Your fish will not starve as there's plenty for them to eat in the pond. You
were the victim of a predator, maybe a Heron, like we had several times in the
spring. Your fish are afraid right now, but will come around in another day or
so. We put out a scarecrow to keep the Heron away and so far its worked.
Unfortunately before we did that, we lost four good sized fish. Good luck.