Scientists cautiously optimistic about recovery
Shortnose sucker illustration by Joseph Tomelleri/U.S. Fish and
By Jill Aho, Herald and News 9/13/09.
Maybe how much water
is in Upper Klamath Lake isn’t the most critical element to the
survival of the endangered Lost River and shortnose suckers. Maybe
the rivers and wetlands that feed the lake, not the lake itself,
dictate whether the fish survive.
That’s what researchers have learned since the sucker was listed
21 years ago as an endangered species, said U.S. Fish and Wildlife
fish biologist Mark Buettner.
At the time, little was known about the habitats, needs and
populations of Lost River and shortnose suckers. What was known
was the fish were in rapid decline, and no significant additions
to the population in Upper Klamath Lake had been seen in 18 years.
That decline — and the resulting federal listing — put the sucker
at the heart of an ongoing struggle for water rights in the
The sucker — culturally and historically significant to the
Klamath Tribes — was often blamed for the 2001 water shutoff to
irrigators in the Klamath Reclamation Project. Federal officials
maintained they had to cut irrigation to maintain water levels in
Upper Klamath Lake for the endangered fish. Federal officials
maintained they had to cut irrigation to maintain water levels in
Upper Klamath Lake for the endangered fish.
That shutoff spurred what is now known as the Klamath Basin
Restoration Agreement, a proposal that aims to settle water
disputes throughout the Klamath River watershed.
The removal of four hydroelectric dams along the river to restore
salmon runs is key to the agreement and is being negotiated by the
dam owners PacifiCorp and other stakeholders.
But recovery of the sucker and delisting the fish from the
Endangered Species List is one way to help ensure stable water
supplies for farmers, some say.
The U.S. Fish and Wildlife Service, along with a team of
scientists and other stakeholders, is drafting a plan to do so.
The sucker recovery plan should be ready for review by scientists
from outside the Klamath Basin in October, Buettner said. The team
will provide input on whether actions may harm stakeholders and
are reasonable, Buettner said.
Learning about the fish
While the plan is being developed, more is becoming known about
the suckers. Biologists found sucker populations in Lost River,
Clear Lake, Gerber Reservoir, Tule Lake and reservoirs through the
“Another key research finding was the management of Klamath Lake,”
Buettner said. “Basically, it was felt that you had to have
certain high lake levels in order to protect the habitat for
spawning and shoreline vegetation for young suckers, and you
didn’t want that lake to get too low or it would affect algae
“(But) a lot of research has indicated lake-level management is
less critical to the survival of the fish than we previously
Beginning in 1992, Upper Klamath Lake was kept at a minimum
elevation of 4,139 feet. A Fish and Wildlife Service biological
opinion issued in 2001 raised the minimum to 4,140 feet with no
exceptions for droughts, according to the Bureau of Reclamation.
In 2001, there was a drought, forcing the BOR to cut off the
irrigation deliveries to farmers in the Klamath Project.
“In 2001, we had very strict lake level requirements,” Buettner
said. “We thought lake level management affected algae blooms.”
Lake level management was modified based on a 2008 biological
opinion from the U.S. Fish and Wildlife Service that allows the
lake to drop to a minimum of 4,137.5 feet in September, the end of
the irrigation season.
Surviving to adulthood
River suckers can live 43 years. The survival of young fish in
Upper Klamath Lake is a concern.
Research also indicates that larval and juvenile suckers are
dependent on the presence of wetland vegetation for survival,
“As a result of that, restoration of the Williamson River Delta
was recently completed, and we’re expecting some pretty major
benefits from that restoration and improved survival of young
suckers,” he said.
There is a gap in ages of suckers in the lake, and no significant
populations of young fish have been added. Young suckers were
suspected to be leaving the lake through the A Canal, and in 2002,
the Bureau of Reclamation installed a fish screen to address
The screen is working, according to Bureau of Reclamation
spokesman Kevin Moore.
But young suckers still are not surviving in large enough numbers
in Upper Klamath Lake to indicate the fish is recovering, Buettner
Suckers are long-lived. The Lost River sucker lives as long as 43
years and reaches sexual maturity at about nine years. The
shortnose sucker lives as long as 33 years and reaches sexual
maturity at six or seven years.
H&N photo by Jill Aho - Missy Braham, a fish technician with the
Bureau of Reclamation, prepares to measure a young sucker caught
by a fish screen on the A Canal. Once a week, fish biologists
visit the evaluation station to see what kinds of fish are being
diverted from the canal and sent back to Upper Klamath Lake.
Although the fish lay thousands of eggs and many get fertilized,
the young are eaten by native and non-native fish and are
particularly susceptible to poor water quality conditions in the
lake, biologists say.
“We’re cautiously optimistic that a lot of the projects that have
taken place in that area will result in improved survival,”
Buettner said. “We still have thousands of Lost River and
shortnose suckers, but they’re primarily adults. For recovery, we
would want to see a more diverse age class structure.”
Major die-offs of suckers in Upper Klamath Lake have diminished
the available adult breeding population by 80 to 90 percent,
Buettner said. Warm temperatures and high concentrations of
blue-green algae, which reduce the amount of dissolved oxygen in
the water, create stressful conditions for the fish, he said.
No major fish die-offs have been observed since 1997, but that
doesn’t mean the fish survived.
Brian Hayes, a U.S. Geological Survey fish biologist, shows a
large female Lost River sucker from Upper Klamath Lake
“Some of our adult survival information shows that even though we
don’t see a bunch of dead fish, there have been years when adult
survival hasn’t been as high as we thought it would be,” Buettner
said. “The lake is so big, so turbid, you may not see the fish.”
Upper Klamath Lake’s algae blooms occur every year. It is believed
that nutrients from downstream, exacerbated by land use practices
in the late 1800s and early 1900s, are contributing to the blooms,
“Most of those are legacy effects. They happened a long, long time
ago,” he said. “(The lake) used to be more diverse in the types of
algae, and in the last 100 years, it’s been a monoculture of this
blue green algae. It just flourishes.”
Restoration of wetland areas near Upper Klamath Lake may help to
address the sediment problems that contribute to algae blooms.
Wetlands are thought to act as a sponge that filters out
“A lot of the nutrient issues have been improved, but one of the
challenges is Klamath Lake is shallow, and there’s a lot of these
nutrients that have accumulated in the shallow bottom. It takes
time for those nutrients to decrease,” Buettner said.
“It may have taken a century to get to the current status, and
it’s going to take a long period of time to make major
improvements in water quality of the lake.”
In the meantime, it is important to make sure the fish have refuge
in areas like Pelican Bay, Wood River and the Williamson River
Delta, biologists say. The areas are cooler and have more oxygen
than the open lake.