They were successful, although they disturbed the catfish more than they would have liked. All of the cats were observed in areas where rocks were deposited on the river bottom from riprapped banks or from wing dams. However, Talbot pointed out that both flatheads and channel cats are native, and winter aggregations occurred before human engineers redesigned the Mississippi. Rocky areas were in the river naturally, although many of these areas have been. From their observations, the biologists are convinced that catfish require a silt free, level location combined with shelter from the current for their wintering site.
Strong currents are necessary to keep the area clear of silt.
In their dormant state, silt would cause the fish problems by plugging up their gills. Silt also harbors microorganisms that could cause diseases. Even in the chosen areas the fish had problems with fin infections in the silt free areas where the divers saw them. They also must have rocks to lie behind so they can hold a position without using energy. Isn't it hard to see how these findings reflect on the Corps' proposal.