Ever since rivers have been dammed, destroying the migration routes of salmon, humans have worked to create ways to help the fish return to their spawning grounds. We've built ladders and elevators; we've carried them by hand and transported them in trucks. Even helicopters have been used to fly fish upstream.
But all of those methods are expensive and none of them are efficient.
Enter the salmon cannon.
The device uses a pressure differential to suck up a fish, send it through a tube at up to 22 mph and then shoot it out the other side, reaching heights of up to 30 feet. This weekend, it will be used to move hatchery fish up a tributary of the Columbia River in Washington.
The device was developed by Whooshh Innovations in Bellevue, Wash. CEO Vince Bryan tells NPR's Linda Wertheimer that the word "cannon" is a bit of a misnomer: the device looks like a cannon, and shoots fish out like a cannon, but unlike the weapon, this device is designed to move items gently.
Bryan says that despite their journey — which takes them out of the water for the duration of their flight — the fish don't seem worse for the wear.
"From the very beginning of the test that was a concern," Bryan says. "It may be just ten seconds to go as much as 250 feet ... [but] there seems to be no effect. The fish enter the water and swim away."
Compared to scaling a 350-foot high dam, it's a relatively easy way to get from point A to point B. The cannon that went operational this weekend is being used to transport hatchery fish, but state agencies are studying the cannon to see if it can be used in rivers where federally protected species of wild salmon are migrating.
Bryan says his company's vacuum technology was originally designed to transport fragile fruit in Washington's apple and pear orchards. Whooshh created a vacuum tube that allowed pickers to drop the fruit into a tube attached to their waist, where it was sucked up and sent down the line — all with no damage to the fruit.
In fact, a lot of things were sent through the vacuum contraption before salmon, Bryan says, including potatoes — with a French fry cutter on one end of the tube.
"So the potatoes went through the tube as a whole potato and when they came out the other side they were French fries," he says.
They've also had human volunteers, although Bryan says that the company hasn't created a tube that's large enough.
"There really is no limit to what we can move," he says.
He says the physics works the same whether it's a fish or person — the tricky part is sticking the landing.
LINDA WERTHEIMER, HOST:
This is WEEKEND EDITION from NPR News. I'm Linda Wertheimer. This is a story about the salmon cannon. Yes, you did hear me correctly - salmon cannon. And better than me trying to explain what it is and how it works, we've called up one of the inventors, Vince Bryan. He is the CEO of Whooshh Innovations, and he's in Bellevue, Washington. Good morning. Welcome.
VINCE BRYAN: Good morning.
WERTHEIMER: First off, I should say this is a serious invention for a serious problem. The numbers of wild salmon species have plummeted. In many places, dams block salmon migrating to their spawning grounds. Fish ladders are expensive and often don't work. Where there are not ladders, fish have to be trucked or even helicoptered over the dams. But Vince Bryan, you came up with a different way to move fish. Can you explain what the salmon cannon is?
BRYAN: The salmon cannon is really a device that we have created to move objects gently. And it works by a pressure differential. And so it's a misnomer in that respect. It looks a little bit like a cannon, but the fish do move very quickly. And they come out of the end back into the water as if they were shot out of the end of the cannon.
WERTHEIMER: What I don't understand is why you think that these fish are fine after they come out the end of it. I mean, they come flying out.
BRYAN: In reality, from the very beginning of the test, that was a concern. Can the fish be out of water - although it may be just 10 seconds to go as much as 250 feet? But the fish handled that very well. And so there seems to be no effect. The fish enter into the water and swim away.
WERTHEIMER: Now as I understand it, you invented this technology for fruit - apples and pears.
BRYAN: Correct. The initial problem that we were trying to solve was how do we allow for picking of a piece of fruit, such that the picker isn't wasting so much time going up and down that the ladders? And that's what ultimately led us to the salmon cannon.
WERTHEIMER: So are there any other things that you have moved through the tube?
BRYAN: You know, we've been asked to put a number of things through. But one of the more fun ones that we did was we were asked to put potatoes through the tube. And at the end of the tube they delivered to us a french fry cutter. And so the potatoes went through the tube, and then - as a whole potato. When they came out the other side, they were french fries.
WERTHEIMER: Is it conceivable that you could move people in tubes like this?
BRYAN: Yes is the answer to that. And we've had a lot of volunteers along the way as we've been doing our testing. We haven't produced a tube that large yet. There's really no limit as to what we can move.
WERTHEIMER: I can think of a lot of problems of moving people in tubes. You know, things like high-heeled shoes or handbags or luggage or whatnot.
BRYAN: Well, now you're getting awfully big. You know, in theory, it would all work. The biggest concern from our perspective in moving a person is just what is the method of slowing that person down? It's not going to be moving them. It's going to be gently landing them.
WERTHEIMER: Vincent Bryan is the CEO of Whooshh. This weekend, the salmon cannon, which was bought by the Washington State Department of Fish and Wildlife, goes operational. It will be on a tributary of the Columbia River. Mr. Bryan, thank you very much.
BRYAN: Thank you. Transcript provided by NPR, Copyright NPR.