NARRATOR: Altogether, Columbia Basin hatcheries conceive in labs, raise in tanks, feed, weigh, measure, sort, track, count, and finally, release over a hundred million salmon every year.
But fewer than one percent of the juveniles we produce every year return as adults. It turns out there is much more to saving salmon than just making salmon.
Replacing salmon’s special genius with our own has resulted in extremely creative, and expensive, strategies for their protection outside the hatchery.
It begins with the challenge of keeping them alive on their journey to the sea.
The first threat to newly-released hatchery salmon is bad habits.
Used to being fed at the surface, many become food themselves.
Even the instincts they do retain from their wild ancestry might not be as relevant in today’s river.
DAVID DUNCAN: They used to travel from the headwater streams to the ocean, facing backwards. They were just, they just would hold their place in the current, and the current just swept them out to sea. Now there are eight dams blocking their journey that create four hundred and fifty miles of slack water, of dead water. So they have to turn around and swim facing downstream, burning up their energy. So it’s a really unnatural situation we’ve created for them.
A four-inch fish arriving at a 100-foot dam doesn’t have many good options.
Some juveniles get swept into the turbines that are generating electricity.
DUNCAN: The fish is suddenly shot down to a 110-foot depth. Think about how your head feels when you’re twelve-feet deep in a swimming pool. They’re under unbelievable pressure. They go through the turbines and they fly out into thin air.
Others take the plunge directly over the spillway.
Either way, a number of juveniles will die at each dam. And survivors often find themselves disoriented in the turbulent tailwaters below… where they’re easy prey for pikeminnow, a native fish whose population has exploded in the warm, slow water between dams.
A significant percentage of out-migrating juveniles perish at each dam. Idaho’s salmon run an especially deadly gauntlet on their way to the sea.
JIM MARTIN: The cumulative effect of eight dams saps the strength of these fish and causes delay in mortality. It’s the death of a thousand cuts.
Forty years ago, the U.S. Army Corps of Engineers and the National Marine Fisheries Service began an experiment that’s grown into a cornerstone of salmon “recovery” efforts: fish transport.
An underground pipe with an opening above the dam funnels fish to the site.
MIKE HALTER: This area’s the actual juvenile separator; this is where we split the large fish from the small fish. They go into a bin area and out through these two flumes.
A random sample is checked for the tags hatcheries implant in the noses of salmon, and then, they’re all transferred to a barge or a truck for the journey downriver.
Fifty million dollars a year has purchased collection, passage, and transport for as many as 20 million young salmon.
A few miles below Bonneville, the young salmon are unceremoniously flushed into the river.
Finally, what’s left of the hundreds of millions of salmon conceived in plastic bags, raised in tanks, fed floating pellets, and driven downstream, heads out to join the community of life at sea.
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