How to help the fish overcome difficult areas? With… the salmon launcher Although it sounds a bit drastic, the idea we first heard about in 2014 works and is in fact a safe system to help fish that would otherwise get stuck in river obstacles.

Today we learn that the second version of the Salmon Launcher is entering the use, it has been improved and offers several key advantages. Whooshh Innovations based in Seattle is responsible for creating the Whooshh Passage Portal, because it is really called. How does it work? The system consists of a flexible plastic tube and a motorized air pump - one part of the tube is located at the bottom of the river and the other above the water, allowing the transport of fish through blocked or extremely difficult parts. secret sites the system was originally designed to load fish onto trucks or to a hatchery, but back then it had some drawbacks, such as the need to manually load the fish, which were then "fired" at a speed of 5-10 m / s.

And although the whole thing was cleverly designed, it required a lot of time, and was stressful for the fish. Therefore, engineers did not stop looking for a way for the fish to voluntarily enter the structure and they succeeded - it was enough to put a gutter at the end, from which water constantly flows out. Fish that are used to swimming upstream are immediately lured by this spot, and once they get there, there's no turning back. They enter the tunnel, slide to their destination (while maintaining the right pressure and humidity), and in the meantime, 18 high-quality photos are taken, which allows them to know the species, size and characteristics of each individual.

So the Whooshh Passage Portal seems to have only advantages. It helps fish overcome difficult areas and helps biologists who, thanks to this kind of monitoring, know very well what and how many fish are in the river, and they can remotely "refuse" entry to undesirable species, e.g. invasive ones, redirecting them back to the river. The solution is now successfully used on the Fraser River, which is the longest river of British Columbia in Canada, measuring 1,400 km. Moreover, tests are underway to verify that it can be used to remove invasive Asian carp from the Illinois River.