Have to disagree with Theo's trama theory. I had 18 hours of near hurricane force winds with top winds of 120mph...winds which blew my feeder over into the pond....and it was chained down. One day after feeder recovery and repair and fish were feeding. Today (10 days after Rita), they are extremely aggressive, jumping out of the water to get the feed. No, trama isn't the reason, I don't believe.

The black water and 12 inches of visibility is the clue, I believe. The oaks may have contributed, but you may have some other contributor. Is there any way a toxic material may have washed into the pond? Is there anything in your drainage area that may have caused this?