In fishing some lakes near DFW the last few months I noticed on livescope a lot of scattered bubbles streaming up from the bottom of the lakes. These were in areas of flooded timber where I mostly fish. This situation has occurred both prior to turnover and now in turnover. In some places the stream of bubbles is so thick I can't easily make out the fish and move on. Does anyone know what these bubbles typically are (air, CO2, methane, other)? If air, I would imagine that the extra oxygen might be a plus and perhaps actually attract crappies and their quarry. If CO2 or methane (from leaking of subsurface hydrocarbon deposits or decay of bottom vegetation), I would imagine the opposite situation. I saw and caught some fish in the areas near significant bubble streams so I'm not sure what to think. Anybody have experience with this or knows the science behind it?