Vacuum pressure may someday pull salmon over dams
The vacuum system being tested at the Roza Dam has the potential to move fish significant distances, and some believe the technology could be used to move live fish even over some of the region’s largest dams that lack fish passage, such as Grand Coulee.
YAKIMA — How fast can a coho go?
With experimental new fish-passage technology being tested at the Roza Dam collection facility, the fish can easily break 10 mph, zipping 40 feet in just a couple of seconds.
Using vacuum pressure — a flexible sleeve and gentle suction — a live fish can be safely whisked across the room and into a tank of water.
The 40-foot-long tube at Roza, 10 miles north of the city of Yakima, is part of a pilot project that will allow Yakama Nation fish biologists to study whether the transport causes any long-term problems for the fish.
“We’re trying to provide a cost-effective way to move fish over barriers,” said Todd Deligan, vice president of the fish transport division of Bellevue-based Whooshh Innovations. The company’s vacuum technology was created to transport fragile fruit during harvest, but a couple years ago, it decided to see if it could be used for live migratory fish, he said.
Installed this month, the biologists and engineers were testing and tweaking the new setup on Thursday with one coho, running it through the tube again and again, and it didn’t seem to mind.
The real test will be this spring when thousands of chinook run through the facility’s fish collection system, being identified and weighed by biologists before heading upstream.
Yakama Nation research scientist Mark Johnson said that using the vacuum transport system will save his team time: Sending the fish into the tanker truck through the tube is much faster than the current method of carrying them by hand. More importantly, it should reduce stress on the fish by getting them back in the water faster.
But the biologists and the Whooshh engineers agreed that in the long term, they are thinking about big-picture applications for this technology: next-generation fish passage.
“We’re excited about using something like this to get fish into reservoirs, over the dams,” said Dave Fast, senior research scientist for the Yakama Nation. “It could be a cost-effective and time-effective alternative to trucking fish in.”
Constructing traditional fish passage is expensive, especially for reservoirs with fluctuating water levels. The new fish passage planned for Cle Elum Dam, for example, will cost nearly $90 million, and that’s just to get fish out. To get the returning adults back in will still require driving them from the collection facility below the dam up to the lake.
The vacuum tube system, which relies on a generator to create suction, is basically just a soft, flexible sleeve inside a protective plastic pipe. When wet, the sleeve seals around the fish, so very little pressure is actually required to move them. When this reporter stuck her hand in, it felt like far less pull than a vacuum cleaner.
A physiological study done by USGS scientists at the Columbia River Research Laboratory found no negative impacts on the fish from the technology.
The vacuum system has the potential to move fish significant distances, horizontal and vertical, Deligan said. His company installed a 230-foot long system to move dead fish at a processing plant in Norway earlier this year.
He believes the technology could be used to move live fish even over some of the region’s largest dams that lack fish passage, such as Grand Coulee.
For now, the Yakama biologists will feed fish into the system by hand, after checking their vitals, but eventually, Fast said, the system could be designed so that fish swimming upstream would head directly into the tube.
Interest in the potential for the technology is building around the region, he said, but this Roza pilot project is the first step.