Jim,

Dams can and do destroy multiple wild runs at a time. It has already happened, and more could wink out if safe passage conditions are not required. What makes you think dams will be continued to make improvements in passage? The current surge in improved fish passage is caused in large part by ESA listed fish. I don't think nets have extirpated many fish runs, altho a few smaller ones may have been or nearly so.

Now, again, why are nets more important?

Sincerely,

Salmo g.