Saw this comment on the WA Fly Forum and thought you may enjoy......
Russia has some interesting fish hatcheries. At one processing plant they dug out a tiny fish less trickle at the mouth where it's tidally influenced. They pump it full of smolts and wait. At low tide the returning salmon pool up waiting for more water. As the pool fills with water the salmon follow suit and with a big hose and a vacuum system they suck the salmon out of the hole and pump them into an RSW tank before moving into the factory to be processed. No fishing required. Fresh fish without net pens, without by catch and without the operational costs of running a fishing vessel. They have a vodka distillery on site, drink til they can't stand and count money all day. Gill nets are old news.