Saw this on Reefbuilders the other day, thought I'd share 
One company is using fish cannons to safely get migrating fish through man-made obstacles. Salmon are curious creatures going from the saltwater ocean to travel hundreds of miles up freshwater rivers and streams to return to where they were born to spawn. Along the way, the salmon navigate through some serious obstacles with head-scratching amazement, but occasionally run into dams and other obstacles they can’t get around or over and that is where the Whooshh Innovations fish cannon can help.
http://reefbuilders....me-fish-cannon/
