Ocean Acidification | Causes, Effects, and Solutions

The ocean absorbs about one-third of the carbon dioxide released from human activities. This causes its pH level to drop, making it more acidic. Ocean acidification threatens entire marine food webs and ecosystems. This impacts biodiversity and fisheries that people rely on. If carbon dioxide emissions continue unchecked, ocean acidity could increase by 150-200 percent by 2100. At that point, the ocean would be corrosive enough to dissolve shells throughout its depths. Rapid ocean acidification is a major global threat with severe ecological and economic consequences if not addressed promptly.

ocean acidification

Interesting Facts About Ocean Acidification

  • 🌊 pH Shift. Since the Industrial Revolution, the ocean’s surface pH has dropped by 0.1 units, representing a 30% increase in acidity due to increased CO2 absorption.
  • 🐚 Shell Dissolution. Many marine organisms, such as mollusks and coral, struggle to maintain their calcium carbonate shells and skeletons in more acidic waters, making them more vulnerable to dissolution.
  • 🌍 Widespread Impact. Ocean acidification affects all oceanic regions, but polar and coastal waters are experiencing the most significant changes due to their specific chemical compositions and colder temperatures.
  • 🐠 Fish Behavior. Increased acidity can impair fish behavior and sensory functions, affecting their ability to detect predators, find food, and navigate.
  • 🧬 Genetic Adaptation. Some species, like certain sea urchins and fish, are showing signs of genetic adaptation to more acidic conditions, though this process is slow and not a universal solution.
  • 🪸 Coral Reefs. Ocean acidification exacerbates coral bleaching, where corals expel the symbiotic algae living in their tissues, causing them to turn white and making it harder for reefs to recover from other stressors.
What is Ocean Acidification?

Understanding Ocean Acidification

Ocean acidification is a serious problem that affects the sea and the people living by it. It happens when the ocean takes in too much carbon dioxide from the air. This makes the water more acidic.

What is Ocean Acidification?

Seawater absorbs CO2 from the air, making it more acidic with lower pH levels. The seawater’s average pH has dropped from 8.2 to 8.1 in the last 200 years, meaning it’s about 30% more acidic.

The Role of Carbon Dioxide Absorption

The ocean is a key player in reducing the amount of CO2 in the air, eating up a lot of what we produce. But as humans release more and more CO2, the ocean is having a hard time keeping up. A 2014 global study found that in many areas, the pH of the ocean was dropping and CO2 levels were rising.

Impact on Seawater Chemistry

More CO2 in the ocean changes its chemistry, affecting life in the sea. It makes the water less suitable for animals that need carbonate to build shells, like oysters and corals. Places like the Arctic and Antarctic seas are seeing their carbonate levels drop, making it tough for shell-building creatures to survive. Also, the changes can impact how some fish sense danger, throwing off the balance of life in the sea.

Ocean Acidification and its Impact on Marine Life

marine life

Ocean acidification is hurting many sea creatures, especially those that build hard parts. These include oysters and corals. They use calcium and carbonate from the water. For example, pteropod shells dissolved after 45 days in future seawater conditions. This was a test for the year 2100’s expected water chemistry.

Severe shell damage in the Southern Ocean hints at a big problem. This ocean is around Antarctica.

Effects on Shell-Building Organisms

Ocean acidification has already made seawater 30% more acidic. This affects shell-making creatures like mussels. They’re predicted to grow 25% less shell by 2100. Oysters could grow 10% less shell.

Surprisingly, some shellfish like lobsters, crabs, and shrimp are building stronger shells. But, a study warns that by 2080, ocean acid levels will erode coral reefs faster than they can rebuild.

Impacts on Fish and Seaweeds

Ocean acidification messes with more than just shell-makers. It can change the behavior of some fish. For example, making it harder for them to spot predators. This impacts the whole ocean food chain.

Some fish and plants will be at a disadvantage. Yet, algae and seagrasses could thrive in the more acidic ocean.

