Bryan, my sympathies.

I did some research over the winter on how geese affect the pond. Specifically how their droppings affect water quality. Here's some food for thought and the main reason why I don't allow them to spend much time on my pond.

Every day each goose will poop enough excrement to grow 115 pounds of filamentous algae.

In my pond, I allowed a pair to nest on the island and raise a family. One year they invited about 40 relatives for a party, and the year after that I had Eurasian Water Milfoil growing in my pond. I imagine that one or more of the party goers brought some seeds in their gut from a local lake and deposited them in my pond. So now I have to treat my pond every couple of years with Fluridone to kill what is growing. Every year I think I have it eradicated, and then every few years it shows up again. I (and Kate the Springer Spaniel) are busy this time of year keeping the No Vacancy sign lit and operating.....