From the Seattle Times:

The Puyallup Tribe is working on some innovative ways to boost fisheries on hatchery chinook destined for the Lower Puyallup River, while still raising efforts to protect wild chinook.

At the tribe’s new Clarks Creek Hatchery, biologists created rearing ponds that simulate a more natural setting with tree-root wads and gravel to boost young chinook survival.

“Chinook born in the wild develop instincts that help them avoid predators and find food,” said Blake Smith, a tribe hatchery biologist. “Unfortunately, this isn’t something we see a lot of in hatchery fish raised in traditional, almost featureless, cement ponds. The more these fish learn to survive in the wild, the more hatchery fish that will return to the river in a few years.”