I am assuming it is a grass carp, most states it is illegal to harvest and or be in possesion of them(transport) them. They are sterile and cannot reproduce(hence why that are protected). They were most likely put there by whom ever as vegitation control. Now even tho it is an HOA pond may be maintained by the state under a standard maintence agreement. If it is truly HOA maintained then they need a permit to stock it so talk to your fish and wildlife management officer and see if they can tell you who, what and why. Now depending on how smart the people are who dropped them in, they can be fine, keep it from becoming overgrown and clean or if they stocked too many they will clean it out. I have seen ponds with none, some and too many, the ponds with some usually fish the best, and the ones with no carp tend to get too weedy to fish. Even if the veg gets cleaned out it won't affect the fish(bass and bluegills), you will just have to adjust your approach. The pond that I fish that is cleaned out the fish tend to wonder, only hold to the few structures like culverts and fountains. moving plastics and cranks work.