Record Number of Snake River Fall Chinook Spawn
Some 9,345 fall chinook salmon redds (gravel nests) have been counted in the Snake River and tributaries between Lower Granite and Hells Canyon dams.
The total is the highest number of redds counted since surveys began in 1988, according to a summary of the spawning surveys released this week, and is the result of the third highest adult Snake River fall chinook return -- 59,300 in all -- since the four lower Snake River dams were completed in 1975.
The previous high mark, set last year, was 6,715, about 30 percent fewer redds than in 2015.
In 1990, only 384 adult fall chinook were counted at Lower Granite Dam, located 107.5 miles upstream from the Snake's confluence with the Columbia. Snake River fall chinook salmon, as well as Snake River spring/summer chinook salmon, were listed in April 1992 under the federal Endangered Species Act as threatened.
Returns have increased to 56,565 adults in 2013 and 60,868 in 2014.
The returns include record numbers of natural-origin fish that are returning to spawn. That includes 21,142 natural-origin fish in 2013, 14,172 in 2014 and 16,212 in 2015 (a preliminary estimate from the Columbia River Inter-Tribal Fish Commission), or about 28 percent of the total return of adults to the area.
CRITFC gives credit for the record-returns of fall chinook to the Snake River Fall Chinook Program, which is a program of the Nez Perce Tribe, along with the program's co-managers, that supplement existing Snake River fall chinook salmon with "biologically appropriate hatchery-reared fish" to restore the runs upstream of Lower Granite Dam. The program was started in 1994 as a result of legal actions by the tribes under US v. Oregon, according to CRITFC.
Co-managers of the program are the Washington Department of Fish and Wildlife, Confederated Tribes of the Umatilla Indian Reservation, Idaho Department of Fish and Game, U.S. Fish and Wildlife Service, NOAA Fisheries and Oregon Department of Fish and Wildlife.
The hatchery supplementation program releases 450,000 yearling fall chinook and 2.8 million sub-yearling fall chinook every year from Nez Perce tribal facilities into the Snake and Clearwater rivers. Overall, the program releases 5 million juvenile salmon into the system.
"Many of the returning adult salmon spawn naturally and "are key to increasing natural-origin returns," CRITFC said.
"The continued success of the Snake River fall chinook returns over the past 5 years strengthens the argument for carefully managed hatcheries as a tool in salmon recovery," said Anthony Johnson, Chairman of the Nez Perce Tribal Executive Committee. "This program highlights the success of salmon restoration programs and demonstrates our potential when we focus on rebuilding abundance."
The increase in adult Snake River fall chinook returning to the river resulted in 2009 in the first fall chinook fishery in 35 years. It has continued annually.
"The success of the Snake River fall chinook is something this region can really be proud of," said Paul Lumley, Executive Director for the Columbia River Inter-Tribal Fish Commission. "Over the last 20 years, we've moved from the courtroom to supporting fisheries while putting a substantial number of retuning adults on the spawning grounds. This type of program should be replicated throughout the Columbia River Basin, not limited."
According to the spawning survey summary released by the Nez Perce Tribe, Idaho Power, U.S. Fish and Wildlife and the Washington Department of Fish and Wildlife (2015 Snake River Fall Chinook Salmon Spawning Summary), spawning began in mid-October, peaked in early November, declined the third week of November and was completed by early December.
The 2015 estimates include 3,155 (2,808 in 2014) redds in mainstem Snake River reaches upstream of Lower Granite Dam. Fall chinook passing over Lower Granite can spawn in the mainstem or veer off into tributaries. Lower Granite is the eighth and final hydro project the fish must pass on their spawning journey up the Columbia and Snake rivers. On the Snake, their journey is halted at Idaho Power's Hells Canyon Dam, an impassable facility about 140 river miles upstream of Lower Granite.
The 2015 estimates include 5,082 (3,118 in 2014) redds in the Clearwater River in 73 distinct locations. The Clearwater is a tributary that joins the Snake near the head of Lower Granite's reservoir at the Idaho-Washington border. The Clearwater flows out of central Idaho.
The lowest redd count for the Clearwater River Sub-basin since intensive surveys began was 4 redds in both 1990 and 1991, while the highest count was 5,082 redds in 2015.
Other estimates include 378 (342 in 2014) redds in the Grande Ronde River, 83 (103 in 2014) in the Imnaha River (Oregon), 142 (42 in 2014) in the Salmon River (Idaho) and 506 (302 in 2014) in the Tucannon River (Washington). The Grande Ronde originates in Oregon and flows across southeast Washington and into the Snake.
Since 2011, the mean number of redds counted in the Grande Ronde River Sub-basin has been 288, ranging from 154 to 378. The lowest redd count for the Grande Ronde Sub-basin since intensive surveys began was zero in 1989 and 1991, while the highest count was 378 in 2015.
Since 2011, the mean number of redds observed in the Imnaha River has been 67, ranging from 24 to 103. The lowest redd count for the river since intensive surveys began was zero redds in 1994 while the highest count was 132 in 2010.
Since 2011, the mean number of redds in the Tucannon was 408, ranging from 302 to 541. The lowest redd count for the river was 16 redds in 1987 and the highest estimate was 541 redds in 2012.
Since 2011, the mean number of redds occurring in the Salmon River has been 62, ranging between 31 and 142. The lowest redd count for the river since intensive surveys began was zero redds in both 1999 and 2000, while the highest count was 142 in 2015.
This was the 28th year of such surveys of the mainstem Snake River and most of the river's major tributaries, and the 23rd year for ground surveys in tributaries downstream of Lower Granite Dam.
In the past, surveys were by either manned airplane or helicopters, but in a nod to technology and safety, for the first time Idaho Power biologists completed the survey in the mainstem Snake River downstream of Hells Canyon Dam using just cameras mounted on unmanned drones.
"This is not the first time Idaho Power has used drones, but it is the first time we have used them exclusively," said Brad Bowlin, spokesperson for Idaho Power. "We have used them in conjunction with helicopters in previous years to establish baseline comparative data to ensure that the survey results we get with the drone match up with what is gathered using a helicopter."
Other agencies still use helicopters to complete their part of the survey, he added, although there has been strong interest in moving to drones in other areas as well.
Final results will be provided in annual reports to Bonneville Power Administration. Past reports can be found at www.bpa.gov.
The Snake River fall chinook recovery plan can be found at www.nmfs.noaa.gov/pr/hot_topics/2015/Nov/proposed_snake_river_fall_chinook_recovery_plan_october_2015.pdf
Year-End Salmon Tally: 2.3 Million Adult Salmon Cross Bonneville Dam, Nearly Half Fall Chinook by Staff, Columbia Basin Bulletin 12/4/15
2014 Snake River Fall Chinook Redd Count Estimate Highest Since Surveys Began In 1988 by Staff, Columbia Basin Bulletin 2/6/15
NOAA Fisheries Releases Draft Recovery Plan For Snake River Fall Chinook; $5.2 Million In New Costs by Staff, Columbia Basin Bulletin 11/6/15
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