More than 100 years ago, rivers like the Cle Elum in the state of Washington were teeming with migrating salmon trying to get upstream to a lake to spawn.
The once plentiful fish, however, vanished when dams were built without any kind of migration passage. But salmon are coming back, thanks to aggressive human intervention.
CGTN’s May Lee reports.
A company called Whooshh Innovations has come up with a fish transport system that gives migrating salmon a free joyride over an impassable dam. It’s nickname The Salmon Cannon.
This portable system, costing around $10 million, about one-sixth the cost of traditional fish passages, uses a tube filled with air and water mist to safely transport migrating salmon more than a kilometer from the river, over Cle Elum dam and into the lake above.
The transportation begins when salmon swim upstream against the current and up ramp flowing with water. Once inside the system, the salmon swim through a small waterfall and into a chute, which then takes them inside a scanner that makes sure they’re actually a salmon.
The scanner sends the information to a sorting computer, which then switches a gate to either let the fish go into the Whooshh tube or into a holding bin because it’s not a salmon. This all happens in less than one second.
Once in the flexible tube, the salmon is shot through like a rocket at a top speed of 45 kilometers per hour. The entire bullet-train like journey, taking less than 60 seconds, ends with a final splash into the lake where the unscathed salmon swims off to spawn.
“The Yakima system historically had about 800,000 salmon returning here every year “, says Nicky Pasi of American Rivers. “That was the second largest run attached to the Columbia river itself and by the early 90s because all these dams were built without salmon and fish passage, we were down to three to four thousand.”
The return of salmon in the Pacific Northwest is especially important to the Yakama Nation, a group of Native American tribes that reveres salmon. They built their economy, religion and traditions around the salmon so when they vanished, it was devastating.
Whooshh is looking to help solve fish passage issues around the world as well. China, Southeast Asia and South America all have similar fish passage problems, which is leading to the extinction of a variety of fish.