Could be baitfish (most likely), but the sensitivity seems to be set pretty high as well. Tone that down and it may disappear, which suggests it could also be current if in the river, or weed bed if on a lake. My older Lowrance would do the same in turbulent water and no fish around. For a baitball, I'd be looking to see if I could find some larger returns in the same vicinity for those big eyes that are harassing it.
Looks like an older Lowrance unit, note what looks to be the GPS puck. So no downscan on this unit.
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Then again, there are times where I am pretty convinced I suck at interpreting my graphs.