The picture you present here is not in a good quality. Hopefully u dont get mad with my bad quality comment
If my sight is correct, fish eyes will not give this kind of effect. This is the ink problem. When we talk about ink, there are many things can be upfront.
This distribution factor caused by - Ink is too heavy and not wetted properly, or maybe ink too short and dry. mostly we add good wetting litho varnish to reduce viscosity and lengthen ink.
It could be the improper roller and pressure settings. Check roller stripe and packing. Adjust it necessary.
But spots may come from moisture. The vapors will give the screening effect during the ink-jection process. To overcome, use heater on delivery or store stock in warm place.
Ok i hope this is too much. hey,this is not your problem anyways. why bother?