Diving into the Depths: Unveiling the Threat of Ocean Acidification

November 4, 2021 in environment, Sustainability

Article summary and Key takeaways: Ocean acidification is a process in which carbon dioxide from the atmosphere is absorbed by seawater, resulting in a decrease in the ocean’s pH level. This has significant consequences for marine life, ecosystems, and coastal communities. The primary cause of ocean acidification is the absorption of carbon dioxide by the ocean, largely due to human activities such as burning fossil fuels. Other factors, such as nutrient pollution and volcanic eruptions, also contribute. The increased acidity affects coral reefs, shell-forming organisms, and disrupts marine food webs. It also impacts entire ecosystems, leading to shifts in species dominance and composition. Fisheries, aquaculture, and coastal communities are at risk. Understanding the chemistry of ocean acidification is crucial, as it involves a decrease in pH levels and the availability of carbonate ions, which are essential for shell and skeleton formation. International efforts and agreements, such as the United Nations Sustainable Development Goal 14 and the Paris Agreement, recognize the need to address ocean acidification. Mitigation strategies involve reducing carbon dioxide emissions and enhancing natural carbon sinks. Adaptation strategies focus on developing resilient marine ecosystems and sustainable fisheries management. Public awareness and education are vital in addressing the issue. Continued research and monitoring are necessary to track the progression of ocean acidification and inform decision-making processes.

What is Ocean Acidification?

Ocean acidification is a phenomenon that occurs when carbon dioxide (CO2) from the atmosphere is absorbed by seawater, resulting in a decrease in the ocean’s pH level. This decrease in pH makes the water more acidic, hence the term “ocean acidification.” Understanding this process is of utmost importance as it has far-reaching consequences for marine life, ecosystems, and even coastal communities.

Causes of Ocean Acidification

The primary cause of ocean acidification is the absorption of carbon dioxide by the ocean. When CO2 from the atmosphere dissolves in seawater, it reacts with water to form carbonic acid. This acidification process is exacerbated by the excessive release of CO2 into the atmosphere through human activities such as burning fossil fuels, deforestation, and industrial processes.

Other factors also play a role in ocean acidification. For instance, nutrient pollution from agricultural runoff and wastewater discharge can lead to increased algal blooms, which consume oxygen and release CO2 as they decompose. Additionally, natural geological processes and volcanic eruptions can release significant amounts of CO2 into the atmosphere and subsequently into the ocean.

Effects of Ocean Acidification

Impact on Marine Life

The chemistry behind ocean acidification has significant implications for marine life. When CO2 dissolves in seawater, it forms carbonic acid, which increases the concentration of hydrogen ions (H+) in the water. This increase in acidity can have detrimental effects on various marine organisms.

Coral reefs, for example, are particularly vulnerable to ocean acidification. The increased acidity inhibits the ability of corals to build and maintain their calcium carbonate skeletons, resulting in coral bleaching and eventual death. This has devastating consequences for the diverse ecosystems that depend on coral reefs for habitat and food sources.

Shell-forming organisms such as oysters, clams, and certain planktonic species are also at risk. The decreased pH levels make it more difficult for these organisms to form and maintain their shells and exoskeletons, hindering their growth and survival. This disruption of shell formation can have cascading effects throughout the food chain.

Furthermore, ocean acidification can disrupt marine food webs. Many species rely on calcifying organisms for their food sources, and their decline can lead to a decrease in overall biodiversity and abundance in marine ecosystems.

Impact on Ecosystems

The effects of ocean acidification extend beyond individual species, impacting entire ecosystems. Changes in biodiversity are expected as certain species are more resilient to acidification than others. This can result in shifts in species dominance and composition, potentially leading to a loss of biodiversity and ecological stability.

Fisheries and aquaculture are also at risk. Acidification has the potential to affect fish populations, both directly by impairing their ability to navigate, reproduce, and grow, and indirectly by disrupting their food sources. This can have severe economic and food security implications for communities that rely on fishing and aquaculture as a primary source of income and sustenance.

Coastal communities may also face consequences as ocean acidification affects the health of coastal ecosystems. These ecosystems provide crucial services such as shoreline protection, nutrient cycling, and carbon sequestration. The decline of these services can lead to increased vulnerability to storms, erosion, and loss of vital habitats.

