I don't think it's just sediment removal they're looking at. It's the entire ecosystem. Sure, there are alot of things you can simulate in the lab, but you are having to place alot of faith on your own calculations and theories when you begin a simulation. There are too many variables that I can think of that would sway the data. The scientific community already have found flaws in their theories about recovery times. 22 years in geological time is absolutely nothing compared to the big picture. Actually, a geological study of 100 years is still a short time.

Again, this is my theory.

As far as the WDFW is concerned, any labratory simulations to observe their behavior would wind up with the conclusion that it is a chaotic entity that cannot be quantified.