In the winter time there is very little current and even though it is iced over, plankton will form under the ice in the top layer of water. During the spring, surface plankton is blown to the bank and the water is clouded with other debris from run off. The Kokes tend to hold in the depths for the first 30 days until the water temp rises towards the high 40's or low 50's where the plankton again blooms faster than the current and wind can move it. Also, the plankton in mass begins to "stack" up in certain locations and the fish begin to school in these areas. Even though we are seeing shoals or schools of fish right now, all but the 1 year old fish will leave these schools to go forage. As the stacking of plankton comes together the fish will rejoin schools in these areas.
This is the best explanation I can give you as to what happens in our area.