Saving three species of endangered fish along the Oregon-California border will take more than just regulating irrigation water, according to a report released yesterday by the National Research Council (NRC). Among the fixes, the report recommends considering tearing out dozens of small dams, temporarily closing a fish hatchery, restoring wetlands, altering logging practices, and refilling long-drained lakes. Critics say such wide-ranging actions--though commendable--might not come in time to save fish stocks already in peril.
Many scientists think that the best way to help the fish is by getting more water into the Klamath River. That means turning down the spigot for farmers who irrigate crops with water from Upper Klamath Lake. Last year, however, the NRC committee released an interim report that drew widespread fire from researchers and environmentalists; it concluded that there was no scientific evidence that endangered salmon or threatened suckers would benefit (Science, 4 April, p. 36). In the final report, the committee stuck by their previous assessment. "Further negotiation over water levels will not lead to meaningful recovery of the fish," says William Lewis Jr., a limnologist at the University of Colorado, Boulder, who chaired the 12-member committee.
Instead, Lewis and other committee members say that the focus of recovery efforts must be on improving habitat for spawning and rearing. Also needed is monitoring to help fisheries managers select the actions that work best. "The endangered sucker and coho are a symptom rather than a disease," says Peter Moyle, a committee member and fisheries biologist at the University of California, Davis. "The only way to solve these problems is to look at collective problems in the basin," he says.
The committee estimates that it will cost up to $35 million to set up a broad-based research program throughout the basin and carry out habitat improvements such as installing screens at the headgates of irrigation canals to prevent fish from being swept inside. Major changes, such as tearing down dams, will likely cost much more. Says Douglas Markle, a fisheries biologist at Oregon State University in Corvallis: "Making any of that happen is the rub in all of this."
Announcement from the National Academy of Sciences