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WDFW Survey Shows Spring Chinook Spawning Higher Up In White Salmon River Above Old Condit Dam Site
Posted on Friday, February 03, 2017 (PST)

Spring chinook salmon are continuing to spawn in the newly-created habitat upstream of where Condit Dam once blocked their access on the White Salmon River, while mostly spring and fall chinook and steelhead are spawning in the 3.3 miles of river below the old dam site.

 

At 125 feet high, the PacifiCorp dam was one of the largest dams to be removed in the Pacific Northwest, creating 33 miles of new habitat for salmon and steelhead that had been extirpated from the river when the dam was built in 1913. The dam was breached October 26, 2011.

 

It’s the spring chinook salmon that are taking hold in the new habitat and this year biologists found spawning fish even farther up the river than they have seen them since surveys above the old dam site began.

 

“One of the really interesting things we saw this fall that we haven’t seen in previous years is spring chinook spawning above Husum Falls,” said fisheries biologist Jeremy Wilson, author of the January 25, 2017, Washington Department of Fish and Wildlife memorandum on the white salmon chinook survey. “The past couple of years we saw quite a few spring chinook redds and spawners in the reaches directly below Husum Falls, but nothing between BZ Falls and Husum Falls.”

 

That, he said, suggests that Husum Falls had been a barrier to spring chinook.

 

“That changed this year as we had spring chinook redds between BZ Falls and Husum with little spawning activity directly below Husum Falls.”

 

WDFW conducted weekly spawning surveys from early August 2016 until completion of spawning in late-November. The surveys were taken from BZ Falls at river mile 12.34 to the river’s confluence with the Columbia River upstream of Bonneville Dam.

 

The actual numbers are still small. Throughout the 12.34 miles of river where spawning occurs, just 54 are spring chinook. Tule fall chinook spawners, however, totaled 648 and bright stock fall chinook tallied in at 2,743 spawners.

 

All the spawners upstream of the old dam site were spring chinook in 2016. In fact, 40 percent of all the spring chinook that spawn in the river do so upstream of the old dam site, while no tule fall chinook or bright stock fall chinook spawned in the area.

 

The 2015 spawning survey found that 94.3 percent of spring chinook spawned upstream and just 0.1 percent of fall chinook spawned in that stretch of river.

 

Some 35.5 percent of spring chinook spawned upstream of the old dam site in 2014, while 0.5 percent of fall chinook spawned upstream.

 

The remaining fish spawn in the 3.3 mile stretch of river downstream of the old dam site.

 

Of the spawning salmon, 31.3 percent of the tule fall chinook are of hatchery origin, the lowest percentage of the three chinook stocks present in the river. Some 70.5 percent of the fall chinook bright stock and 88.2 percent of the spring chinook have hatchery origins.

 

Prior to Condit Dam’s removal Columbia River tule fall chinook was the only salmonid spawning in any numbers in the river. The fish is one of 13 salmonid stocks listed under the federal Endangered Species Act in the Columbia River basin. It is listed as threatened.

 

Fall chinook, both tules and brights, are still concentrated below Steelhead Falls in the lower White Salmon (which is below the old Condit site), according to Wilson.

 

“This is what you would expect,” he said. “Spring chinook, steelhead, and coho should be the anadromous fish that really benefit from the newly opened up habitat in the upper watershed.”

 

WDFW’s work is focused on adult chinook monitoring, Wilson said. The Yakima Nation does the adult steelhead monitoring and at this point there is no directed coho monitoring in the White Salmon River.

 

A November 4, 2015 USGS study (“Effects of Dam Removal on Tule Fall Chinook Salmon Habitat in the White Salmon River, Washington,” http://onlinelibrary.wiley.com/doi/10.1002/rra.2982/abstract) said that dam breaching “dramatically affected channel morphology and spawning habitat due to a large load of sediment released from Northwestern Lake,” the lake formed by Condit Dam for nearly 100 years. “Forty-two per cent of the project area that was previously covered in water was converted into islands or new shoreline, while a large pool near the mouth filled with sediments and a delta formed at the mouth.”

 

The pool area that was Northwestern Lake decreased 68.7 percent, but glides and riffles – features most conducive to spawning – increased 659 percent and 530 percent, respectively, the report says. Spawning habitat increased by 46.2 percent after dam breaching due to an increase in glides and riffles.

 

Also see:

 

--CBB, December 11, 2015, “USGS Studies Document Changes in White Salmon River Post-Condit Dam; More Salmon, Steelhead Spawners,” http://www.cbbulletin.com/435674.aspx

 

--CBB, February 13, 2015, “Salmon, Steelhead Spawning, Rearing In New White Salmon River Habitat Above Removed Condit Dam Site,” http://www.cbbulletin.com/433156.aspx

 

-- CBB, May 31, 2013, “A Year After Condit Dam Breaching, Natural Origin Salmonids Spawn In New Miles Of Upstream Habitat” http://www.cbbulletin.com/426822.aspx

 

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