Chinook born in the Nisqually River are being taken into protective custody by the Nisqually Indian Tribe.
The tribe is trapping and spawning natural-origin chinook this fall because so few have returned in recent years. Instead of passing naturally produced chinook above a tribally operated weir, the tribe will truck them to its nearby Kalama Creek Hatchery.
“We’re seeing a sharp decline of natural-origin chinook returning to the river, so we want to make sure these fish are as successful as they can be,” said David Troutt, natural resources director for the tribe.
At Kalama Creek, the fish are being spawned by hand. Their offspring will be released into the river next spring.
To make sure some chinook spawn in the wild, the tribe will release up to 600 adult hatchery-produced chinook into the upper watershed. That way, even more naturally produced chinook will leave the river next year.
“The genetic difference between natural and hatchery-origin chinook on the Nisqually is small,” Troutt said. All of the chinook in the river are descendants from an imported hatchery stock planted decades ago.
The native chinook stock was killed off in the 1960s in large part due to poor hydroelectric practices that left the river dry for months at a time.
Five years ago, the tribe began closely managing the mix of natural and hatchery-spawned fish in the river to help mitigate hatchery influence on the stock.
“Our goal is to let the natural habitat, instead of the hatchery environment, drive adaptation of the stock,” Troutt said. “By mixing in natural-origin fish at the hatchery, we bring in better genetic traits to improve salmon productivity. This means more fish for everyone.”
Recent declines in chinook productivity because of poor ocean conditions drove this year’s drastic action. “Instead of bringing in just a few, we need to bring in every single natural fish we can to protect them,” Troutt said.