I went out to change the water and was standing on the berm, I guess fairly still and looking into the pond, and the turtle surfaced. He is really cautious and I tried to aim the camera without using the viewer (which didn't turn out well). Several fish were swimming around him but he ignored them and swam over to some vegetation and started nibbling on that (salad before the main course? I don't know.) Anyway he surfaced completely and swam out to where I could have gotten a great picture but when I moved, he was gone.
Is this naturally introduced predator a bad thing? The thought of him just randomly chewing on the fish isn't good, but is an ecosystem of organisms which doesn't have all elements of the predation system in place (due to overseer control), a healthy niche? He might stir them up, but that could be the difference between fat, lazy aquarium/zoo fish, and fish with real lives. I don't think I'll tell Bill about this "browsing in the noonday sun" habit yet.