I do fly the drone at dusk and dawn as much as possible. I've caught bass blowing up on something a few times but never was close enough to tell what it was.
It is already pretty enlightening to see what images you have been capturing with your drone! Also, excellent job tracking your fish culling efforts. IMO you will be capable of observing the future population changes in your pond just by comparing your data over time.
However, clearly this is the time to deploy combined forces for your operations. The aerial drone needs to record the bass/forage interactions. Your boat drone needs to then sweep through the area with a net to collect samples of of the forage. Your submarine drone can capture underwater video of the interactions from a different point of view.
