You’d never suspect it on a whisper-still morning, with the mountains and marsh reflecting off the water, but Upper Klamath Lake is a tough place to be a fish.
The shortnose and Lost River suckers provide a case in point. The two species of fish, which look like a big-lipped cross between a carp and cod, used to be common in this southern Oregon lake. For millennia, they were an important traditional food source for the local tribes. The federal government considers them endangered species.
There’s a population of long-lived adult suckers hanging on and continuing to reproduce, but virtually none of their offspring are surviving for longer than a year.
“The juvenile sucker, they’re dying off. They’re not recruiting new adults,” said Mason Terry, a renewable energy professor at the Oregon Institute of Technology in Klamath Falls.
Water quality in Upper Klamath Lake is considered a significant cause of the sucker death. One of the lake’s most significant water quality problems is a low dissolved oxygen issue called hypoxia.
Fish breathe oxygen out of the water, and the oxygen levels here can drop extremely low, especially in late summer. That coincides with the time juvenile suckers appear to just vanish from the lake.
When Terry learned that low oxygen levels were one of the suspected reasons the endangered suckers aren’t surviving into adulthood, he had an idea.
“I thought, Why don’t we do what they do in fish ponds or in your aquarium? Why don’t we just try and bubble some air down in there and see what happens?” he said. “See if there’s just a little boost to affect this one factor that might be a cause of their mortality.”
Sucker BubblerTerry’s renewable energy students at OIT dragged a floating solar panel raft — about as large as a single-car garage — out of the lake and onto the Rocky Point boat landing on the northwest side of the large, shallow lake.
This was the final assembly site for a solar-powered aeration system designed by Terry.
“Let’s just grab the next battery and bring it up here since it’s going to be the most annoying thing to do,” Ian Riley said to his classmate Mohammed Bawazeer.
They walked it over to a plastic dry box that would protect all the electrical components of the system from the elements.
Four 310-watt panels would run two compressors that push air — with all the oxygen it contains — down into the lake. Any power left over would go to charge the batteries, which are designed to power the compressors for 32 hours without sun.
As work on the raft wrapped up, Jennifer Berdyugin, who helped coordinate the project, inspected the work to make sure all the components were hooked up.
“All that’s left to do is turn on the pump and then make sure that it’s bubbling the water. So, really, the telltale will be, ‘Are there bubbles or not?’” she said.
The renewable energy students dragged the solar raft back into the lake. With the push of a button the compressor came to life.
The air hose turned into an underwater sparkler as air was pushed through thousands of tiny holes.
“Bubble, bubble!” Riley called across the noise as another student clapped in celebration.
The team assembled two rafts that are currently anchored at a site on the lake where juvenile suckers have been found to gather.
“It’s a way to provide an area for the suckers to get out of the bad water quality and at least have somewhere to hide until things get better,” said U.S. Fish and Wildlife biologist Josh Rasmussen, who works on sucker conservation in the Klamath Basin.
Aerated FutureUpper Klamath Lake isn’t alone in having water quality issues related to low dissolved oxygen. The chemistry of lakes worldwide has been altered by human development and agriculture — Upper Klamath included.
Ken Ashley, a lake aeration specialist at the British Columbia Institute of Technology, said the problems are only going to get worse with climate change.
“As the climate gets warmer and lakes are stratified longer, then the effects of the low oxygen are going to get magnified and there’s going to be more algal problems, and more fish kills, and more taste and odor problems. And there’ll be more demand to do something about it,” Ashley said.
When the temperature of water on the surface rises, it prevents oxygen from getting to lake bottoms. Aeration can be a solution.
“It’s a growth industry, unfortunately,” he said.
Whether aeration is the solution for Upper Klamath Lake suckers won’t be apparent immediately.
One challenge is that Upper Klamath Lake is really big — the largest in Oregon. A pinpoint or two of aeration floating in a hundred-square-mile lake won’t be the ultimate answer. But it could help conditions immediately around the rafts.
“I think it’s an elegant solution,” OIT’s Terry said.
With the two rafts now operating in the lake, the Klamath Tribes are engaged in monitoring the systems. Terry said preliminary measures show oxygen levels in the vicinity of the rafts have improved.
“We need to explore any remedy we can to help the fish with low oxygen and water quality,” Klamath Tribes Chairman Don Gentry said.
Terry will use the information the tribes collect to tweak and launch two more solar aeration systems next year.
But success of the systems won’t ultimately be known until the next fish counts reveal whether any Upper Klamath Lake suckers survive past their first birthday.