The pH Scale and Ocean Acidification

What is Ocean Acidification?

The pH scale ranges from 0 to 14. Seven is neutral while higher values are basic and lower are acidic. It shows how many hydrogen ions are in a liquid. More ions make it more acidic with a lower pH.

Carbon dioxide in the air mixes with seawater. This creates carbonic acid, which breaks into hydrogen and bicarbonate ions. With more carbon dioxide in our air, the ocean gets more of it. This makes the ocean’s pH drop, turning it more acidic.

The ocean’s pH is currently 8.1 but is getting lower due to absorbing more CO2. Since the industrial era, the pH has dropped from 8.2 to 8.1. Scientists expect a further drop of 0.3 to 0.4 by 2100. A 0.1 drop may seem small. Yet, because of the logarithmic scale, it’s a 120% increase in acidity. This could drop the pH to 7.8 or 7.7 within this century. Since the Industrial Revolution, the surface ocean’s pH has fallen by 0.1 units.

Some forecasts show the ocean’s acidity could be 150% more by 2100. If this happens, ocean pH levels will be as low as they were over 20 million years ago. This environment was last seen 14-17 million years ago. Earth was much warmer then, facing a significant extinction period.

Global Rise in Atmospheric Carbon Dioxide Levels

atmospheric carbon dioxide

Increasing CO2 Emissions and Climate Change

A recent report shows a big problem – global CO2 emissions are staying high. They hit a huge number in 2023, reaching 36.6 billion tons. This is a lot more than what we saw in the 1960s, around 11 billion tons. In 2023, the amount of CO2 in the air was measured at 419.3 parts per million (ppm), with a 2.8 ppm increase from the year before. Human activity is mainly responsible for this big rise in CO2, which directly links to the climate change crisis that continues.

Impacts on Natural Carbon Sinks

The ocean is a hero because it takes in about 30% of the CO2 we emit. Additionally, forests and other natural places also soak up about half of the world’s emitted CO2 each year. This happened a lot during the 2011-2020 decade. However, the rate of CO2 going into the air has gotten a lot faster. In the 2010s, this rate was at 2.4 ppm every year, which is three times more than the past half-century. This fast absorption of CO2 is making the ocean’s pH level drop. This process is called ocean acidification.

Looking ahead, if we keep going like we are, the water in our seas could become very acidic. The last time it was as acidic as it could become, the Earth was in a very tough spot. It was much warmer than today and a massive extinction event was happening. This paints a clear picture: we need to act now to save our planet and our oceans for the future.

Implications for Coastal Communities and Industries

Ocean acidification is troubling the seas, affecting coastal areas and their waterways. Billions globally eat ocean foods for protein. Many jobs and economies rely on sea life, both in the U.S. and worldwide.

coastal communities

Threats to Fisheries and Aquaculture

Industries like fishing and farming face big risks from ocean acidification, especially those growing oysters and clams. These types of seafood are very easily affected. By the year 2100, high CO2 emissions could cause us to lose over US$100 billion annually. Oyster farming was hit earliest by ocean acidification.

Economic Consequences

Risks to coastal industries could mean major economic problems for nearby communities. The tourism linked to oceans made over USD 1.6 trillion worldwide in 2017. In the U.S., over 80% of tourism earnings come from coastal activities. It’s also the biggest part of worldwide tourism. The Great Barrier Reef in Australia is a notable example. It brings in over A$5.4 billion yearly and welcomes about 1.9 million visitors. Communities and trades that rely on healthy reefs for tourism or fishing are in danger due to ocean acidification.

Marine ecosystems like coral reefs, worth US$9 billion each year, protect coasts from storms. Economic harm from less fishing and farming could hit communities hard. To tackle ocean acidification, we must cut down on CO2 from fossil fuels.

