Did you hear the one about shooting fish through a tube?
The “salmon cannon” may sound like something out of a Monty Python sketch—even its manufacturer’s name, Whooshh Innovations, is humorous—but the new technology could make a difference in the survival of endangered migratory fish.
The cannon, a vacuum-powered stretch of long rubber tubing that propels fish at speeds up to 22 miles per hour, has several applications, such as running salmon over a dam or efficiently separating hatchery-bred fish from wild fish as they return upstream from the ocean. (See the salmon cannon in action in the video below.)
“It may be funny, and it may sound ridiculous, but we’re dealing with the serious issue of fish and water usage,” said Todd Deligan, Whooshh’s vice president of fish transport systems.
Dams and salmon are an unfortunate combination. Dams block the migration of fish returning to their historic spawning grounds. Removing them has proven to be a boon to some species. But dams also provide hydroelectric power and water for agriculture.
“All those things are competing interests for salmon,” Deligan said, noting there are more than 80,000 dams in the United States and the vast majority have no form of fish passage, such as ladders.
“We’re losing huge numbers of runs because dams have no fish passage,” Deligan said. “This is a big opportunity to move those fish up the river.”
Fish ladders can help salmon get around such barriers by providing a series of ascending steps that they must leap to get to the other side of the dam.
But fish ladders are also hazardous to certain species, according to a study published in June in the journal Physiological and Biochemical Zoology.
When ascending a ladder, salmon engage in “burst swimming,” high-speed propulsion requiring more oxygen and energy, which can trigger cardiac arrest. “Migrants that elicited burst swimming behaviors in high flows were more likely to succumb to mortality following dam passage,” the study states.
Though cannons can cost $150,000 or more, fish ladders cost millions, Deligan said.
So far, the Bellevue, Wash.–based company has sold four devices: two in Washington state and two in Norway, where seafood processors use them to zap fish and fish parts around their plants.
The salmon cannon is now being used on the Washougal River in southwest Washington. There, migrating chinook are run through a narrow channel, where biologists from the Washington Department of Fish and Wildlife separate wild fish from hatchery salmon. (Hatchery salmon are distinguished by their clipped fins.)
State law prohibits crossbreeding between wild fish and hatchery fish. Until the launch of the salmon cannon two weeks ago, biologists trapped hatchery fish and placed them by hand in large containers. Forklifts then loaded the boxes on trucks to be driven to a hatchery.
Now they are vacuumed into the truck in seconds. The Yakama Nation in central Washington is also using the salmon cannon to separate wild and hatchery fish.
“It seems to be working way better than what we had in the past—way more efficient—and I think it’s more fish-friendly,” Greg Haldy, a state fish hatchery specialist, told King5 News.
Indeed, salmon exit the cannon unscathed. Whooshh originally developed the technology as a pneumatic tube to send harvested fruit from tree to truck. Even tomatoes survived the journey without a bruise, according to Deligan. “We couldn’t be in business if we were hurting things,” he said.
Back in 2009, Whooshh technicians were working on apple orchards along the Columbia River. “There were lots of stories about salmon issues all over the news,” Deligan said. “One of us asked, ‘Can we potentially put a migratory species through this?’ We all chuckled, but we realized we needed to try.”
Environmentalists seem to be embracing the technology.
“WWF prefers returning nature to a state where salmon can naturally run upstream to spawn and migrate back to sea,” Bill Fox, World Wildlife Fund’s vice president of fisheries, wrote in an email. “However, in the interim, WWF gladly supports any improvement...that results in greater survival.”
Such survival is Whooshh’s goal. “We’re hoping to increase the population by helping them get over the barriers,” Deligan said. “The more fish going up, the more little ones are coming down.”
“This is a serious issue, and we’re a serious company,” he said. “It’s not just about fish flying out of tubes.”