It is hard to tell from the pictures. Can you describe it? Does it look l;like mold?

I would have guessed vermiculite. Are these trees new to you. If you have had them for a while did you mulch them with vermiculite. Have you had rain storms that my have floated the vermiculite out of its mixture and to the surface.

We live in SC we have had a great deal of rain and Hurricane they look like clear rubbery glass

Should I remove them

I would just reduce watering and they should return to their former size as the surface dries out.

They are probably distributed throughout the pot so they would be impossible to remove unless you re-pot completely. They are meant to assist watering potted plants but I haven't seen anything specifically about using them for citrus.

Thanks glad to know I haven’t damaged my trees