4th of July I went with my mom and her husband to the lake on his boat. This is a lake that I've fished from the shore/dock a lot before, but this was their first time there. We were back in an alcove that had been part of the woods that flooded so it had trees sticking out and a lot stumps under the water. They both got very excited with they saw a very large school of shad go under the boat moving from shore to deeper water.
I've been to this lake a lot, it's one of my primary go to places. I like to get out in the early AM at the dock and you'll see the shad on the top water. They'll turn sideways and skim across the surface like skipping a stone on the water. And you'll see these large groups of them running together at the dock holding a certain distance from the shore or moving from deep to shallow or vice versa.
So explain to me, these, shad, shinners, minnow... whatever they are called

What I am I looking for? How should I have approached this situation? In the early AM why are they on the surface?
The water was very warm +/-80, and they were moving shallow to deep, so that tells me they are moving to cooler water, and I'm sure we should have followed them that day.
Thank you very much for your input, I really appreciate it.
-James