Iron Gate Hatchery won't
release fish into Klamath River
and News by Alex Schwartz 7/10/21
for the first time in its 55-year history, Iron Gate Fish
Hatchery will not release young salmon into the Klamath
management cited the river’s exceptionally poor water
quality and heightened fish disease risk as reasons for
keeping hatchery smolts in captivity until conditions
improve in the fall.
Over the past
two weeks, the California Department of Fish and Wildlife
has trucked more than a million smolts to two other
hatcheries in the Klamath watershed, where they will
continue to be looked after through the remainder of the
summer. Once the Klamath River cools and the threat of
salmon disease wanes, CDFW will return them to Iron Gate and
decision comes on the heels of a staggering juvenile fish
kill on the mainstem
Klamath River that began in May. At one point, as many as
97% of sample salmon captured by fishery biologists from the
Yurok Tribe were infected with the parasite C.
shasta, and many of them were already dead.
normally releases its smolts in the early summer, which in
many years has coincided almost perfectly with the parasite
outbreak. The fish swim right through the infectious zone
below Iron Gate Dam, picking up C.
shasta spores released by massive colonies of annelid
worms that carpet the riverbed. Salmon disease specialists
have long bemoaned the practice, which can actually
exacerbate the outbreak by providing the parasite with more
fish hosts to infect.
however, the hatchery has responded to the river’s severe
drought conditions by waiting to release the fish.
“It really was
the best idea to just not release the hatchery fish into the
river system, because it would’ve been almost futile,” said
Mark Clifford, an environmental scientist with CDFW.
Clifford said a
salmon migration model run by the U.S. Fish and Wildlife
Service, which takes into account the river’s temperature
and the number of C.
shasta spores present per liter of water, predicted
high mortality for the hatchery fish if they were released
according to normal protocol.
estimating the survivability of some fish, and it wasn’t
good,” he said.
But because the
smolts will only grow as the summer progresses, Iron Gate
Hatchery will soon run out of space to comfortably fit the
more than 2 million fish that had been spawned last winter.
Water quality would decrease, spelling trouble for fish
health. To fix that, CDFW is sending a little over half
those fish to summer camp.
surprisingly smoke-free morning this Wednesday, a truck
pulled up next to one of the hatchery’s ponds. A cloud of
tiny, gray salmon swirled around in the water as hatchery
staff turned on a pump to draw them into the truck’s
insulated tank. The translucent pipe showed outlines of the
assumedly confused baby salmon as they rose into a funnel,
which dropped them into a separate pipe feeding the tank.
After more than 20,000 fish had amassed on the truck, the
Then the fish
were taken on a quick road trip along the northern shore of
Iron Gate Reservoir, where no salmon have swum for more than
half a century.
backed up to a pond at the rustic Fall Creek Hatchery,
originally built in 1919. Drawing from a consistently cool,
oxygenated tributary to the Klamath, the hatchery was
originally built to mitigate the impacts of the Copco No. 1
dam and ceased to be useful in 1965, when Iron Gate Dam
blocked salmon from reaching it. Between the 1970s and the
early 2000s, CDFW raised additional fish there for fishery
Hatchery has awoken from an 18-year slumber to host what’s
expected to be the first generation of salmon that will
explore this area after four hydroelectric dams on the
Klamath River are removed in 2023.
“It has an
excellent water supply, and that’s why we’re utilizing it,”
Clifford said. “It’s very dependable.”
consortium of scientists, tribes and federal agencies met to
decide what to do about this year’s hatchery fish, Clifford
said an idea was floated to truck the smolts all the way
down to the Lower Klamath River past the infectious zone,
essentially completing the migration to the ocean for them.
That’s been done on the Sacramento River during drought
years like this one.
said there was a concern that the returning adults would
then stray into the Klamath’s tributaries, like the Salmon
and Shasta Rivers, which are known for their genetically
distinct populations, and cause unwanted genetic exchange
during spawning. Thus, they’d still need to enter the river
at Iron Gate to ensure they’d return there to spawn.
“The fish home
in on the chemical signature of the water,” Clifford said.
All in all, a
million smolts will spend the summer at Iron Gate Hatchery,
while 170,000 are being transferred to Fall Creek. CDFW
trucked another million fish to Trinity Hatchery last week —
a winding, three-hour drive through record heat which went
“We didn’t lose
hardly any,” Clifford said.
As the summer
heat begins to subside, the travelers will return to Iron
Gate Hatchery to spend a few weeks getting used to its water
before the raceway gates will open and they begin their
journeys to the ocean. Clifford said they’ll have the extra
advantage of being a little older and hardier, allowing them
to better handle stressors the river throws at them.
“Maybe we get
some good storms in October, but we want basically more
flow, colder temperatures, more oxygen, less infective
stages of the pathogen,” Clifford said.
News of the
hatchery operations change was music to C.
shasta expert Sascha Hallett’s ears. The Oregon State
University associate professor said she’s been encouraged in
recent years by the hatchery releasing fish in conjunction
with a flow event, and that delaying the release until the
fall will likely give the smolts a better chance of
year I’d shake my head going, ‘Why are they letting those
fish out now? It’s hot, and there’s parasite. This doesn’t
make any sense,’” she said. “This reflects the increased
communication that I’ve witnessed between all the different
groups, and the hatcheries not just following the formula as
such. They are really incorporating real-time information
about the basin and modifying operations accordingly.”
that the hatchery is trying to be flexible to river
conditions, despite the more complicated logistics required
to do so. He said the operations will likely be more in tune
with what’s happening on the ground (or in the water) in the
“We adapt to
meet the conditions,” he said. “It could be a flood, it
could be a drought, it could be a fire.”
she would’ve expected more than half the hatchery smolts to
die in the river had they been released in the summer, based
on water quality conditions and the scale of this year’s C.
shasta outbreak. Now they’ll have more of a chance of
surviving to potentially repopulate the reservoir reaches
after dam removal.
“This is a
positive action, but it just highlights that the conditions
in the Klamath this year are so severe,” she said.
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