Are the fibers exposed on the surface or are they fully encapsulated in the epoxy/varnish. If the fibers are exposed, it means someone sanded into the glass. If they're encapsulated, it means the glass wasn't properly wet out and is probably delaminating from the wood. Either way, the glass will need to be replaced, but as Paul said, it can wait until the end of the season. However, I would cover exposed fibers - if there are any - with a coat of varnish to prevent the problem from getting worse.