A report from Idaho’s Snake River region confirms that runs of fall chinook have made a resurgence in recent years – a credit in large part to the work of hatcheries in the US Pacific Northwest.
Chinook were driven almost to extinction by the building of Idaho Power’s Hells Canyon dams during the 1950s and ’60s, which shut off access to more than 80% of the streams that had been chinook spawning grounds.
The comeback has been credited to the hatcheries and rehabilitation work of Idaho Power, the Nez Perce tribe, state and federal officials. The Bonneville Power Administration says that last year saw more than 75,800 wild and hatchery-born fall chinook return to Lower Granite Dam on the Snake.
The turnaround began in the 1980s when the Lyons Ferry hatchery was built in Washington state and native Snake River fish were captured to provide broodstock. Idaho Power put up the money for the release of a million smolts into the Snake at Hells Canyon.
In 2003, with funding from the Bonneville Power Authority, the Nez Perce tribe completed a modern hatchery on the Clearwater, which sent the number of Snake River fall chinook smolts produced in hatcheries to 5.5 million, the current figure.
— Quentin Dodd
The three dams of the Hells Canyon Project blocked access by chinook salmon to a stretch of the Snake River drainage basin.