I use to fish for crappie at night at this time of the year in an old Strip Pit that's hydrologcially connected to the Ohio River via a creek and another creek when the river and creeks flood. So there are gizzard shad in the waters. They are attracted to the plankton that's attracted to the underwater light. They get close to the boat and swim in bait balls about 6 ft in diameter. I would think that a cast net thrown properly over them might catch some bait.