posted 6 years ago
I don't know if this helps you, but one of our mini-ponds, which gets runoff from the neighbour's horse paddock, grew a lot of algae mats over the summer. Last week I noticed a "wild" duck hanging out on it. By about the third day after she appeared, all the mats were gone. I can only surmise that she ate it.
The other small pond is not growing much algae. It's covered in azolla, though. I don't know if there's a correlation here.