the Tailout May 2020 tailout_may2020finalx | Page 14

A winter-run chinook salmon.
nia’s severe drought. That left few
juvenile fish to migrate to the ocean
in those years and return as adults to
spawn.
Biologists took the emergency
action of supplementing the critical-
ly low numbers by releasing about
600,000 juvenile winter-run chinook
salmon in 2014, and 400,000 in 2015.
They were released from the U.S.
Fish and Wildlife Service’s Livingston
Stone National Fish Hatchery. Biol-
ogists felt the need to balance against
the risk of the population becoming
dependent on hatcheries for its sur-
vival. In this case, it turned out to be
a lifeline for the endangered species,
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SALMON
& STEELHEAD JOURNAL
THE TAILOUT
boosting the numbers of returning fish
enough to outlast the drought.
The parents of this 2019’s juveniles
went to sea in 2016 and early 2017 as
the drought was waning and condi-
tions were improving.
The Livingston Stone hatchery
also revived its captive broodstock
program, raising some winter-run
chinook salmon to adulthood and
then transferring their offspring to
Coleman National Fish Hatchery.
Biologists used the additional juve-
niles to jumpstart the reintroduction
of winter-run chinook salmon to
their historic habitat in Battle Creek.
Almost 100 of those fish released as
juveniles returned to Battle Creek as
adults this year, underscoring rein-
troduction as an effective recovery
strategy.
Biologists are tracking the propor-
tion of hatchery fish among the re-
turning adults to address the potential
risk to the winter-run population.
“We were fortunate to have the
hatchery to help us save this species,
and two years of wet weather winter
flow conditions made an important
difference too,” Rea said. “We now
need to stay focused on our priori-
ty conservation measures, such as
habitat, to stabilize and recover the
population in the long run.”