One of the constantly circulating stories in fish culture is what happens when effective predator netting is installed over rearing raceways/ponds. In more than a few cases the pond has "rolled" due to low DO as there were too many fish in it. Complete unawareness of how many were removed by birds, snakes, rats, and other fish eaters.

QC is difficult in the ponds as is simply getting a good count. To do so (good count, good control, good anything) takes money and commitment to success. WDFW seems to have little of either any more.