Department of Fisheries Resources Management
Grande Ronde Supplementation/ Lostine Monitoring & Evaluation Project

Historically, the Lostine River was one of many streams that supported a healthy run of Snake River Chinook salmon within the boundaries of the 1855 treaty between the United States and the Nez Perce Tribe. However, the population of Snake River Chinook salmon had declined so severely that they were listed as “threatened” in 1992 under the Endangered Species Act.

Efforts to restore Chinook salmon in the Lostine River and other Grande Ronde River tributaries began in 1994 as a joint effort between the Nez Perce Tribe, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Dept. of Fish and Wildlife, and the United States Fish and Wildlife Service. One of the primary strategies for restoration is supplementation. Supplementation is an effort to use artificial production to rebuild populations to self sustaining levels. The Nez Perce Tribe began collecting natural Chinook salmon parr for a captive broodstock program in 1995 and initiated a conventional program in 1997. These two strategies form the basis of the supplementation efforts in the Lostine River.

The first release of 11,378 juvenile Lostine River hatchery Chinook salmon occurred in 1999. As of 2006, the Tribe has released over 1,180,000 Lostine origin juveniles to the Lostine River. Hatchery Chinook salmon adults first began returning in 2000. Adult returns, or escapement, to the Lostine River weir from 2000 to 2005 is estimated to have ranged from 410 adult Chinook salmon in 2000 to 1,556 adult Chinook salmon in 2004. Brood year 1997 to 2000 smolt-to-adult return rates are estimated to have ranged from 0.23% for brood year 1999 to 2.07% for brood year 1997.

Ongoing monitoring and evaluation will continue to estimate adult escapement and will determine spawning distribution of female natural and hatchery Chinook salmon, as well as the relative reproductive success of natural and hatchery origin Chinook salmon through DNA fingerprinting studies.

Publications:
Evaluation of Spring Chinook Salmon (Oncorhynchus tshawytscha) Supplementation in the Lostine River, 1997-2004.