Fall chinook salmon are again returning to the Snake River in record numbers, for the third year in a row, a success that the Nez Perce Tribe attributes to the careful use of hatchery fish to supplement the wild population.
The Nez Perce recorded 9,345 gravel nests known as redds that returning adults built in the Snake River Basin between Lower Granite and Hells Canyon dams, the Columbia River Inter-Tribal Fish Commission (CRITFC) said on February 4.
“The continued success of the Snake River fall chinook returns over the past five 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, in a CRITFC statement on February 4. “This program highlights the success of salmon restoration programs and demonstrates our potential when we focus on rebuilding abundance.”
The Nez Perce Tribe is one of several entities collaborating to restore fall chinook salmon levels above the Lower Granite Dam, the CRITFC noted. Working with the Nez Perce 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.
To bring back something approximating historic levels of salmon, the Snake River fall chinook are supplemented with “biologically appropriate hatchery-reared fish” in a program that has been in operation since 1994, the CRITFC said. Each year the Nez Perce release 450,000 yearling fall chinook and 2.8 million sub-yearling fall chinook into the Snake and Clearwater rivers from their own tribal facilities, the CRITFC said, part of a larger program that sees up to five million fish released.
“Adult fall chinook salmon returns to Lower Granite Dam have increased from fewer than 1,000 adults to Lower Granite Dam annually from 1975-1995 to record counts of 56,565 adults in 2013 and 60,868 in 2014,” the CRITFC said in its statement. “These returns include record numbers of natural-origin fish returning to the spawning grounds, including 21,142 wild fish in 2013, 14,172 in 2014 and a preliminary estimate 16,212 in 2015. This equals approximately 28 percent of the 2015 return to the area.”
Such success has enabled the first fall chinook fishery on the Snake River in 35 years to open in 2009, the CRITFC said.
“The success of the Snake River fall chinook is something this region can really be proud of,” said CRITFC Executive Director Paul Lumley in the statement, alluding to a court win that netted Northwest tribes the right to supplement wild stocks with hatchery fish. “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.”