Ocean acidification impact on mollusc industriesPotential global annual costs of mollusc loss could exceed US$100 billion by 2100 under high CO2 emissions scenarios
Coral reef contribution to global tourism revenuesCoral reefs contribute USD 11.5 billion annually to global tourism revenues
Great Barrier Reef economic impactThe Great Barrier Reef Marine Park in Australia generates more than A$5.4 billion to the economy annually from tourism and attracts about 1.9 million visits per year
Portion of U.S. tourism revenues from coastal areasCoastal tourism accounts for over 80% of tourism revenues in the United States

Monitoring and Researching Ocean Acidification

ocean acidification monitoring

Efforts to keep track of ocean acidification are just starting. We can’t yet say for sure how it will affect sea life and ecosystems. NOAA’s Ocean Acidification Program aims to connect scientists with those who make decisions. They want to see how ocean changes affect important areas like fishing and coral reefs. As ocean acidification is becoming a bigger issue, people agree we need to study it more. This will help make better decisions and take the right actions.

NOAA’s Ocean Acidification Program

The NOAA Ocean Acidification Program supports top-notch research, monitoring, and education efforts. These projects look into ocean acidification and its effects. The Program funds important work, like a recent project receiving $1,451,575 for three years. This project is a collaboration between NOAA and the National Oceanographic Partnership Program. In March 2023, the Biden-Harris Administration presented the Ocean Climate Action Plan. It focused on removing carbon from the sea as a key step in ocean climate efforts.

Studying Ecosystem Impacts

There are 19 OAP-supported buoys watching over ocean acidification in various waters. These buoys use special sensors to check carbon dioxide levels every three hours in the open sea and around coral reefs. Ships, which help gather data, visit remote places to study ocean acidification.

Work includes checking the water’s chemistry in coral reefs all over the Atlantic, Caribbean, and Pacific. By studying the ocean, scientists can make predictions. This tells us how ocean acidification might impact different sea creatures.

Researchers are also working on predicting acidity changes in places like the West Coast. For the North Pacific, they’ve developed a system that gives seasonal acidification forecasts. This helps in making the best choices for handling ocean acidification. Coastal Acidification Networks try to find the worst acidified spots in the sea. They use various tools to keep an eye on how coral reefs and other marine life are affected.

Mitigating Ocean Acidification

Ocean acidification comes from carbon pollution, mostly from burning fossil fuels. We need to switch to clean energy globally to fight this. That means making laws to cut power plant pollution and using better fuel in cars. It’s important for leaders to also work on conservation. By protecting places like forests and wetlands, we help keep carbon out of the air.

ocean acidification mitigation

Transitioning to Clean Energy

Using clean energy like solar power and wind power is vital. Policymakers should make rules that encourage using less polluting energy sources. This will help lower the carbon in the air and fight ocean acidification.

Conservation Efforts and Carbon Sinks

Natural places like carbon sinks do a big job in storing carbon. This includes places like wetlands and seagrass beds. They take carbon out of the air and put it in the ground. Protecting these areas helps fight ocean acidification.

Adaptive Strategies for Vulnerable Industries

Some industries, like oyster farms, are at risk from ocean acidification. They can protect themselves by using special oysters and growing seaweed. This lets them survive in water that’s becoming more acidic.

Real-Time Data and Educational Resources

Ocean acidification harms the sea and businesses like oyster farms. It fits well with lessons on food chains, impacts of climate change, and chemistry. Students can look at updated info on CO2 in seawater and air to get it.

In the U.S. West Coast, young Dungeness crabs are feeling ocean acidification’s effects. This links to lessons on food chains, ecosystems, and the ocean’s health. Using fresh data on CO2, teachers can make learning engaging.

In high school, kids learn to be ocean scientists by studying carbon’s impact on the sea. They test how CO2 affects water, algal growth, and more. Teachers get a webinar to guide them through using live data in lessons.

There are also tests that match the Next Generation Science Standards to check learning. Data from the Hawaii Ocean Time-series project has plenty of info for this. Teachers can find what they need for analysis even after removing some info.

