Wow! 100 CC in a 1/5 acre pond is a little (actually a whole lot) high. At 3-4 inches some will be eaten by the bass, and there will be some natural mortality. When they get to about 4 inches and larger, it has been my experience that the bass don't seem to care much for them.
Channels cats grow very fast. By springtime, without supplemental feeding, they should be in the 5-7 inch range. By next August they will probably be in the 10-12 inch range. Being in NC, you may see some in the 16-18 inch range before it gets too cool to reasonably feed (water temp in about the mid-60s for me).
With that many cats added to a small pond, I would take out every one caught on hook and line. They become hookshy very fast, and they have long memories -- thus, the problem with that many.
It doesn't take too long, maybe two years, for them to become the top predators in a pond. At that point they will have grown to at least 20-24 inches.
I have a 0.7 and a 0.3 acre pond. I put channel cats in most every springtime. I've learned to usually just buy 25 4-inchers. About 15-17 go in the 0.7 acre pond, the remainder go in the 0.3 acre pond. I still end up with problems, as we can't always get them out before a few of them become huge, and then start causing problems.
Don't get me wrong. I love having the catfish. They grow fast. They are delicious. But, they can become real pests.
Good luck,
Ken
