poland_jack,

Natural vs. artificial cover is a gray area.

Here are a couple considerations that I use:

1) Depending on your water clarity, you may or may not be able to see the structure you put into the pond. If your water gets very clear (and depending on the depth you place structure), you may not want to put something in that looks ugly sitting on dry land.

2) In my experience, whatever you put in will eventually get "scummed" up with slime coatings which may then obscure the "image" of the junk. If you put an old white refrigerator, the white color will eventually be replaced by the slime color.

3) 90% of any cover/structure you use is going to end up snagging fishing lines/lures, so I don't use that as a prevailing concern.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."