Black spots between silicone and glass?

[gilpi]

As the title says...I'm assuming these are gaps between the glass and the silicone? The black stuff is not on the outer part of the silicone.

 

[Autumnsky]

Yes, looks like the gaps are getting close to the seam. The blackish is algae I have a couple spots in one of my aquariums which have a little way to go yet, but resealing will need to happen eventually.