Salmon go down the tubes – literally
Washington biologists test pressurized tubes to transport salmon over dams.
Many Pacific Northwest dams, both large and small, lack fish ladders – effectively closing off hundreds of miles of habitat to endangered salmon and steelhead runs.
Now, biologists in central Washington are testing a new technology they hope could eventually transport salmonids to currently unreachable rivers: vacuum-pressurized tubes.
The tubes can fling fish a hundred feet in just a few seconds, but before whisking live fish over a dam, scientists must first try to send them safely across a room.
In early June, Yakama Nation Fisheries staff hand-fed about 90 wild spring chinook destined for broodstock into a vacuum tube. The pressure difference inside the flexible tube pulled the fish along, moving them from the collection area to a tanker truck waiting outside, which then transported them to the hatchery. The tube is less stressful for fish than moving them by hand, because it minimizes human contact and returns them to water faster.
The technology was dreamed up in 2009 by Whooshh Industries, a Washington company that originally developed vacuum tubes for the fruit industry. Whooshh is now working with tribal, state and federal partners to implement and improve the system. More tests are planned to ensure that it doesn't harm fish or their offspring.
"The ultimate goal would be to get fish to places they haven't been able to access, like the upper Columbia," says Todd Deligan, who runs Whooshh's fish-transport program. "But that's a very long-term goal. We're not going over Grand Coulee (Dam) tomorrow, that's for sure."