Tucannon River Spring Chinook Salmon Captive Broodstock Program: 2005 Annual Report

This report summarizes the objectives, tasks, and accomplishments of the Tucannon River Spring Chinook Captive Broodstock Program during 2005.

The WDFW initiated a captive broodstock program in 1997. The overall goal of the Tucannon River captive broodstock program is for the short-term, and eventually long-term, rebuilding of the Tucannon River spring Chinook salmon population, with the hope that natural production will sustain itself in the future. The project goal is to rear captive salmon selected from the supplementation program to adults, spawn them, rear their progeny, and release approximately 150,000 smolts annually into the Tucannon River between 2003-2007. These smolts, in combination with the current hatchery supplementation program (132,000 smolts) and wild production, are expected to produce 600-700 returning adult spring Chinook to the Tucannon River each year from 2005-2010.

The captive broodstock program collected juvenile hatchery supplementation fish from five (1997-2001) brood years (BY) with additional fish collected from the 2002 BY to have extra males available towards the end of the program. As of January 1, 2006, WDFW had approximately 11 BY 2001 and 90 BY 2002 fish remaining at Lyons Ferry Hatchery.

The 2005 eggtake from the 2001 brood year (Age 4) was 210,296 eggs from 131 ripe females. Egg survival was 34%. Mean fecundity based on the 126 fully spawned females was 1,639 eggs/female.

The 2005 eggtake from the 2002 brood year (Age 3) was 51,549 eggs from 36 ripe females. Egg survival was 62%. Mean fecundity based on the 35 fully spawned fish was 1,436 eggs/female.

The total 2005 eggtake from the captive brood program was 261,845 eggs. A total of 158,033 dead eggs (60%) were removed with 103,812 live eggs remaining for the program. An additional 9,841 dead eggs/fry (9.5%) were picked at ponding leaving 93,971 fish for rearing. As of May 1, 2006 we had 92,611 BY 2005 captive brood progeny on hand.

During April 2006, WDFW volitionally released 132,312 BY 2004 captive broodstock progeny smolts from Curl Lake Acclimation Pond into the Tucannon River. These fish were marked with a CWT only in order to differentiate them from the supplementation fish (CWT/Right Red VIE/No Finclip). One thousand captive brood progeny smolts were PIT tagged to compare their outmigration with smolts from the supplementation program (1,000 tagged). Monitoring their survival and future releases to adult returns, along with future natural production levels, will determine the success or failure of this captive broodstock program.