In many parts of the world, naturally occurring acid lakes have been known for more than a century. However, it appears that certain lakes have turned more acidic recently. It has been determined that human activity is responsible for this rise in acidity. Acid rain, utility use of precipitators, sulphur scrubbers, tall stacks, petroleum consumption, and fossil fuel combustion techniques are some anthropogenic factors that could be causing this acidity in lakes. The difference between normal and anthropogenic acidified lakes can be identified based on the colour of the water, an abundance of aquatic life, buffering capability, and the concentration of dissolved organic carbon. This article will explain to you the difference between normal and anthropogenic acidified lakes which will be helpful in preparing the Environment Syllabus for the UPSC Civil Service exam.

Acidification in Lakes

• The prevalence of acids and the relative lack of alkaline bases both contribute to acidity.
• Also, when the water itself and the soil around it are unable to neutralize the acid rain, lakes and streams turn acidic (have a lower pH value).
• The diversity and abundance of fish and other aquatic life that inhabit lakes and streams declines as these waters grow more acidic.
• Freshwater's acidity varies naturally, but most lakes and rivers have a pH between 6 and 9.
• The labels "acidic" and "acidified" are typically reserved for freshwater systems with alkalinity of less than zero, and such systems usually have a pH of less than 5.
• Acidic lakes are typically found in regions with granitic or siliceous bedrock, inadequately buffered, calcium-poor, or thin soils, or regions with pronounced acidic precipitation.

Difference Between Normal and Anthropogenic Acidified Lakes

Solutions for Neutralization of Acidic Lakes

• Reduction of Pollutant Emission: The best long-term solution to the acid rain issue remains to reduce pollutant emissions.
• Additional Mitigation: While waiting for these changes to happen, it is occasionally necessary to rely on band-aid fixes. One of these additional mitigating strategies is liming.
• Liming: Liming is the process of adding a substance to a lake that can balance the acidity of the water.
• The most popular product used in liming is probably finally crushed limestone.
• Crushed limestone liming ensures a gradual rise in water pH to one suitable for aquatic species.
• Other Additives: Lime, hydrated lime, caustic soda, and other items are among those that can be used.
• Repeated Application: Liming is simply a temporary fix; it must be repeated on a regular basis to keep the pH within acceptable limits throughout time.

Conclusion

Scientists believe that the acidity of surface water is reversible. The results of using emission controls demonstrate that reducing emissions did really improve the quality of nearby lakes' surface water. Even though there are indications of improvement for other water quality measures, the pH of the more colored acidic lakes did not change significantly during this time. The prolonged recovery of these colored lakes can be attributed to a number of things, including the presence of chemical components such as organic acids that prolong the healing process and the acidic deposition that is still too high. Keywords: Normal Lake, Anthropogenic Acidified Lake, Acidified Lake, Difference between normal and anthropogenic acidified lakes, Lake Acidification, Neutralization of Acidic Lakes, acid rain, benthic invertebrates, breakdown rate, leaf litter, Taxonomic Richness

FAQs

MCQs

1. What is the primary cause of anthropogenic acidification in lakes?

A) Natural geological processes

B) Increased rainfall

C) Industrial emissions and acid rain

D) Increased temperature

2. Which of the following is a major environmental consequence of lake acidification?

A) Increased biodiversity

B) Decreased fish population

C) Enhanced aquatic plant growth

D) Improved water quality

3. What is the typical pH range of a normal lake?

A) 3.0 - 4.5

B) 5.0 - 6.0

C) 6.5 - 8.5

D) 9.0 - 10.0

4. Which of the following is a common method to reduce the acidity of a lake?

A) Fertilization

B) Liming

C) Introduction of new species

D) Water filtration

5. How does acidification affect the nutrient cycling in lakes?

A) Enhances nutrient availability

B) Disrupts nutrient cycling

C) Increases oxygen levels

D) Accelerates plant growth

GS Mains Questions and Model Answers

Q1: Analyze the impact of anthropogenic acidification on freshwater ecosystems.

Answer: Anthropogenic acidification, primarily caused by industrial pollution leading to acid rain, has severe impacts on freshwater ecosystems. Acidification decreases the pH of lakes, making them more acidic. This disrupts aquatic biodiversity, harms fish populations, and impairs the growth of aquatic plants. Toxic metals like aluminum are leached from the soil into the water, which further harms aquatic organisms. The overall health of the ecosystem declines, reducing the ability of the ecosystem to provide vital services like water filtration and habitat for species. Restoration measures such as liming are often required to restore balance in acidified lakes.

Q2: What measures can be adopted to prevent the acidification of lakes?

Answer: Preventing lake acidification requires a multi-faceted approach. Reducing industrial emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) is crucial, as these gases are the primary contributors to acid rain. Switching to cleaner energy sources, enforcing stricter environmental regulations on industrial emissions, and promoting sustainable agricultural practices can mitigate the problem. Additionally, monitoring water bodies and applying neutralizing agents like lime to acidified lakes can help restore the pH balance. Long-term solutions must focus on reducing the root causes of air pollution and fostering environmental conservation efforts.

Q3: Discuss the ecological consequences of acid rain on freshwater habitats.

Answer: Acid rain, a major contributor to lake acidification, leads to a host of ecological consequences for freshwater habitats. As acid rain lowers the pH of water, it disrupts the reproductive cycles of aquatic species, particularly fish, and makes the water less hospitable for a variety of organisms. The leaching of toxic metals like aluminum from the soil harms fish gills and reduces the availability of essential nutrients. Acidification also affects aquatic plants, reducing oxygen levels and altering food webs. As a result, biodiversity suffers, and the ecological integrity of the lake is severely compromised, requiring restoration efforts to recover the ecosystem.

Previous Year Questions on  Difference between normal and anthropogenic acidified lakes

1. UPSC CSE Prelims 2019:

Question: Which of the following is most likely to be affected by acid rain?

Answer: Acid rain primarily affects freshwater ecosystems, especially lakes and rivers, by lowering the pH and disrupting aquatic life. It also damages plant life and soils, impacting agriculture. However, the most immediate impact is on aquatic organisms like fish and amphibians.

2. UPSC CSE Mains 2020:

Question: Discuss the causes and effects of lake acidification. What steps can be taken to mitigate its effects?

Answer: Lake acidification is caused by pollutants like sulfur dioxide and nitrogen oxides, which form acid rain. The effects are detrimental to aquatic biodiversity, as the lowered pH disrupts fish reproduction, harms plant life, and leaches toxic metals into the water. Mitigation strategies include reducing emissions, liming acidified lakes, and promoting environmental conservation.