Understanding the Chemistry of Ocean Acidification

To grasp the complexity of ocean acidification, it is essential to understand the underlying chemistry. The pH scale is used to measure the acidity of a substance, with lower values indicating higher acidity. A pH of 7 is considered neutral, while values below 7 are acidic.

Ocean acidification refers to the decrease in pH levels of seawater. The current average surface pH of the ocean is around 8.1, which is slightly alkaline. However, due to the influx of CO2, it is estimated that the pH of the ocean has dropped by 0.1 units since the beginning of the Industrial Revolution.

Chemical reactions occur when carbon dioxide dissolves in seawater, leading to the release of hydrogen ions (H+). These hydrogen ions combine with carbonate ions (CO3^2-) already present in the water, reducing their availability. Since many marine organisms rely on carbonate ions to form their shells and skeletons, a decrease in their concentration can hinder their growth and survival.

Efforts to measure and monitor ocean acidification involve the use of sensors and buoys to collect data on pH levels, carbonate chemistry, and other relevant parameters. These monitoring initiatives help scientists track changes over time and provide valuable insights into the progression of ocean acidification.

Addressing the Problem of Ocean Acidification

International Efforts and Agreements

The issue of ocean acidification has gained global attention, leading to several international efforts and agreements aimed at addressing the problem. The United Nations Sustainable Development Goal 14 focuses specifically on conserving and sustainably using the oceans, including efforts to mitigate and adapt to ocean acidification.

The Paris Agreement, a landmark international climate agreement, also recognizes the need to reduce greenhouse gas emissions to limit the impacts of climate change, including ocean acidification.

Mitigation Strategies

Reducing carbon dioxide emissions is crucial in mitigating ocean acidification. This involves transitioning to cleaner, renewable energy sources, improving energy efficiency, and implementing carbon capture and storage technologies to capture and store CO2 emissions from industrial processes.

Enhancing natural carbon sinks, such as forests and coastal wetlands, can also help mitigate the effects of ocean acidification. These ecosystems absorb and store carbon dioxide, preventing it from entering the atmosphere and subsequently the ocean.

Adaptation Strategies

Adapting to the impacts of ocean acidification requires the development of resilient marine ecosystems. This can be achieved through the protection and restoration of critical habitats, such as coral reefs and seagrass beds, as well as the creation of marine protected areas that allow ecosystems to recover and rebuild their natural resilience.

Sustainable fisheries management is also crucial in adapting to ocean acidification. Implementing measures such as catch limits, gear restrictions, and marine spatial planning can help ensure the long-term viability of fisheries and minimize the impacts of acidification on fish populations.

Public awareness and education play a vital role in addressing ocean acidification. By raising awareness about the issue and its potential consequences, individuals can make informed choices and take actions to reduce their carbon footprint and support sustainable practices.


Ocean acidification is a complex and pressing issue that poses significant risks to marine life, ecosystems, and coastal communities. Understanding the chemistry behind this process and its far-reaching effects is crucial in developing effective strategies to mitigate and adapt to ocean acidification.

International efforts, as well as individual actions, are needed to reduce carbon dioxide emissions, enhance natural carbon sinks, and promote sustainable practices. Continued research and monitoring are essential to track the progression of ocean acidification and inform decision-making processes.

By taking action now, we can minimize the impacts of ocean acidification and protect the invaluable resources provided by the world’s oceans for future generations.

Question: What is ocean acidification in simple terms?
Answer: Ocean acidification is the process of the ocean becoming more acidic due to the absorption of carbon dioxide from the atmosphere.

Question: What is ocean acidification? Why is it bad?
Answer: Ocean acidification is the increase in acidity of the ocean, which is harmful because it can negatively impact marine life and ecosystems.

Question: What is ocean acidification in real life?
Answer: Ocean acidification is a real phenomenon that is occurring due to human activities, such as burning fossil fuels, and it is causing significant changes in the chemistry of the ocean.

Question: What is ocean acidification answer key?
Answer: An answer key for ocean acidification would provide the correct responses to questions or problems related to the topic, helping to assess understanding or knowledge.


About the author 

Jordan Miller

Hi there, I'm Jordan! I graduated from UC Berkeley with a major in Environmental Policy, but my real education has been in the field, turning theory into practice. My days are filled with implementing sustainable solutions and teaching communities how to embrace an eco-friendly lifestyle. I believe small changes can make a big impact, and I'm here to guide you through every step of going green.