You can buy a bundle of cedar shingles or shakes.....then go around the pond, and shove them into the bank at a 30-45� angle up from the bottom....maybe in 6-12" of water with the shingles under the surface. Space the shingles out about every 2ft or so, in several groupings around the pond.
Also, if you have access to large cobble or have some in the pond, you can lay down a loose bed of that and then cover it with limestone or shale slabs. The loose cobble will keep gaps open that the FHM can come under and use the slabs as nest sites. This may look a bit more natural than the shingles.
