Salmon cannon launches fish over waterway obstructions
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Flexible pneumatic hose helps flummoxed fish return to spawning ground at 22 mph.
If you’re a salmon, getting back to your spawning ground can be frustrating, given the increasing number of man-made dams and other waterway obstructions. Consequently, a Washington-based company – the onomatopoeically named Whooshh Innovations — is looking to adapt a its pneumatic hose system to give up to 30 salmon per second a 22 mph “toss” over such impediments.
Originally designed to gently transport fruit, the Whooshh systems’ is composed of a flexible hose containing a series of membrane-like circular baffles that conform to the fish’s body. This seal allows negative pressure to build, creating a vacuum that pulls the salmon through to the exit end of the hose. According to the company, the system can transport 40 to 60 fish per minute at an average rate between 5 and 10 meters per second (11-22 mph).
As rough as that treatment may sound, the company says moisture in the hose provides lubrication and the fish only experience 1-2 psi of pressure, which doesn’t damage delicate scales or eyes. In addition, the fish are only briefly out of the water during transport.
Due to the flexibility of the hose, Whooshh says it can currently extend to 240 feet and ascend to up to 15 feet with a minimum corner radius of 7 feet. However, since no water is being moved, the company says the hose has the potential to reach 2000 feet and a height of 1000 feet. The system is also low power, using between 5 and 25 kw, depending upon the quantity, height and length of transport.
To date, the system has been pilot tested in three central Washington state rivers by biologists who hope to reintroduced the species to currently unreachable habitats.