Tucannon River Spring Chinook Salmon Captive Broodstock Program: 2004 Annual Report

This report summarizes the objectives, tasks, and accomplishments of the Tucannon River Spring Chinook Captive Broodstock Program during 2004.

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. 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 fish from five (1997-2001) brood years (BY) with additional fish collected from the 2002 BY to have extra males on hand towards the end of the program. As of January 1, 2005, WDFW had approximately 4 BY 2000, 191 BY 2001, and 186 BY 2002 fish on hand at LFH.

The 2004 eggtake from the 1999 brood year (Age 5) was 9,768 eggs from eight ripe females. Egg survival was 47%. Mean fecundity based on the five fully spawned females was 1,490 eggs/female.

The 2004 eggtake from the 2000 brood year (Age 4) was 265,270 eggs from 169 ripe females. Egg survival was 48%. Mean fecundity based on the 163 fully spawned females was 1,598 eggs/female.

The 2004 eggtake from the 2001 brood year (Age 3) was 35,781 eggs from 28 ripe females. Egg survival was 75%. Mean fecundity based on the 28 fully spawned fish was 1,278 eggs/female.

The total 2004 eggtake from the captive brood program was 310,819 eggs. A total of 151,917 dead eggs (49%) were removed with 158,902 live eggs remaining for the program. An additional 18,028 dead eggs/fry (11.3%) were picked at ponding leaving 140,874 fish for rearing. As of May 1, 2005 we had 136,749 BY 2004 captive brood progeny on hand.

During April 2005, WDFW volitionally released 130,064 BY 2003 captive broodstock progeny smolts from Curl Lake Acclimation Pond into the Tucannon River. These fish were marked with a CWT and no fin clips 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.