Freshwater acidification

[2] A well-documented case of freshwater acidification in the Adirondack Lakes, New York, emerged in the 1970s, driven by acid rain from industrial sulfur dioxide (SO₂) and nitrogen oxide (NOₓ) emissions.

When sulfide minerals such as pyrite (FeS₂) are exposed to air and water during mining operations, they oxidize to form sulfuric acid.

However, low-alkalinity regions (e.g., with silicate bedrock) lack the natural buffering capacity to neutralize incoming ions, leading to rapid pH drops.

The thick layer of sphagnum restricts the exchange between surface water and sediment, further contributing to reduction in nutrient cycling in the ecosystem.

[16] However, most aquatic species, such as clams and snails, are unable to withstand low pH levels which negatively impacts their growth and survival.

[17] Establishing riparian buffer zones—strips of vegetation planted along water bodies—can also help to filter pollutants from agricultural fields before they reach freshwater systems.

[22] Another important factor to consider when looking at reducing freshwater acidification are the choices people make to protect the environment everyday.

[26] Also, governments could invest funds to subsidize companies to decrease their pollution and incentivize them to use innovative methods of production, to lower both greenhouse gas emissions and the amount of acidic substances created.

Furthermore, government institutions across the globe can connect on the issue of acidification and work together to find a feasible solution through international agreements.

[3] Winds carried the pollutant from Midwestern United States to the Adirondack region and decreasing the pH level of water bodies and surrounding soils.

[29] The acidification of waters resulted in a significant decline in aquatic biodiversity, including the disappearance of fish and crustacean species.

[30] Several efforts were made to recover the environmental condition of Adirondack lakes by reducing SO2 and NOₓ emissions through the Clean Air Act 1990.

[3] Monitoring data shows improvements in water quality, although many ecosystems remain vulnerable due to the long-lasting effects of acid deposition on soils and watersheds.

[31] This case demonstrates how the Clean Air Act have played a role in addressing the anthropogenic causes of freshwater acidification.