Broader approach needed for protection and recovery of fish in Klamath River basin
Instead of focusing primarily on how water levels and flows affect endangered and threatened fish in Oregon's Upper Klamath Lake and the Klamath River -- which runs from the lake and down through northern California before emptying into the Pacific -- federal agencies charged with protecting the fish should pay greater attention to other causes of harm, says a new report from the National Academies' National Research Council.
WASHINGTON, Oct. 24, 2003 -- Instead of focusing primarily on how water levels and flows affect endangered and threatened fish in Oregon's Upper Klamath Lake and the Klamath River -- which runs from the lake and down through northern California before emptying into the Pacific -- federal agencies charged with protecting the fish should pay greater attention to other causes of harm, says a new report from the National Academies' National Research Council.
While the committee that wrote the report endorsed proposals for a water storage bank and for special seasonal flow adjustments, it was skeptical of the value of increasing restrictions on the U.S. Bureau of Reclamation's Klamath Project, which delivers irrigation water to 220,000 acres of farm land.
The committee instead identified a strong need for other kinds of initiatives to protect the fish, such as removal of migration obstacles, improvement of habitat, and reduction of summer water temperatures in tributaries.
In 2001, both the U.S. Fish and Wildlife Service and the National Marine Fisheries Service issued "biological opinions" under the Endangered Species Act that required higher water levels to protect endangered suckers and higher flows to protect threatened coho salmon. In an interim report released last year, the Research Council committee found no substantial scientific support for the higher water-level or flow requirements, although it did find support for a number of other requirements. The committee also noted, however, that lower minimum water levels proposed by the Bureau of Reclamation lacked scientific backing as well.
In this final report from the committee, it reiterated that there is no evidence of a causal connection between water levels in Upper Klamath Lake and welfare of the lake's endangered suckers. Findings of the committee suggest that maintaining water levels higher than that of the recent past is not likely to be effective in restoring sucker populations. Similarly, the committee found that the effect of higher minimum flows in the Klamath River on coho salmon is unlikely to lead to their recovery, although higher flows may benefit other species that are not endangered or threatened.
The committee's report covers an array of problems, such as excessive growth of algae and depleted oxygen levels in Upper Klamath Lake, dams that block spawning migrations, competition from hatchery fish, excessive sediment in streams, loss of streambank vegetation, and high water temperatures in the summer. The report's main recommendation is that the federal agencies should broaden the scope of actions that address these issues, and that they should more directly encourage various stakeholders to take voluntary measures that benefit the fish.
"The continued emphasis on water levels in Upper Klamath Lake and the Klamath's main stem is too narrow a basis for the recovery of the suckers or salmon," said committee chair William M. Lewis Jr., professor and director, Center for Limnology, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder. "The agencies should develop expanded recovery plans that confront the root causes of the fishes' decline."
Within two years, the National Marine Fisheries Service should issue a recovery plan for coho salmon, and the U.S. Fish and Wildlife Service should issue one for suckers, the committee wrote. While developing the recovery plans, these agencies should consult not only with the Bureau of Reclamation, but also with other agencies such as the U.S. Forest Service. The two agencies should use their authority to modify forestry and road-construction activities on federal lands that are causing damage to fish habitat. The agencies also should take measures to prevent fish from getting trapped behind small dams on private and federal lands.
Recovery teams for suckers and salmon should be established to administer research and monitoring of the fish, added the committee, which noted that research and remediation have been hampered by a lack of central planning and insufficient external review. The report recommends that research and monitoring be guided by a master plan and be reviewed by a panel of outside experts every three years. In addition, the scientists who conduct the research should more frequently publish their key findings in peer-reviewed journals. To strengthen the connection between research and remediation, the recovery teams should adopt the principles of adaptive management, which allow for the testing and refinement of remediation strategies.
Because suckers are not showing signs of recovery, new steps to promote their resurgence are needed as soon as possible, the report says. It recommends the removal of the Sprague River's approximately 12-foot-high Chiloquin Dam, which blocks as much as 90 percent of the spawning habitat for suckers above Upper Klamath Lake. In fact, any small dam or other diversion that blocks suckers from nearby tributaries where they would normally spawn should be either removed or remodeled to facilitate the passage of fish. Larger dams need screens to prevent suckers from getting caught in turbines or from traveling to water bodies from which they cannot return.
Mass fish kills affecting suckers in Upper Klamath Lake have occurred for many decades but they have increased in frequency and severity since the rise of a kind of algae called Aphanizomenon. These algae thrive on the lake's high concentrations of phosphorus, which comes from both natural and human sources. Death of Aphanizomenon leads to lower than normal concentrations of oxygen, which is probably the immediate cause of fish kills. The committee wrote that adding oxygen to parts of the lake should be pursued on a trial basis. Because the abundance of algae likely cannot be reduced in the near future, the committee called for the establishment of new populations of endangered suckers at locations other than Upper Klamath Lake.
The biggest detriment to coho salmon is probably excessively high summer temperatures in tributary waters, the committee concluded. To remedy this problem, cool water should be procured -- by purchasing, leasing, or trading for groundwater -- to re-establish lower summer temperatures in streams, and woody vegetation should be restored along the tributaries to provide shade. Agriculture, forestry, and road construction should be managed to prevent further degradation of tributary habitat in the lower basin, and officials should consider removing the Dwinnell and Iron Gate dams, which block access of coho salmon to good habitat.
Competition with fish grown in hatcheries and released into the river could be a severe handicap to the recovery of coho salmon, the committee noted, adding that hatcheries may need to close or alter their operations if adaptive management of hatcheries verifies that current operations are harmful to coho.
About 30,000 migrating adult salmon were killed in the Klamath River last year by two common pathogens that become lethal to fish under stress. Most of the salmon killed were chinook, which are not listed as endangered or threatened. Only about 1 percent were coho, which migrate later than chinook. Studies by the California Department of Fish and Game and the U.S. Geological Survey showed that neither the river flows nor temperatures that occurred during the fish kill were unprecedented, and the committee agreed that neither flow nor temperature conditions alone can explain the fish kill.
The committee estimated that the research, monitoring, and remediation outlined in its report would cost about $25 million to $35 million over the next five years, excluding costs for major projects such as dam removal.
The report was sponsored by the U.S. Bureau of Reclamation and U.S. Fish and Wildlife Service at the U.S. Department of the Interior, and the National Marine Fisheries Service at the U.S. Department of Commerce. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides advice to the federal government on science and technology under a congressional charter. A committee roster follows.
Copies of Endangered and Threatened Fishes in the Klamath River Basin: Causes of Decline and Strategies for Recovery will be available early next year from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at http://www.nap.edu. Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).
For more information, visit http://national-academies.org.