Looks more like fungus growing on detritus than eggs. its possible the shrimp or the fish dredged it up from behind something and then the current moved it to where it's at now.
Just feeding in general will cause this. Detritus is made up of decaying organics (fish food, fish waste, plant matter, etc.) and will build up over time. the best thing to do is suck it out of the tank with each water change. It's not directly harmful to fish, but the byproducts produced by the bacteria are.Thanks for your reply. I managed to vacuum most of it up and hopefully it won't see it again. Would it be overfeeding that caused this?