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 Klamath Basin.

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 Klamath River.

“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 blooms.

“(But) a lot of research has indicated lake-level management is less critical to the survival of the fish than we previously thought.”

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
Lost 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, Buettner said.

“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 entrainment.

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 said.

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.”

Addressing problems

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, Buettner said.

“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 nutrients.

“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.