock collection in Johnson Creek following collections in 1998, 2000, 2001, 2002, and 2003. Weir installation was completed on June 21, 2004 with the first chinook captured on June 22, 2004 and the last fish captured on September 6, 2004. The weir was removed on September 18, 2004. A total of 338 adult chinook, including jacks, were captured during the season. Of these, 211 were of natural origin, 111 were hatchery origin Johnson Creek supplementation fish, and 16 were adipose fin clipped fish from other hatchery operations and therefore strays into Johnson Creek. Over the course of the run, 57 natural origin Johnson Creek adult chinook were retained for broodstock, transported to the South Fork Salmon River adult holding and spawning facility and held until spawned. The remaining natural origin Johnson Creek fish along with all the Johnson Creek supplementation fish were released upstream of the weir to spawn naturally. Twenty-seven Johnson Creek females were artificially spawned with 25 Johnson Creek males. Four females were diagnosed with high bacterial kidney disease levels resulting in their eggs being culled. The 27 females produced 116,598 green eggs, 16,531 green eggs were culled, with an average eye-up rate of 90.6% resulting in 90,647 eyed eggs. Juvenile fish were reared indoors at the McCall Fish Hatchery until November 2005 and then transferred to the outdoor rearing facilities during the Visual Implant Elastomer tagging operation. These fish continued rearing in the outdoor collection basin until release in March 2006. All of these fish were marked with Coded Wire Tags and Visual Implant Elastomer tags. In addition 12,056 of the smolts released were also tagged with Passive Integrated Transponder tags. Hand counts provided by marking crews were used to amend the number of juvenile salmon released from the original egg count. A total of 90,450 smolts were released directly into Johnson Creek on March 13 through 15, 2006.