Grande Ronde Endemic Spring Chinook Salmon Supplementation Project; Lostine River Operations and Maintenance 2006 Smolt Acclimation and Adult Return Report.

Abstract

The Nez Perce Tribe (NPT), through funding provided by the Bonneville Power Administration (BPA), has implemented a Chinook salmon supplementation program (250,000 smolts) on the Lostine River, a tributary to the Grande Ronde River of Oregon. The Grande Ronde Endemic Spring Chinook Salmon Supplementation project, which involves supplementation of the Upper Grande Ronde River and Catherine Creek in addition to the Lostine River, was established to prevent extirpation and increase the number of threatened Snake River spring/summer Chinook salmon (Oncorhynchus tshawytscha) returning to the Grande Ronde River. This report covers the tenth season (1997-2006) of adult Chinook salmon broodstock collection in the Lostine River and the eighth season (1999-2006) of acclimation of resulting Lostine River progeny. Production of Lostine River spring Chinook salmon smolts currently occurs at Lookingglass Fish Hatchery (LGH). The Lostine River supplementation program utilizes two strategies to obtain egg source for production of smolts for supplementation: captive broodstock and conventional broodstock. The captive broodstock strategy involves (1) capture of natural juvenile spring Chinook salmon smolts from the Lostine River, (2) rearing those to adult and spawning them, and (3) rearing the resultant progeny for eventual acclimation and release back into the Lostine River. The conventional broodstock strategy involves (1) capture of natural and hatchery origin adults returning to the Lostine River, (2) holding those adults and spawning them, and (3) rearing the resultant progeny for acclimation and release back into the Lostine River. This report focuses on (1) the trapping and collection of adult spring Chinook salmon that return to the Lostine River, which provides the broodstock source for the conventional strategy and (2) the acclimation and release of juvenile spring Chinook salmon produced from the captive broodstock and conventional broodstock strategies In 2006, acclimation of Lostine River spring Chinook salmon smolts occurred from February 27, 2006 through to April 10, 2006 and a total of 240,568 smolts were acclimated and released. These smolts were produced from the brood year (BY) 2004 egg source and included captive brood (40,982) and conventional (199,586) origin smolts that were all progeny of Lostine River spring Chinook salmon. Operation of the Lostine River adult monitoring and collection facility in 2006 began May 15th, the first Chinook was captured on June 14, 2006 and the last Chinook was captured on September 27, 2006. The weir and trap were removed on October 1, 2006. A total of 534 adult Chinook, including jacks, were captured during the season. The composition of the run included 205 natural origin fish and 329 hatchery supplementation fish. There were no identified 'stray' hatchery fish from other programs trapped. Of the fish captured, 33 natural and 120 hatchery supplementation adults were retained for broodstock and transported to LGH for holding and spawning and 397 adult Chinook were passed or transported above the weir to spawn naturally. In 2006, no hatchery origin adult Chinook were transported and out planted in the Wallowa River and Bear Creek to spawn in under seeded habitat. In order to meet egg take goals for the conventional portion of the program, a determination was made that approximately 147 adults were needed for broodstock. As a result 16 (8 males and 8 females) of the 153 fish collected for broodstock were returned to the Lostine River to spawn naturally. Females that were spawned and provided the brood source were made up of 12 natural females and 45 supplementation females. One of these females tested positive for high levels of Bacterial Kidney Disease and consequently this females eggs were destroyed. The remaining females produced a total of 241,372 eggs at fertilization. Eye-up was 85.47% which yielded a total of 206,309 conventional program eyed eggs. The fecundity averaged 4,162 eggs per female. The brood year 2006 eggs will be incubated and reared at Lookingglass Hatchery until they are smolts in the spring of 2008. Captive brood program eggs/fish will be added to the conventional program eggs to make up the entire juvenile release for the Lostine River program in 2008.