If they're breeding/nesting at your pond each year - try finding and disposing of their eggs. They usually lay and leave. This way you will cut down on the population increases. If there are several generations of geese using the pond you'll have a very hard time getting rid of them with non lethal means
It's definitely several generations. The last 6-7 years there have been no less than 5 geese hatched and brought to adulthood anually.
