My heart sunk when I saw the title. The base does look like it's been eaten away. Those little things look like more baby nudis, rather than eggs.
If you're not super attached to the coral it's probably easiest to just toss them and let the nudis die out for a few months before adding more SPS. If you want to keep them hit up Schnitzelreef for how to beat them. It took him months of dipping often to get rid of them but he did.