Sorry, but this picture really doesn't even fall into competition with some of the other entries. I like the idea of "man watching nature" (in a controlled environment), but the technicals are way off. It looks as though the picture was taken with a simple point-and-shoot camera, with no flash used.
This is very dark and unclear on my monitor. I don't think I will be alone in saying this, so perhaps you need to look at your own monitor calibration.
Far from a natural environment. A DNMC to me. I don't include man-made natural environments as part of challenge guideline, even though you may have interpretted it that way. Also, I don't believe sharks are mammals or amphibians.