Since only silver carp were affected, you can rule out water quality issues. You can rule out chemical spills. Basically rule out things that would have typically killed shad (easiest fish to kill) and all other species. The likely cause is a viral infection. It is possible that during the high water, a higher than normal density of silver carp came up the Cumberland River. They all congregated below the dam. With a super high density in a small area, a communicable disease quickly spread. This lead to the the fish kill. To possibly verify this theory, a few live but sick silver carp (fish found swimming lethargically) at the waters surface, where taken to Frankfort this afternoon. These fish will be examined by fish pathologist at Kentucky State University.
We talked to a few anglers fishing in the Tailwaters today (amongst the dead fish)... The report is Striped bass, white bass and catfish are still biting. One boat had 7 nice size striped bass in about two hours.
As for shad, my uncle had a recipie for them. He called it "planked shad". Nail the fish to a soft plank, and leave it in the sun. When the fish falls off the plank, pull the nail, take the plank in and eat it (all of the flavor, none of the bones).
An experiment by the feds? People are frantic trying to prevent them from entering the Great Lakes because they would destroy the lakes. Maybe the feds released a bacteria that only kills Asian carp.