

Impact on Fish
As the rivers become more acidic, the problems with acidification of waterways are:
Biodiversity Reduction
As the acidity becomes significant, the life that the river can support is reduced to the more resilient fish.
Acid Shock
Recall that not only can rain be acidic, but hail and snow too. When spring arrives the snow melts. If the snow was acidic, then there can be an acid event that can kill many of the fish in the stream. This tends to happen in streams because of the dilution factor in some of the rivers. The technical term is an episodic shock (or acid shock).
Aluminum
There are all sorts of metals and minerals in the rocks and soil that are dissolved by the acidic water and washed into the streams. Aluminum (Al) is of major concern as it can interfere with the breeding cycle.
Mercury
There is also mercury (Hg) that is dissolved by the acidic water, washed into the streams, into the fish food, and into the fish. The issue is not that the mercury impacts fish, they don't care, but we should if we eat the fish. Mercury concentrates in the liver! Bears, Eagles, and other animals that eat the contaminated fish are also at risk. See the U.S. EPA Website on Mercury for more information if you are interested.
Impact on Trees
The impact on trees is dependent on the acidification, type of tree, and interaction with the tree. The acid deposition can attack the leaves; sulfate aerosols lie on the leaves like a layer of dust (ever dust your houseplants?). Regional haze reduces the amount of light reaching the trees. Nutrients can be washed out of the soil. An acid fog can be in contact with the trees for long periods of time. Aluminum uptake is also a problem for the trees! Certain trees are more susceptible, however, and it is not uncommon to see what appears to be a healthy forest only to find an obviously distressed forest higher up (when the tree type changes).


Trees are under attack from the rain and the fog directly but of greater concern is the loss of nutrients from the soil and the aluminum which the tree can uptake. Certain trees are impacted more severely than others.
Impact on Statues
Coming from the UK, I have seen a great deal of acid deposition damage. We used a great deal of limestone in our building and for decorative structural features, including statues (marble is by far a more expensive medium but is slightly more resilient). Limestone is common in PA and in large areas of the UK. Chemically it is CaCO3, calcium carbonate. It easily dissolves in slightly acidic water (stalactites and stalagmites are lime [stalactites are the ones that grow down, think tights go down!]). If you are interested, visit the Great Basin National Park website for some beautiful images of stalagmites.
When limestone is dissolved it forms calcium oxide (CaO) which is lime. (This is like the part in the movie that seems to be extraneous information but is important later on in the movie). One way to treat acid streams is with lime.
Unfortunately, many statues, countless gravestones, and the information they contained have been lost due to acid rain exposure. The acid deposition has "eaten away" the limestone. We now use special paint on our automobiles to protect the paint from acid damage. It costs about $13 more per car, but think of how many cars there are! How much is the loss of a statue? How much is the loss of a healthy stream in PA?
