From my lake diving days many years ago, I remember during the dog days of summer we would find the fish right around or in the thermocline.
I wonder if they dip in and out of the cooler water as needed to maintain their preferred temperature? Might be something to leaving at least one deep hole not circulated for that reason. A cool water refuge.
You will have some fun with the DO meter. I hope you learn lots and share what you learn here.
As far as low DO in the water/bubble plume that makes sense. I have noticed swimming when I approach the diffuser plume the water is significantly colder (summer time). So it makes sense that it is pulling up low DO water from depth. I suppose if there were enough or maybe excess circulation then there would be no temperature difference as the water would already be thoroughly mixed.
What is puzzling is why the small fish like the bubble plume so well. In the summer we would approach the diffuser bubbles on the boat and see small BG riding the bubble plume up from depth then disperse outward. It appeared they were riding the plume over and over, like making a game of it. Maybe they liked the cool water? Or the bubbles? Don't know. Just know it is a common sight during summer around the diffusers.
Last edited by snrub; 04/07/18 10:02 PM.
