What the Heck is that?

Fished Catawba yesterday. We did terrible. No GpS posts cuz wouldn't want to send anyone to zero land. Yup! Zero, Nada, skunk! But now. To the headline. It looked to me like algae. So thick in current my analogy is a snowstorm under the ice. Friend had camera & said it was worse on bottom. Very strange. My guess is it is the algae bloom die off that fell and rested on bottom till this last big snow melt off & current came in like a back pack blower and is scouring out via current to the central basin dead zone. Your thoughts?

That doesn't sound good...ugh!