We have a one acre pond in front of our house. The previous owner was an avid fishermen, and stocked it with all kinds of local fish. Everything from bluegills, to sunfish, to large and small mouth bass, to crappie, to grass carp, to blue and channel catfish. We have seen babies and juveniles of most of these, and the pond was last stocked 10 years ago, and so we know that they are breeding and so must be doing overall quite well. The pond is spring-fed, and is also fed with the run-off from the pasture above when it rains. In the very worst of droughts it will get down to 5 feet deep in the middle, but it mostly stays around 8 feet deep in the middle. I would really love to get some Muscovy ducks for our pond, the pond is just so dull without waterfowl. However DH is concerned that the ducks will harm the fish population, both by polluting the water with their manure and by eating some of the fish. Are either or both of these a real concern? How many ducks (i.e. duck poop) could a pond this size support, without negatively affecting the fish? And how avidly would the ducks hunt and eat fish if there is lots of cricket and grasshopper rich grass and clover surrounding the pond? I would really love some waterfowl on the pond, but not at the expense of the fish. Thank you to everyone willing to share their thoughts, I have learned a lot from this site!