Ocean acidification is a growing global issue. A third to half of the CO2 emitted by human activities is absorbed into the oceans, where it has a direct, chemical effect on sea water, which we call ocean acidification. With such a rapid change in ocean chemistry, marine life, which evolved over millions of years in an ocean with a generally stable pH, does not have much time to adapt. In fact, some animals' shells are already dissolving in the more acidic seawater, and this is just one way that acidification may affect ocean life. In this article, we will discuss the Effect of Ocean Acidification which will be helpful for UPSC exam preparation.

Effects of Ocean Acidification

• The oceans are a significant CO2 reservoir, absorbing a significant amount of it (one-third) produced by anthropogenic activities and effectively mitigating climate change.
• Carbon dioxide is being absorbed from the atmosphere at a rate that exceeds the oceans' natural buffering capacity.
• In some organisms, increasing acidity reduces metabolic rates and immune responses.
• Carbonic acid, bicarbonate, and carbonate ions are formed when sea water absorbs CO2.
• However, increased CO2 levels in the atmosphere cause a decrease in pH, an increase in the concentration of carbonic acid and bicarbonate ions, and a decrease in the concentration of carbonate ions.
• The reduced availability of carbonate ions makes it more difficult for marine calcifying organisms like coral (calcareous corals) and some plankton (calcareous plankton) to form biogenic calcium carbonate.
• Commercial fisheries are under threat as a result of acidification, which harms calcifying organisms, which form the foundation of Arctic food webs.
• Coral bleaching is exacerbated by rising acidity because corals are extremely sensitive to changes in water composition.

Effect of Ocean Acidification on Cloud Formation

• The ocean emits the majority of the sulfur in the atmosphere, often in the form of dimethyl sulfide (DMS) produced by phytoplankton.
• Some dimethyl sulfide (DMS) produced by phytoplankton enters the atmosphere and combines with oxygen to form sulphuric acid, which clumps into aerosols, or microscopic airborne particles.
• Aerosols cause clouds to form, which help to cool the Earth by reflecting sunlight.
• However, phytoplankton produces less DMS in acidified ocean water.
• This sulphur reduction may result in less cloud formation, raising global temperatures.

Effect of Ocean Acidification on Marine Organisms and Ecosystem

• Ocean acidification reduces the amount of carbonate, a key building block in seawater.
• This makes it more difficult for marine organisms, such as coral and some plankton, to form shells and skeletons, and existing shells may begin to dissolve.
• The pH of seawater is highly variable, and a single organism can cope with fluctuations of different pH levels over its lifetime.
• The issue with ocean acidification is the long-term nature of the change, as the risk comes from lifetime exposure to lower pH levels. The rate of acidification will affect the ability of calcifying organisms to adapt.
• The effects of ocean acidification are not the same for all species. Higher CO2 concentrations in the ocean may benefit some algae and seagrass by increasing photosynthetic and growth rates.
• A more acidic environment, on the other hand, will harm other marine species such as mollusks, corals, and some types of plankton. These animals' shells and skeletons may become less dense or strong.
• This may make coral reefs more vulnerable to storm damage and slow their recovery rate.
• In response to ocean acidification, marine organisms may experience changes in growth, development, abundance, and survival.
• Most species appear to be more vulnerable in their early stages of development. Juvenile fish, for example, may have difficulty finding suitable habitat to live in.
• Regardless of whether the responses within and between marine groups are positive or negative, research indicates that ocean acidification will be a driver of significant changes in ocean ecosystems this century.
• These changes may be exacerbated by the interaction with other emerging climate-related hazards, such as the decrease in ocean oxygen levels, known as ocean deoxygenation, which is already affecting marine life in some areas.

Effect of Ocean Acidification on Human Society

Food

• Ocean acidification has the potential to impact food security.
• The global annual costs of mollusk loss due to ocean acidification could exceed $100 by 2100.
• When fish die, humans who rely on them for food and a living suffer from socioeconomic problems.
• This process also contributes to acidic waters, which harm agricultural production even more.
• Soil acidity rises as a result of acidic water. This makes the cultivation and production of certain crops impossible.

Human Health

• When the acidity of the ocean water rises, the consumers or users of that water are put in danger.
• Cancers can be easily transmitted to humans when they consume fish tainted with higher sulphur concentrations.

Coastal Protection

• Coral reefs, which protect coastlines from storm surges and cyclones, will be harmed.
• The coastal estuaries and waterways are being affected by ocean acidification.

Tourism

• This industry could be severely impacted by the effects of ocean acidification on marine ecosystems.
• Acidification could harm the Arctic tourism economy and indigenous peoples' way of life.

Carbon Storage and Climate Regulation

• As the ocean acidifies, its ability to absorb CO2 decreases.
• More acidic oceans are less effective at mitigating climate change.

