Acid rain damages lakes and streams primarily by increasing their acidity, which harms aquatic life.
Acid rain, resulting from pollutants like sulfur dioxide and nitrogen oxides released from burning fossil fuels, doesn't just fall directly into lakes and streams. It also runs off the surrounding land after rainfall and snowmelt, carrying acidic compounds with it. This influx of acidity leads to several detrimental effects:
-
Increased Acidity: The most direct impact is the lowering of the water's pH, making it more acidic. A healthy lake or stream typically has a pH around 6.5 or higher. Acid rain can lower this significantly.
-
Harm to Aquatic Life: Many aquatic organisms, such as fish, amphibians, and invertebrates, are sensitive to changes in pH. As acidity increases:
-
Fish Populations Decline: Acidification disrupts fish reproduction, development, and overall survival. Eggs and young fish are particularly vulnerable. Some species are more tolerant than others, leading to a loss of biodiversity.
-
Other Aquatic Animals Suffer: Invertebrates, which are a crucial food source for fish and other animals, are also affected. The loss of these organisms disrupts the entire food web.
-
Aluminum Toxicity: Acid rain leaches aluminum from the soil into lakes and streams. Dissolved aluminum is highly toxic to fish, damaging their gills and affecting their ability to breathe.
-
-
Water Clarity: Ironically, acidic lakes often appear clearer because the acid kills algae and other organisms that cloud the water. However, this apparent clarity is deceptive, as it indicates a severely damaged ecosystem.
-
Disrupted Nutrient Cycles: Acidification can alter nutrient cycles in lakes and streams, making essential nutrients less available to aquatic organisms and further disrupting the ecosystem.
In summary, acid rain negatively impacts lakes and streams by increasing their acidity, mobilizing toxic metals like aluminum, and disrupting the delicate balance of aquatic ecosystems, leading to a decline in biodiversity and overall ecosystem health.
