I love those pics from ewest for people adding cedars, but couldn't remember where to find it to post.
Yes, "permanent cover" is nice. However, we don't know exactly what the fish in the pond prefer. At some point, I assume some fish will find the state of the cedars to be absolutely perfect. At a later point of decay, perhaps some other species of fish will find that degree of cover to be perfect.
For people with cedars in their pastures, they are hard to beat as one important type of cover in a pond. (If you don't have cedars, you can frequently grab as many Christmas trees as you want from the drop-off locations before they go to the recycling center.)
