STN/RTN birds nest with black spots?

[csb123]

Hey all, I have a couple of small birds nest colonies that STN’ed. What I discovered today were these black things attached to the skeleton.
They don’t move. A couple fell off when I shook it, but most stayed attached.

I assumed the STN was related to my nitrate bottoming out 2 weeks ago. I have since corrected it.

Please tell me these are NOT a parasite.

 

[Big G]

Bump

 

[Backreefing]

Shriveled up dead polyps probably.

 

[csb123]

I’m starting to think that too...thanks. I broke open that frag and most of the spots are partially imbedded in the skeleton.