Actually it
preserves the realism that you cannot see any closer. If they could get closer to you, you could see the individual pixels that make up the texture (Realize that the textures are, for the most part, only 128 x 64).
Now, if you are running 1600x1200 on a 17" monitor, then that's like running at 140dpi or so. But if you ran 1600x1200 on a 19" monitor, then that's a bit more realistic.
If you want a close-up of the fish, press Ctrl-Alt-F.