It's not easy being a migratory fish these days. Not only do you have to deal with natural obstacles like bears, there are also man-made obstacles standing in the way – like 500-foot-tall (152m) dams. One enterprising company has figured out a safe and effective way to get around these problems: a fish cannon.
More than two dozen endangered and threatened fish species migrate along the West Coast of America, 12 of which return each year to the Columbia, Snake and, Willamette River basins to spawn. Environmentalists have been working for years to ease their journey, lobbying for the installation of various assistance devices at dams – from fish ladders and lifts, to trap-and-haul schemes where they're literally scooped out of the water, tossed into tanker trucks, and then dumped out further upstream. Unfortunately, very few dams in the region have actually installed these devices due to their high cost.
In the Columbia River, for example, fish ladders have been installed in a number of the region's smaller dams all the way up from the sea, until the fish hit the 236-foot-tall (71m) Chief Joseph dam. There, the fish must attempt to swim up through the turbines with no protection from the spinning blades or rapid water pressure changes. It's even worse at the 550-foot-tall (167m) Grand Coulee a few miles up river from the Chief Joseph. And for a structure that high, conventional assistance ladders simply wouldn't be feasible. But that's where the Whooshh transport tubes come in.
They work much like the transport tubes from Futurama. A series of evenly spaced soft baffles ring the interior of the tube, which enables the negative pressure within to gently pull the item along — be it an apple, watermelon, Rainbow Trout, or Sockeye Salmon — protected from bruising, or even touching the tube walls. This system is far less labour-intensive (and traumatising) for the fish than flopping up 500-plus feet of fish ladder.
The Whooshh team (with a second 'h' added in order to secure a unique domain name) is currently testing a prototype tube system at the Yakama Nations Roza Dam fish facility. The system lifts fish 15 feet (4.5m) over the course of a 230-foot (70m) pipe set at a 45 degree angle, and the pressure is strong enough to propel the fish through them at anywhere from 15 to 22 mph, until they rocket out the other end. And this is a fairly small-scale prototype the company is using. Eventually that tube will extend more than 2,000 feet (609m), climb more than 1,000 feet (304m) vertically, and even such objects straight up at 90 degree angles. Nuts.
What's more, the fish seem to be totally OK with being gently pulled through tubes. The team reportedly had little trouble prompting them to enter the tubes at the Roza facility. Now we just need them to make a man-sized version to replace all this damnable walking. [Whooshh via The Verge]