What plants or living organisims does acid rain effect the most?

Most of these will be in water including, Bass, Trout, Snails, Clams.

Acid rain affects almost every organism. In fact, it also affecs non-living things such as the marble of Taj Mahal. However the most affected are crop plants like cotton, rice, wheat etc., and Large trees. Worst affected animals are mostly aquatic animals and also some tertiary animals which depend on lakes for their water supply.