I don't know what Scottie made for egg incubation, but I did use the Vibert boxes back in the 1970s that kjackson mentions in his post. They work in streams that have very little fine sediment. When filled with eyed salmon eggs and planted in a typically degraded (a stream whose watershed has been logged) northwest stream, the boxes fill with fine sediment - even worse than naturally spawned redds - and the eggs suffocate and die.

The UW Fisheries Research Institute tried some "above gravel" incubators in the Skagit River also in the 70s to avoid or reduce the fine sediment accumulation. The eggs survive to hatch, but the alevines didn't have the necessary clean strata with minimal current velocity they need for developing into emergent fry.

As you can see, it's tough to improve on Mother Nature. We have our other extreme of completely artificial reproduction and rearing of fish, but come to find out, we have a lot of problems with that as well.

Somebody has tried everything that has been thought of, and varying degrees of success have occurred. Remote Site Incubators (RSI) of various sorts have proven useful and fairly reliable for certain species like pink and chum salmon that often spawn in clusters naturally and do very little freshwater rearing as fry.

Sincerely,

Salmo g.