Time PeriodMean Seawater pHMean Seawater CO2 Partial Pressure (μatm)

Data was sorted into five-year chunks for better study. It was all changed to a standard date look for easy comparing. Key stats, like seawater pH, help us understand ocean acidification.

Ocean Acidification and the Dungeness Crab

The Pacific Northwest coast is facing serious issues due to ocean acidification. This affects young Dungeness crabs. They are important for the economy and people in this area.

Dungeness crab

These crabs live along the U.S. West Coast and are very valuable. They are known to be sensitive to ocean acidification. This means their development and survival are at risk.

A study in Washington state shows that acidity is getting worse. This might reduce the number of Dungeness crabs caught and their value.

In Alaska, other crab species are also affected. Juvenile crabs have trouble growing and surviving in acidic waters. This can affect Alaska’s crab industry greatly.

This study underlines the serious impact of ocean acidification. It’s crucial to find ways to fight it. The future of seafood and coastal communities depends on it.

The Urgency of Addressing Ocean Acidification

Our oceans are changing quickly, and the future is uncertain. We need to take action. This includes making climate action plans that increase investments in watching, predicting, and stopping this change. By cutting down on harmful emissions, we could save 30% of coral reefs from disappearing.

Many jobs and important parts of our economy are at risk from ocean acidification. So, we’re working to protect these areas and make sure our marine life can survive.

Ocean acidification is happening faster than we thought. Scientists, managers, and leaders all say we need to act now. Taking fast action on climate change can prevent big losses in the fish we catch. This will keep our fisheries healthy. The main way to fight ocean acidification is to reduce the use of fossil fuels. This change can stop more harm to our oceans.

The risks to our economy from ocean acidification are high, especially for fisheries. For example, shellfish can’t build their shells as well, which affects us and the marine food web. This also means less food in the sea, hurting industries and tourism worldwide, like in the Pacific Northwest of the United States.

FAQs on Ocean Acidification

What is ocean acidification?

Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.

What causes ocean acidification?

Ocean acidification is primarily caused by the absorption of excess atmospheric CO2, which reacts with seawater to form carbonic acid.

How does ocean acidification affect marine life?

Ocean acidification affects marine life by reducing the availability of carbonate ions, which are crucial for organisms like corals, shellfish, and some plankton to build their skeletons and shells.

What are the economic impacts of ocean acidification?

The economic impacts include threats to fisheries, aquaculture, and tourism industries, as the decline in marine biodiversity and health affects these sectors.

Can ocean acidification affect human health?

Yes, ocean acidification can affect human health indirectly by reducing the availability of seafood, a vital source of protein, and by impacting marine ecosystems that support coastal protection and water quality.

How is ocean acidification measured?

Ocean acidification is measured by monitoring changes in the pH, carbonate ion concentration, and partial pressure of CO2 in seawater.

What are the potential long-term effects of ocean acidification?

Long-term effects include severe disruptions to marine ecosystems, loss of biodiversity, and alteration of food webs, which could have cascading effects on global food security and economies.

Is there any way to mitigate ocean acidification?

Mitigation strategies include reducing CO2 emissions, protecting and restoring marine ecosystems, and exploring geoengineering solutions to enhance the ocean’s natural ability to absorb CO2.

What role do phytoplankton play in ocean acidification?

Phytoplankton, through photosynthesis, absorb CO2 and produce oxygen. However, changes in ocean chemistry due to acidification can affect their growth and the overall carbon cycle.

How can individuals help combat ocean acidification?

Individuals can help by reducing their carbon footprint, supporting policies aimed at reducing CO2 emissions, and advocating for marine conservation efforts.

References and Sources

Coastal Adapt – Ocean acidification and its effects

Smithsonian – Ocean Acidification

NOAA OAP – Ocean Acidification Program

Oceanography Society – Ocean Acidification Risk to Dungeness Crab