Effect of Acid Rain on Lakes and Rivers

It is in aquatic habitats that the effects of acid rain are most obvious. Acid rain runs off the land and ends up in streams, lakes and marshes - the rain also falls directly on these areas.As the acidity of a lake increases, the water becomes clearer and the numbers of fish and other water animals decline. Some species of plant and animal are better able to survive in acidic water than others. Freshwater shrimps, snails, mussels are the most quickly affected by acidification followed by fish such as minnows, salmon and roach. 

Lakes, rivers and marshes each have their own fragile ecosystem with many different species of plants and animals all depending on each other to survive. If a species of fish disappears, the animals which feed on it will gradually disappear too. If the extinct fish used to feed on a particular species of large insect, that insect population will start to grow, which in turn will affect the smaller insects or plankton on which the larger insect feeds.

Life of Aquatic Organisms:
 
Some types of plants and animals are able to tolerate acidic waters. Others, however, are acid-sensitive and will be lost as the pH declines. Generally, the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acid lakes have no fish.

The roe and fry (eggs and young) of the fish are the worst affected as the acidity of the water can prevent eggs from hatching properly, can cause deformity in young fish which also struggle to take in oxygen.The acidity of the water does not just affect species directly, it also causes toxic substances such as aluminum to be released into the water from the soil, harming fish and other aquatic animals.
 
Makes Drinking water unsafe:

Water that is slightly acidic should not be dangerous, as there are many foods that have low pH
value; for example, lemon juice has a pH of 2.4. However, a low pH can indicate that there may
be other contaminants in the water, because if pollutants have been added to a water source,
the pH typically will change.

Water treatment facilities monitor the pH level of the water while they are treating it for
municipal use. Acidic or basic water is harder to disinfect than water with a pH that is closer to
7.0. As well, if acidic water was sent through pipes and into homes, there would be a greater
danger of pipe corrosion, which could allow metals to dissolve into the drinking water as it flow
through the pipes. According to the World Health Organization, a pH less than 8.0 is necessary
for effective chlorination. If the pH is too high, water treatment facilities can decrease the acidity
in a number of ways. One common method that is used to increase the pH is to send the water
through a calcium carbonate filter, which neutralizes the acid and increases the pH of the water. Another common method is to inject a sodium carbonate solution into the water.