This report summarizes
the objectives, tasks, and accomplishments of the Tucannon River Spring
Chinook Captive Broodstock Program during 2002.
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
run, 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 smolt releases, 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). As
of January 1, 2003, WDFW has approximately 11 BY 1998, 194 BY 1999,
314 BY 2000, 447 BY 2001, and 300 BY 2002 (for extra males) fish on
hand at LFH.
The 2002 eggtake
from the 1997 brood year (Age 5) was 13,176 eggs from 10 ripe females.
Egg survival was 22%. Mean fecundity based on the 5 fully spawned
females was 1,803 eggs/female.
The 2002 eggtake
from the 1998 brood year (Age 4) was 143,709 eggs from 93 ripe females.
Egg survival was 29%. Mean fecundity based on the 81 fully spawned
females was 1,650 eggs/female.
The 2002 eggtake
from the 1999 brood year (Age 3) was 19,659 eggs from 18 ripe females.
Egg survival was 55%. Mean fecundity based on the 18 fully spawned
fish was 1,092 eggs/female.
The total 2002
eggtake from the captive brood program was 176,544 eggs. A total of
120,833 dead eggs (68%) were removed with 55,711 live eggs remaining
for the program. As of May 1, 2003 we had 46,417 BY 2002 captive brood
progeny on hand.
A total of 20,592
excess BY 01 fish were marked as parr (AD/CWT) and released during
May 2002 into the Tucannon River (rkm 40-45). This allowed us to stay
within our maximum allowed number (150,000) of smolts released.
On August 20,
97 (21 1998 BY and 76 1999 BY) adult captive broodstock were determined
to be in excess of eggtake goals and were outplanted into the Tucannon
River at Panjab Bridge (rkm 74.5). Released fish were tagged with
Monel jaw tags and radio transmitters were inserted into ten females
for tracking and monitoring.
Due to the low
frequency of natural spawning by released fish, high mortality due
to predation and illegal harvest, and high egg mortality in the hatchery
during 2002, priority will be to release excess progeny as parr to
stay within smolt release goals rather than release excess captive
broodstock as adults.
During April
2003, WDFW volitionally released 140,396 BY 2001 captive broodstock
progeny smolts from Curl Lake Acclimation Pond into the Tucannon River.
These fish were marked with agency-only wire tags and no fin clips
in order to differentiate them from the supplementation fish (CWT/Right
Red VIE/No Finclip). A total of 1,007 captive brood progeny smolts
were PIT tagged to compare their outmigration with smolts from the
supplementation program (1,010 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.
