Is it a connected wetland? If it is, trying to get a permit from DEP and COE for mechanized cleaning/digging of the pond area is going to be almostzerochance. If it is non-connected you probably won't have any trouble. COE and DEP don't care about ducks. I still think a pelleted herbacide (24D or similar) is your best bet, and no permits that I know of are needed.