Ocean Acidification in the Indian Ocean

• The Arabian Sea's surface waters are becoming acidic as a result of excess carbon dioxide in the atmosphere.
• Pollutants from the Indo-Gangetic plains mix with seawater in the northern Bay of Bengal, causing ocean acidification.
• During the winter, air blowing from land to sea carries all pollutants with it and deposits them in the ocean.
• A study found that the presence of marine phytoplankton in the western Indian Ocean is rapidly declining.
• Given the levels of ocean warming, a report warns that the Indian Ocean may be reduced to an ecological desert.
• The Indian Ocean, which is one of the most pristine and fertile regions on the planet, will be devastated by ocean acidification in the Arabian Sea and Bay of Bengal.

Conclusion

Ocean acidification is the worldwide decrease in the pH of seawater caused by the oceans' absorption of large amounts of carbon dioxide (CO2). The entire world's oceans, including coastal estuaries and waterways, are being affected by ocean acidification. Many economies rely on fish and shellfish, and people all over the world rely on seafood as their primary source of protein. The ultimate solution to ocean acidification is to reduce global greenhouse gas emissions.

FAQs

MCQs

1. What is the primary cause of ocean acidification?

A) Increased ocean temperatures
B) Overfishing
C) Increased levels of CO2 in the atmosphere
D) Excessive plastic pollution

2. Which marine organisms are most affected by ocean acidification?

A) Fish
B) Marine mammals
C) Corals, shellfish, and plankton
D) Sea turtles

3. How does ocean acidification impact human industries?

A) It improves fishing yields
B) It decreases food security by affecting marine species
C) It boosts the marine tourism industry
D) It has no significant impact

4. Which of the following is a potential solution to mitigate ocean acidification?

A) Increased industrial fishing
B) Reducing CO2 emissions through renewable energy
C) Large-scale desalination projects
D) Expanding the use of plastic in oceans

5. Which ecosystem can help mitigate the impacts of ocean acidification?

A) Coral reefs
B) Mangroves and seagrasses
C) Deep-sea vents
D) Ice sheets

GS Mains Questions and Model Answers

Q1: Analyze the causes and effects of ocean acidification. How does it impact marine biodiversity?

Answer: Ocean acidification is primarily caused by the absorption of excess carbon dioxide (CO2) from the atmosphere into the oceans. This leads to a decrease in the pH of the water, making it more acidic. The effects of ocean acidification are particularly damaging to marine organisms that rely on calcium carbonate to form their shells and skeletons, such as corals, mollusks, and plankton. These species are essential to marine food webs, and their decline can disrupt ecosystems, threaten biodiversity, and affect industries like fishing. Additionally, ocean acidification can lead to the loss of coral reefs, which serve as important habitats for marine life and protect coastal communities from storm surges.

Q2: What are the socio-economic implications of ocean acidification on human communities?

Answer: Ocean acidification has significant socio-economic implications, particularly for coastal communities that depend on fishing and marine resources for their livelihoods. As the acidity of the ocean increases, it threatens the survival of marine species, which can result in reduced fish stocks and lower income for fishermen. This can also affect food security, as many communities rely on seafood as a primary source of protein. Additionally, the decline in coral reefs and other marine ecosystems could impact tourism, another important economic sector in coastal regions.

Q3: How can international cooperation help address the problem of ocean acidification?

Answer: Ocean acidification is a global problem that requires international cooperation to address effectively. Collaborative efforts can help reduce global CO2 emissions, which are the primary driver of ocean acidification. Countries can work together through international agreements like the Paris Agreement to commit to reducing emissions. Moreover, sharing research and technologies related to ocean monitoring, carbon capture, and restoration of marine ecosystems can provide solutions to mitigate acidification. Furthermore, the establishment of marine protected areas and the conservation of critical ecosystems such as mangroves and seagrasses can buffer against the impacts of ocean acidification.

Previous Year Questions on Ocean Acidification

1. UPSC CSE Prelims 2021:

Question: What is the main cause of ocean acidification?

A) Increase in ocean temperatures
B) Increased CO2 absorption by oceans
C) Excessive fishing activities
D) High levels of mercury in oceans

Answer: (B)

Explanation: Ocean acidification is mainly caused by the increased absorption of CO2 from the atmosphere into the oceans, which reacts with seawater to form carbonic acid.

2. UPSC CSE Mains 2019 (GS Paper 3):

Question: "Examine the environmental and economic challenges posed by ocean acidification. How can they be mitigated?"

Answer: Ocean acidification presents both environmental and economic challenges. Environmentally, it threatens marine biodiversity, especially species that rely on calcium carbonate. Economically, it impacts fishing industries and coastal communities. Mitigation strategies include reducing CO2 emissions, protecting marine ecosystems, and promoting sustainable practices such as responsible fishing and restoration of coral reefs and seagrasses.