The widespread damming of rivers across our country has benefits. Dams give us clean water, hydroelectric power, crop irrigation and reservoirs to fish. But in damming a river, that river ecosystem is destroyed, and specifically in the Pacific Northwest, the spawning runs of salmon are interrupted.
Multiple species of salmon live most of their lives in oceans, only running upstream into freshwater rivers to spawn in the same spawning grounds where they hatched. When a dam is built in their way, it is devastating to populations.
Humans have tried many techniques for transporting salmon upriver around dams. Salmon ladders, elevators, hatchery trucks and even helicopters have been used to return salmon to their spawning grounds.
The latest innovation for getting salmon upstream has been billed as more efficient and less costly than anything else tried to date. The salmon cannon, developed by Whoosh Innovations in Bellevue, WA, literally sucks fish through a tube and spits them out the other end, presumably on the other side of whatever obstacle impedes their upstream progress.
A pressure differential sucks fish into a tube, where they reach speeds up to 22 mph before being pushed out into the water on the other side. Surprisingly, according to the company website, the process is actually quite gentle on the fish. The technology was initially developed to transport fresh fruits, which must be handled very carefully. Multiple studies have been conducted on live fish, and Whoosh claims that stress levels of the fish are not elevated in response to being transported through the cannon.
According to a National Public Radio interview with Whoosh CEO Vince Bryan, it takes about 10 seconds to move the fish 250 feet, during which time the fish is out of water. That’s a lot less stressful on the fish than being caught and released by an angler, and it’s far less strenuous than scaling a dam via a salmon ladder.
The device has already been used for transportation of hatchery-raised fish up the Columbia River in Washington. At this point, it requires a human to place fish into the conduit, but Whoosh is working on a system by which fish would enter the device by their own volition. According to the website, attracting salmon with water flow has worked to convince them to swim into the tube.
State agencies are currently studying the device for potential use on rivers with migrating salmon. More fish making it upstream to spawn means more reproduction and more fish returning downstream. This is just one more technique that could make a difference for our nation’s salmon fisheries.