I don't know that I have seen a study that shows how often the older female ovaries fail to this 'virus' or parasite. The mentions on the forum are more like it 'could' happen but I don't know that it actually happens with great frequency or with great infrequency. To say that any large female golden shiner must be sterile is kind of like saying that every nocturnal animal that is wandering around in broad daylight must have rabies. Probably a few do, but probably many more are still acting strange in the middle of the day but do not have rabies.
I too have adult GSH that are 6-8 years old and are 6-8" long. I have no predators that can eat them. I do have very few or maybe none? small GSH. However the same time the small size class of GSH disappeared my predators grew big enough to eat them.
So it may be that GSH eggs are viable but predators are consuming them.
I would assume 'sterile' could mean zero eggs or it could mean many eggs produced that cannot turn into living fry. I don't think the ovarian problem in GSH was from a chemical that impaired spawning but was from a parasite that invaded only the GSH ovary.
We should all probably try to find the actual studies
