In response to ongoing fish monitoring data from federal and tribal biologists, Klamath Water Users Association (KWUA) is sounding the alarm and calling for urgent action to avoid the complete loss of two fish species in Upper Klamath Lake. C’waam and Koptu, in the Klamath Tribes traditional language, also known as shortnose and Lost River suckers, appear to be on the brink of extirpation from Upper Klamath Lake.
Since 1991, the U.S. Fish and Wildlife Service has relied on managing water levels in Upper Klamath Lake (and reducing agricultural water supplies accordingly) as the primary means to try to protect these species. Lake levels have also been managed as a purported means of improving water quality.
Those strategies have proven to be failures. Over thirty years of empirical data evidence and research have shown that lake-level management does not improve water quality or help the species. “Regulating water levels and fighting about water levels are distractions that have not helped these fish,” said KWUA President Tracey Liskey.
Federal scientists have monitored the populations for more than two decades, using microchip devices to track the movements of individual adult fish. These extremely hardy fish, which can live longer than thirty years, have been regularly found spawning year after year in the Williamson River and its tributaries and at shoreline sites around the lake.
Monitoring from 2024 shows a marked decrease in adult fish being detected at all locations.
For example, from 2011 to 2016, thousands of adult Lost Rivers suckers (Koptu) were detected each year at shoreline spawning sites in Upper Klamath Lake. The figure has dropped steadily. This year, fewer than a thousand fish showed up.
Larger numbers of both species spawn in the Williamson River, yet similar apparent declines have been observed in those populations this year. In 2016 and prior, the annual figure was over 20,000 adult fish. This year, it was less than a quarter of that figure.
Over recent years, it has become broadly understood that the population bottleneck is the lack of recruitment of larval fish to adulthood, meaning that the number of fish that can reproduce is dropping, and adults are aging and dying.
“All data overwhelmingly point to the conclusion that only two age-classes of fish, one from the early 1990s and the other from the late 1960s, have led to significant recruitment of fish into the adult population,” according to Moss Driscoll, KWUA’s Director of Water Policy. “Whether we see high lake levels or low lake levels, poor water quality or good water quality, the hundreds of millions of larvae hatched each year just don’t survive to adulthood. This year is no different.”
In recent years, agencies have tried to stabilize the population through a program that captures larval fish and grows them in tanks and ponds before release into Upper Klamath Lake. Efforts have been unsuccessful so far. These fish are rarely found in the lake despite tens of thousands having been released annually since 2020.
“We still believe captive rearing can be an effective tool to keep the populations going,” said Driscoll. “But the strategy needs to evolve, to growing the fish larger, or releasing them in other locations, or both.”
Notably, these species are doing well in waters other than Upper Klamath Lake. Healthy Lost River and shortnose suckers are regularly found in other areas, waterbodies served by Klamath Project infrastructure, and even canals and drains within the Klamath Project. For example, for the last two years, farmers in the Tule Lake basin have been raising suckers in a so-called “walking wetland,” which previously was a field of organic potatoes.
Both species are also found in healthy numbers and succeeding in Clear Lake Reservoir, which has no emergent wetland vegetation, routinely experiences extremely low water levels, and has naturally compromised water quality (turbidity or suspended sediment). KWUA and others have pointed out that Clear Lake does not have populations of certain nonnative predators that are abundant in Upper Klamath Lake, particularly yellow perch. This issue has received little focused attention from researchers.
The 2024 data is still preliminary; federal agencies will make the final figures public later. Yet the potential implications are grave enough to require immediate action. “Farmers believe in solving problems,” said Liskey. He and one of his neighbors used their own equipment to help the U.S. Fish and Wildlife Service start the sucker-rearing program, which has expanded to cover several acres of ground down the road from his house. “We need to do what works.”
Cover Photo: A pair of adult Lost River suckers during the spring spawning season in Upper Klamath Lake. These endangered fish and the shortnose sucker, most over 30 years old, spawn primarily in tributaries of the lake, and produce large numbers of eggs and larvae. Unfortunately, most of their offspring will not survive beyond their first year of life in the lake. (Photo By/Credit Jason Ching/USGS)
