My guess is that this standing body of water is covered in some type algae which has robbed it of oxygen. If I'm right about that then there really is no life here, just a still quiet dead pool.
I first noticed this while hiking through here and recently came back with my mountain bike and camera. Its inside a state park and there are several of these standing pools of water, but this one grabs your attention because there are no birds or life of any form and has this smooth velvet-like green carpet on the surface.
However in the hurricane season when we get torrential rains and a high tide at the same time these pools get reconnected to the bayou and probably come back to life for a short spell as the water becomes oxygenated again.
Anyway, there is a path around it and plenty of angles to look at this spectacle. With the bayou, mangroves and wetlands so full of life this presents an unexpected sight. It reminds me of the Tolkien Dead Marshes. In one sense it appears quite beautiful but I fear that if I get too close I might never be seen again. I can't help but let my imagination runs a little wild when I see sights like this. This is a real-life dead pool. Is that an oxymoron or what?