People who’ve seen the video always ask the same thing: what does the fish actually experience? Not what it looks like from outside the tube. What happens on the inside.
It’s a fair question, and it’s the one that matters most for anyone evaluating whether a fish cannon is a tool they’d actually use in a serious fisheries operation. The viral video answers the visual question. I want to answer the biological one.
When a fish enters the Whooshh system, it’s moving on its own. The ASPFishway creates an attraction flow that fish orient to naturally, and they swim into the entry point without any handling or external motivation. That volitional entry is important because it means the fish hasn’t already been stressed by netting, crowding, or air exposure before the passage even begins.
The tube interior is misted throughout its length. Embedded misting ports keep the surface of the tube wetted, which does two things: it keeps the fish hydrated during what is, technically, an air transit, and it reduces friction so the fish slides smoothly rather than scraping. The transport speed is approximately 25 feet per second. For most fish species, the entire transit lasts a few seconds.
What Does the Science Say About Fish Welfare During Tube Transit?
The salmon cannon nickname implies a violent ejection. The physics don’t work that way. The differential pressure driving the fish is approximately 1 PSI, which is low enough that fish don’t experience meaningful compression or decompression across the tube length. What they experience is a brief, cool, misted journey from one side of a barrier to the other.
A 2014 study funded by the U.S. Department of Energy and conducted by Pacific Northwest National Laboratory assessed adult Chinook Salmon transport through the Whooshh system. The study measured post-transport survival, immune response, and egg viability and compared outcomes to a control group processed through conventional trap and haul methods.
Here’s what the system avoids that conventional alternatives don’t:
- Net contact, which causes scale loss and fin damage at rates that accumulate across large population transfers
- Crowding in holding tanks or truck compartments, which generates cortisol spikes that persist post-release
- Air exposure during manual handling, which stresses fish in ways that show up in behavior and survival data weeks later
- Physical contact with human hands or equipment during transit, which is eliminated entirely once the fish enters the tube
How Does This Scale From a Hatchery Application to a Major Dam Site?
The same underlying transport principle scales differently depending on the deployment context. At a hatchery or river trap operation, the TUber mobile unit uses the SalmonCannon for hand-loading and MigratorTubes to move fish to a transport tote or holding tank above. A small crew can set it up in a day and move significant volumes of fish without the manual handling that conventional transfer requires.
At a major dam site, the PassagePortal systems use the same MigratorTube transport with a volitional entry point positioned in the river, an AI classification system that processes every fish individually, and a GateKeeper sorting gate that routes fish based on species and origin. The fish cannon concept scales from a portable transfer tool to a fully autonomous passage and monitoring platform.
What Does This Mean for Summer Operations Specifically?
Summer is when fish welfare during passage matters most. Fish arrive at barriers with reduced energy reserves after upstream migration in warm water. Every additional stress event in the passage chain compounds the physiological load they’re already carrying. A system that eliminates handling stress at the passage point is directly contributing to post-passage survival outcomes, not just to the passage count.
Visit Whooshh Innovations to see the full product range. For more on how fish passage technology is developing, read the published blog A More Natural Way Forward. To discuss a specific deployment, contact the team directly.
