We've had the same problem in our pond when we stocked brim. They revert to sunfish and multiply every month. Two suggestions:

1. Bait - don't laugh. Those pesky little bream will fight over whole kernal corn from a can. One on the tip of a very small brim hook will get it every time.

2. You're bailing out the boat and it's got a big ole hole in it. You're going to have to seine all those brim out of there or bait fishcages for them, one or the other. []

Then don't ever put any bream back in there until a professional fish hatchery can give you a balanced count per acre of what fish need to be combined and which don't.

Hope this helps, been there, done that, no fun! [:@]