Greetings from the American South, Perry! Like many here, I've always wished to visit New Zealand.
Regarding the watermeal, while it may shade the water & help shelter little fish, it also may heat it up by trapping more solar radiation. That's what happens here with floating plants such as water hyacinths.
Love the ducks! I've had a couple of them at my pond, but the geese tend to dominate.
