The Chinook Salmon's Journey: Spawning at Feather River Hatchery [Video]

Where do California's chinook salmon come from?

We've all heard the story about the salmon's migration -- how young fish just a few inches long travel from the streams and rivers where they were born out through the Delta, San Francisco Bay and the Golden Gate. And we know how, usually after a few years of voracious feeding out there in the Pacific Ocean, the big strapping salmon -- the largest chinook ever caught in California was 88 pounds and about four feet long -- return to their natal streams. There, they spawn in cold water and clean gravel. Then they die, but the age-old cycle is renewed.

That story is true -- but there's something more to it. Chinook salmon have faced a host of challenges as California has become the most populous state in the nation and developed the country's biggest agricultural industry. Since both cities and farms need water, and plenty of it, virtually all of the great rivers that have been home to salmon have been dammed and developed. Salmon on the Sacramento and San Joaquin rivers and their tributaries have long since been blocked from most of their spawning habitat.

And because of that, hatcheries play an essential part in the chinook salmon's story. That's a chapter that not too many people get to see, but it's on display each fall in hatcheries up and down the Sacramento Valley. One of those facilities, the California Department of Fish and Wildlife's Feather River Fish Hatchery, is the destination of tens of thousands of homeward-migrating chinook every fall.

The arriving fish are blocked from moving upstream by an artificial waterfall, so, following their instinct to keep heading upriver, they enter a long fish ladder that leads to the hatchery building. There, workers in a kind of disassembly line take over the job -- spawning -- that the fish would normally take care of themselves. Fish are anesthetized with carbon dioxide, then killed and processed. Workers harvest eggs from female salmon, about 2,000 per fish on average, and then fertilize them with milt collected from males.

The state's federal and state hatcheries produce about 30 million salmon each year -- a process that's crucial to continuing the state's commercial and recreational fishing industry, since only a handful of wild-run salmon survive.

“It’s not overstating it to say that if we did not have the hatcheries, there wouldn’t be any salmon in the river. I mean there just wouldn’t,” says Andrew Hughan, a Department of Fish and Wildlife public information officer.

The fish that make it back to the Feather River hatchery and similar facilities have survived against long odds. Typically, about 99 percent of the juvenile salmon die. The young fish are not great swimmers, so many become meals for predators. In California, the trip through the Delta claims many seaward migrants who take wrong turns in the maze of waterways and become "entrained" by the big pumps shipping water to the San Joaquin Valley and Southern California. Many fish die at sea; many are caught; many more die during the upstream migration.

But from the 1 percent that do return, much can be learned. Many hatchery salmon, including those spawned at Oroville, carry data chips inserted in their head before they're released in the spring. Chips collected from returning salmon can yield valuable information such as a fish's age and where it traveled during its ocean migration.

Gathering this data, Hughan says, is integral to the preservation of the California chinook salmon.