Is there any vegetation present for the FHMs to hide in?

My neighbor is currently doing a FHM/RES experiment is his one acre pond, not sure why he hasn't stocked anything else yet but this has been going on for fours years now. My wife and I fished it last weekend, we caught seven RES between 4" to 7", none of them appeared stunted but the smaller 4" fish were sporting spawning colors. Last weekend was the first time anyone had fished it since I brought over 60 to 70 RES fingerlings four years ago, he had previously stocked FHM several years before that. He has coontail and some sort of narrow leaf pond weed, we saw lots of FHM in and around the weeds. I will see if I can sample it again and report back on what I find.