Why do some lakes become "dead" due to acid rain?

Lakes become "dead" due to acid rain because it lowers the pH of the water, harming aquatic life and disrupting ecosystems.

Acid rain is a result of air pollution, specifically from the burning of fossil fuels which release sulphur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere. These gases react with water, oxygen, and other substances to form sulphuric and nitric acids. These acids then fall to the ground in rain, snow, or fog, and can be carried by wind to bodies of water like lakes.

When acid rain enters a lake, it lowers the pH of the water, making it more acidic. Most aquatic organisms, including fish, insects, and amphibians, have adapted to live in water with a specific pH range. If the water becomes too acidic, it can be harmful or even lethal to these organisms. For instance, fish eggs cannot hatch at a pH lower than 5, and adult fish may die at a pH lower than 4.

Moreover, acid rain can leach aluminium from the soil around the lake and carry it into the water. Aluminium is toxic to many forms of aquatic life, especially fish. It can damage their gills, making it difficult for them to breathe and ultimately leading to their death.

The loss of aquatic life can disrupt the entire ecosystem of the lake. Predators that rely on fish for food may starve, and plants that rely on fish for nutrients may not grow. Over time, the lake can become "dead," with little to no life remaining.

In addition, acid rain can also affect the lake's water quality, making it unsuitable for human use. It can corrode pipes and other infrastructure, leading to increased maintenance costs. It can also harm crops and other vegetation, affecting agriculture and food production.

In conclusion, acid rain can have severe impacts on lakes, leading to the death of aquatic life and disruption of ecosystems. It is a significant environmental issue that requires urgent attention and action.