A neighbor had two of the AFLAC white ducks (Pekin Duck) on his 1/2 acre pond. He kept complaining about how it was muddy all the time, and how the bank was eroding.
I watched the ducks one day, they kept going all along the shoreline digging in the dirt above the water line for roots of grasses and other things.
One night both ducks were killed by something. Within a few weeks his muddy pond was clear.
I never thought that just 2 ducks would do that, but it looks like they did.
Many of the ponds I fish host wild mallards and Canada geese. Some overwinter while others nest. I've noticed the mallards muddy the shallow areas considerably. There are a lot of submerged weeds in them which may help to keep the central portions clearer. I would think that any duck that tips to eat and will disturb sediments might contribute to muddiness.
