Continued improvements to dam operations and fish habitat are needed to restore populations of spring and summer chinook salmon and steelhead on the Snake River, according to a proposed recovery plan released Thursday.
The National Marine Fisheries Service recovery plan would require an estimated 50 to 100 years to restore populations spawning in the wild to levels needed to remove the species from federal protections under the Endangered Species Act.
“The decline of these species took a long time. It continued over many decades and it is going to take a similar amount of time, perhaps, to recover them,” said spokesman Michael Milstein.
Some of the proposed improvements, such as better water quality and restoring flood plain areas to allow natural ecosystem processes to improve, can take years to show full benefits.
Snake River spring and summer Chinook once represented close to half of all salmon and steelhead returning to the Columbia River system. But chinook were listed as threatened under the Endangered Species Act in 1992 and steelhead were listed as threatened in 1997.
Both species are considered at risk of becoming endangered within the foreseeable future throughout all or a significant portion of their range, said Rosemary Furfey, a recovery coordinator for the fisheries service.
The proposed plan builds on earlier efforts to increase populations of threatened species, confirming they were correct, and building momentum for the future, said Steve Martin, executive director of the Snake River Salmon Recovery Board in Dayton.
Mid-Columbians who use the Lower Snake River for fishing or irrigation, or rely on the hydropower it produces, may not notice changes, according to fisheries service officials.
The extremely low rate of migration survival of juveniles recorded before 2000 has been replaced with a survival rate of 40 to 65 percent for juveniles from Lower Granite Dam on the Snake River to Bonneville Dam on the Columbia River, said Ritchie Graves of the fisheries service.
The proposed plan, required for threatened species by the Endangered Species Act, is a roadmap that draws on the latest information and science to continue actions that will make the biggest difference for fish over the long term, Furfey said.
It also recognizes that more research is needed to better understand chinook and steelhead survival. The reason for losses of young fish in tributaries of the Snake River is not clear, for example. The survival patterns of fish when they exit the Columbia River into the Pacific Ocean — an ecosystem called the plume — also is not clear.
The plan covers action in three states — southeast Washington, northwest Oregon and Idaho — as some fish begin life up to 900 miles inland and then travel through eight major hydroelectric dams to the Pacific Ocean.
Goals are specific to different areas. The Tucannon River, for example, would require a population of 750 spawning spring and summer chinook and 1,000 spawning steelhead as part of the goal to de-list the species.
Actions proposed in the plan would be voluntary. The fisheries service relies on federal, state, tribal and local agencies and organizations to implement actions. It was developed in coordination with — and in some cases by — state, tribal and federal programs.
Potential actions for the Army Corps of Engineers at its Snake and Columbia River dams include continuing to cool water for summer chinook and steelhead.
The recovery plan takes into account a much larger legal battle involving all 13 endangered and threatened salmon and steelhead runs in the Columbia Basin.
In May, a federal judge in Portland, Oregon, ruled that the massive habitat restoration effort by the U.S. government doesn’t do nearly enough to improve Northwest salmon runs, handing a major victory to conservationists, anglers and others who hope to someday see the four dams on the Snake River breached to make way for the fish.
The judge ordered the government to come up with a new plan by March 2018.
The recovery plan released Thursday doesn’t include removing the Snake River dams, but has language that would allow it to be modified to bring it in line with whatever comes out in the court-ordered 2018 plan.
More information is posted at bit.ly/2eARWF5. Public comment may be submitted through Dec. 25 to email@example.com or to Rosemary Furfey, NOAA Fisheries West Coast Region, 1201 N.E. Lloyd Boulevard, Suite 1100, Portland, OR 97232.
A final plan will be released after public comments are considered, possibly in mid-2017.
The Associated Press contributed to this story.