| A B S T R A C T
Spring Chinook Salmon Reintroduction in the Walla Walla
River
| Spring
Chinook were extirpated from the Walla Walla River more than eighty
years ago. The Confederated Tribes of the Umatilla Indian Reservation
is working to restore the subsistence, economic, religious and cultural
values of salmon. This is being accomplished by working with, not
against, the local community to cooperatively identify improvements
and funding necessary for reestablishing salmon runs in the Walla
Walla River. Our monitoring and evaluation thesis is that Reintroduced
Carson Stock spring Chinook can spawn, rear, migrate, and return to
the Walla Walla River. Our monitoring objective is to describe “Adults-
in” and “Juveniles-out” a measure of spring Chinook
viability. Our monitoring goal is to provide status and trend information
for the Tribes’ Walla Walla Spring Chinook Reintroduction Program.
Our primary performance measures for Adults-in are adult escapement,
recruits per spawner, redd counts, and fish per redd. Our primary
performance measures for Juveniles-out are Smolt to Adult return,
outmigrant survival (Cormack-Jolly-Seber) and run timing to McNary
Dam. While we continue to evaluate production capacity, we believe
our initial program results suggest that spring Chinook can spawn
rear and return to the Walla Walla River. Adult Spring Chinook returns
back to the upper Walla Walla River and Mill Creek have increased
from about 200 in 2004 (the first year of returns) to almost 800 in
2009. Since 2000, Spring Chinook recruit per spawner has averaged
roughly 0.5. Adult replacement was reached for the first time in 2009,
for the partial brood year 2005 return. Since 2002, overall mean smolt
to adult return for natural spring Chinook from release at the traps
to adult return at Bonneville Dam was 0.30 percent; likewise, since
2005 overall mean survival to Bonneville for hatchery smolts slightly
lower at 0.25 percent. In the future, onsite hatchery acclimation
and volitional release may help us meet our production goals. |
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