Thought this was a very cool video and article of when this years juvenile shad return to the ocean and how organization determine the strength of the spawn or young of the year index. Article in attached link:
https://www.lehighvalleylive.com/new...ease-them.html
Other benefit is there's millions of fry very similar to lake herring making the track downstream and if you locate the schools, everything in the river is feeding on them. You'll see them skipping on the surface, more early and late in the day, not hard to find. Find a plug that imitates 2-3 inch shad fry and you won't be disappointed. I use a shallow running Rap that's a perfect imitation and have had epic days with walleye and small mouths during their journey downstream.
Interesting read and video.