Are the aquatic systems affected by acid rain today?

Of course they are. Everything in the environment is affected, actually. But focusing in on the aquatic systems I could give you more information. First of all they are GREATLY affected! The acid...

YES

It is most affected in the U.s and Canada. Mostly in states/cities that have lots of factories.

mostly freshwater fish as it contaminates water.it contaminated water for all animals thus poisoning most animals.

Burning coal and burning gasoline produce certain combustion byproducts, particularly nitric oxide and sulphur dioxide, which when dissolved in water (such as rain) become strong acids, nitric acid...