very fine cob webs

[Spray]

just a quick question, i just noticed that on top of the mixture in one container there is what looks like very fine cob webs, i have not seen this before, i was wanting to know if (1)this will effect the growth of the seedlings in the container? (2) should i remove this container away from the other ones?(3) could this spread to the other containers?(4) what can i do to prevent this from coming back on the other containers? thanks for your time.