JD you are learning first hand why green sunfish are usually considered undesirable. As I see it, with a pond your size, you have about 3 options; individually or in combination.

1. Add more bass to effectively prey on the abundant sunfish. Buy and stock bass that are about 2.5 to times longer than the most common sized greenies (prob. 6-8" bass). As bass grow and continue to thin the sunfish you will have to thin their numbers. Ideally you should be removing the largest bass and adding smaller bass until the green sunfish are again rare in your catches. Small and medium sized bass will tend to select vulnerable greenies as prey items before bgill and larger shiners.

2. Start an intensive program of using traps (1/4"-1/2" mesh) to selectively remove green sunfish. Release desirable fish back into the pond. Green sunfish readily enter fish traps baited with bread. This can assist bass in reducing greenies.

3. Kill off all the fish the pond and start over.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management