Most of the Klamath Basin suckers testing the
waters of Upper Klamath Lake this summer in floating net
pens are thought to have died during a federally-funded
summer pilot project.
When U.S. Fish and Wildlife
Service visited the pens on the lake last week to
release them into the wild, 10 of the 1,000 endangered
fish were found alive, according to Evan Childress,
sucker recovery supervisor for U.S. Fish and Wildlife
Service. The fish that remained from the group were
plagued by open flesh wounds from Lamprey in addition to
Childress said the results stem
from working within the confines of “science in action”
with an endangered population. The sucker hasn’t made it
to adulthood in two decades and the agency is trying to
find out why, and what can be done to save them from
Childress admitted when asked that
he was disappointed in the outcome of the project but
that the team behind it is undeterred.
“The state of the Sucker
populations here is so dire that … we have to throw
stuff at the wall and see if it sticks,” Childress said.
“You have to try a lot of stuff and see which one hits
The $242,710-pilot project steered
by Childress and a group of biologists with
Congressional funding is leading them to identify a need
to release fish when they are bigger.
One parasite attacking the fish is
Lernea, a tiny, external crustacean parasite that sucks
the blood from the fish.
“They had them all up in their
nairs, which are essentially their nostrils,” Childress
“Each one would have 20 or 30 of
these parasites on them. A bunch of them had Lamprey
wounds ... The water quality also is a concern,” he
“You can see the Lamprey scars on
some of the adults,” Childress said. “But they’re able
to survive that. And you don’t see this kind of
infestation of Lernea.”
Lamprey are native to Upper
Klamath Lake and aren’t considered the only factor in
the matrix that leads to their survival or demise.
“They could be a piece of it,”
Childress said, of the Lamprey.
“We don’t know very much about it.
It was intriguing to see this many fish with the
injuries that we saw from the Lamprey. I definitely
would not draw the conclusion that this is what’s
Lamprey feed on Redband Trout in
addition to Klamath Basin Suckers.
“They’ve always been here so for
that to be the reason, something else would need to
change,” Childress said. “Their population would need to
be artificially high or the suckers would need to be
more vulnerable than they used to be, and we don’t have
any reason to expect that those things are occurring.”
Childress said he could see
evidence of some potential sick fish near the surface in
June, prior to Sen. Merkley’s visit in August.
“We went out mid-Summer when the
pH was very high, and we saw sick fish,” he said. “They
were not doing well, they were near the surface and not
“We’re going to adjust some things
and be a little bit more intensive about it,” he added.
Childress said it’s not clear how
to protect the fish from parasitic attacks, but
anticipates needed to install mesh that can keep
Lampreys from preying on the Sucker.
“We’re going to monitor it very
closely so that we can be sure to understand what’s
going on,” Childress said.
Only the big fish survive
U.S. Fish and Wildlife Service put
out 1-year-old and 2-year-old juvenile Sucker in the
floating net pens.
“No 1-year-olds survived,”
Childress said. “So, that says, let’s not release
1-year-olds. And the 2-year-olds that survived, only one
of them was smaller than average so the rest of them
were average or above average so … they were all
relatively large for their age.
“The biggest lesson, we’ve got to
get them big,” he added.
In 2020, Childress said the
federal agency will be able to release 3-year-old fish
for the first time.
“We’re hopeful that those are
going to survive at higher rates,” Childress said.
Childress said it’s common for
areas trying to raise sucker to survive in the wild to
increase the size of the fish. Such is true for those
propagating Razorback Sucker and June Sucker in Utah and
“Our initial target was 200
millimeters or about eight inches and all those programs
have increased their targets to 300 millimeters or 350
(millimeters),” he said. “They’ve basically found that
they’re not surviving when they release them at smaller
sizes. And so, we’re learning those same lessons here
and despite the potentially different reasons for not
making it, it seems that size is going to be important
kind of across the board.
USFWS looking for sucker recovery leader
Childress is leaving his post
after serving with U.S. Fish and Wildlife Service in
Klamath Falls for almost three years. He emphasized the
Sucker recovery team in place will keep the effort
U.S. Fish and Wildlife is
currently looking for a new lead to take charge of the
sucker recovery program.
“We’re not losing the
institutional knowledge with my departure,” Childress
“The staff is going to carry this
He said despite the loss of the
fish, there will still be an expansion of the
sucker-rearing ponds at the Gone Fishing facility,
located outside of Klamath Falls. Additional ponds are
hoped to finished in 2021, he said.
Sen. Merkley has previously
secured $3 million to expand the Gone Fishing
propagation facility, which he also toured this Summer
for the first time.
“I think that we’ve advanced the
sucker-rearing program significantly,” Childress said.
“We’ve probably quadrupled or more
capacity, and we’ve learned a lot about how to raise
these fish,” Childress added.
As far as the loss of Suckers in
Upper Klamath Lake, he’s optimistic that the federal
agency can try again in 2020 with older, bigger fish.
“This isn’t a waste, it’s an
opportunity to learn and do it better,” Childress said.
“It’s pretty clear from the results that larger fish did
“We need to be supplementing feed,
we need to be getting them as big as we possibly can to
make sure that they’re fat and happy out there in the