The Most Endangered Salmon Runs in the Columbia Basin

By PAUL KOBERSTEIN

Salmon populations in the Columbia Basin are constantly changing. In some years, numbers increase, giving hope that recovery is on the way. Then they reverse direction. Hydrosystem operations in the basin affect trends, as do changes in rainfall and ocean conditions. 

In the late 1990s, good river and ocean conditions sparked an increase in the salmon runs. A severe drought in 2001, however, led to declines in the last three years. The number of salmon crossing Bonneville has declined 50 percent since 2001, and forecasts for 2007 signal another down year.

Recent assessments on the long term trends for ESA-listed species, including Snake River steelhead, spring chinook, and fall Chinook, and Upper Columbia River Chinook and steelhead are discouraging. Although some of these populations have seen short-term increases in adult returns, “all are still experiencing a long-term population decline and remain at significant risk, especially in terms of abundance (number of adults) and productivity,” said Gretchen Oosterhout, a noted salmon statistician.

Although these are the only Columbia River salmon listed under the Endangered Species Act, they are not the only salmon harmed by dams. The Hanford Reach fall Chinook, the last major wild run in the basin, have been dying by the million as a result of operations at Grand Coulee and Priest Rapids dams. And Pacific lamphrey, an important food fish for tribal members, have been decimated by hydropower.

1. Snake River sockeye
Historic population: between 45-55,000 around 1900.
2006 population: Only 3
Wild component: Only 16 total since 1991.
Listed: Endangered in 1991.
Notes: During the early 1880s, Snake River Sockeye Salmon returns to Wallowa Lake, Oregon, were estimated at between 24,000 and 30,000 per year.

2. Snake River fall Chinook
Historic population: About 450,000 around 1900.
2005 population: Fewer than 5,000.
Wild component: 40 %.
Listed: Threatened in 1992.
Notes: Estimated returns of naturally-produced adults from 1985 through 1993 ranged from 114 to 732 fish. About 80 percent of its historical spawning habitat was lost with the construction of a series of dams on the mainstem Snake River. Currently, natural spawning is limited to the area from the upper end of Lower Granite Reservoir to Hells Canyon Dam, and the lower reaches of the Imnaha, Grande Ronde, Clearwater and Tucannon rivers.

3. Snake River spring/summer Chinook
Historic population: About 2 million around 1900.
2005 population: About 30,000.
Wild component: 20 %.
Listed: Threatened in 1992.
Notes: Abundance of adults declined to about 125,000 per year during 1950-1960.

4. Snake River steelhead
Historic population: About 325,000 in 1900.
2005 population: About 150,000.
Wild component: 15 %
Listed: Threatened in 2005.
Notes: There are six major populations in this species: the Clearwater River, the Grande Ronde River, Hells Canyon, the Imnaha River, Lower Snake River and the Salmon River. Of major concern is the large number of hatchery fish that are widespread and stray to spawn naturally throughout the region.

5. Upper Columbia River spring Chinook
Historic population: About 30,000 in 1900.
2005 population: Close to 2,000.
Wild component: About 100 fish.
Listed: Endangered in 1999.
Notes: At least six former populations from this species are now extinct. Other than Snake River sockeye, which are very close to extinction, this is the most endangered stock in the basin.

6. Upper Columbia River steelhead
Historic population: About 20,000 in 1900.
2005 population: About 18,000.
Wild component: 9 to 35 %
Listed: Endangered in 1997; changed to Threatened in 2005.
Notes: The major concern for this species was the clear failure of natural stocks to replace themselves.

7. Middle Columbia River steelhead
Historic population: About 100,000 in 1900.
2005 population: About 20,000.
Wild component: 70 %
Listed: Threatened in 1999.
Notes: The Middle Columbia River Steelhead occupy the Columbia River Basin from above the Wind River in Washington and the Hood River in Oregon and continue upstream to include the Yakima River in Washington. Within this area are 15 populations in four major population groups: Cascades Eastern Slope Tributaries, John Day River, Walla Walla River, and Umatilla River. Populations in the White Salmon River and the Deschutes River above Pelton Dam are extinct.

8. Lower Columbia River chinook
Historic population: About 500,000 around 1900.
2005 population: About 60,000.
Wild component: 50 %.
Listed: Threatened in 1999.
Notes: Cannery records suggest a peak run of 4.6 million fish in 1883. The species includes all native populations from the mouth of the Columbia River to the crest of the Cascade Range, excluding populations above Willamette Falls. Natural production occurs in approximately 20 populations, although as of 2001 only one population had a mean spawner abundance exceeding 1,000 fish.

9. Lower Columbia River steelhead
Historic population: About 250,000 million around 1900.
2005 population: About 16,000.
Wild component: 70 %.
Listed: Threatened in 1998.
Notes: The Lower Columbia River Steelhead encompasses all runs in tributaries between the Cowlitz and Wind Rivers on the Washington side of the Columbia River, and the Willamette and Hood Rivers on the Oregon side.

10. Lower Columbia River coho
Historic population: About 1 million around 1900.
2005 population: Fewer than 200,000.
Wild component: 10 %.
Listed: Threatened in 2005.
Notes: There are only two remaining populations, in the Clackamas and Sandy rivers populations, down from an estimated 23 historical populations in the species. About 40 percent of its original habitat is inaccessible.

11. Lower Columbia River chum
Historic population: About 1.4 million around 1900.
2005 population: About 12,000.
Wild component: 90 %.
Listed: Threatened in 1999.
Notes: Chum salmon in the Columbia River spawn in tributaries and areas below the Bonneville Dam. Most runs disappeared by the 1950s.

12. Upper Willamette River chinook
Historic population: About 300,000 in 1900.
2005 population: About 50,000.
Wild component: 20 %
Listed: Threatened in 2005.
Notes: The Upper Willamette River Chinook species includes native spring-run populations above Willamette Falls and in the Clackamas River. Of the historical populations, 8 to 10 have been extirpated or nearly extirpated. Natural production currently occurs in approximately 20 populations, although only one population has a mean spawner abundance exceeding 1,000 fish.

13. Upper Willamette River steelhead
Historic population: About 200,000 in 1900.
2005 population: About 5,000.
Wild component: 75 %
Listed: Threatened in 1999.
Notes: The Upper Willamette River Steelhead species occupies the Willamette River and tributaries upstream of Willamette Falls, extending to and including the Calapooia River. Native winter steelhead within this species have been declining since 1971 and have exhibited large fluctuations in abundance.

Paul Koberstein