Its a matter of proportion. Geese certainly do generate 1 lb per day per bird. But, depending on surface area and depth, there is an acceptable number of birds , especially if they are seasonal.
If you put in a floating island you create a safer habitat for breeding and also introduce some aquatic plants that will counter the clouding issues. Properly done, the floating island becomes an attractive platform for cover for mating pairs. The idea is to give a group of 8-12 ducklings a chance to survive at 70% survival rate until they imprint on YOUR property and then come back the next season. Sometimes that happens the first year, sometimes it takes 5 years or more. but the floating islands increase your odds significantly.
Another advantage to having some POOP? Geese Poop especially seals the pond better than bentonite. However we saw a pond in Weatherford Texas with dozens of domesticated ducks and GEESE. The pond was only about 40' X 80' and 7 feet originally. But the year round birds: stomped every bit of nearby ground bare. Plus their Poop added up to be quite a bit if you get overpopulated. This particular pond had nearly filled, and what was 7 feet deep, had become literally 4".
Ponds of more than an acre can support a few dozen for a few months.
ThomasTponds.com
