At this time of year with the temperature's as they have been, The silvers will come together and form large shoals sitting in the warmest thermocline. On a pit i fish that is usually in 2 areas dependant on the wind direction, They sit at about 8 to 14ft down in 40 to 50ft of water, Sonar shows a large congregation of predators underneath them, The amount of predators on the surface in your pictures appears to be showing the same thing. This pit is around 3 acres, you can fish anywhere else on the pit and not even get a knock at this time of year.