I've read about this, apparently they exist in a few places. Problem: fish need to travel to places where they lay eggs & so on, but find their route blocked b

I've read about this, apparently they exist in a few places. Problem: fish need to travel to places where they lay eggs & so on, but find their route blocked by a lock. And sometimes there are no ships passing through the lock, but fish that want to. Solution: an underwater webcam + remotely opened hatch. People watch the stream online, some fish appear, a member of the audience presses a 'doorbell' on the fishes' behalf, hatch opens & fish swim through.