Is this something to worry about?

One of my hives bottom boards has these black dots. I washed them but they have to be scraped off to get them off.

I was on another forum and said it is normal hive debris some months ago. I am still concerned though because my other hive doesn’t have this. Hive looks normal otherwise.

This isn’t nosema or some other disease is it?

Some is debris but on zooming in I see there is also some SHB there. It depends where you are in Australia but on the Sunshine Coast in Qld if you have bees you also have SHB and in the warmer weather they can become an issue but can be managed.
Cheers