Gizzard shad- Where do they roam?

After talking to one of the better muskie anglers in Central Illinois, who fishes shelbyville 2-3 times a week. He has not seen the large schools of the gizzard shad in long time. We are curious , if any one else has seen the larger schools,of gizzard shad. What about their spawning habits?As well as the forage and or temperature range they seek to survive?
We had also heard that there is a good possibility ,of stocking shelbyville with the Hybrid Stripper Bass. How do you anglers feel about this , and would help the fishery.