At the river cabin, looking across the water, I could see rafts of shad. Thousands of baits in one school. This happens every summer.
When we catfish just one good castnet throw can get 10 lbs of bait. So my theory is I can castnet 100 lbs of shad, freeze them, and use as saltwater bait and chum.
Shad and menhaden are similar and salt water fish love menhaden. I once lived by a lake that had roach fish, i.e., wild shiners. I used those at PC pier for kings and spanish and bonitos.
We used to put them in a chum churn and they worked great! We froze them in gallon size ziplock bags. They wouldn't stay on the hook very well but they were great for chum.