Ocean Acidification: Solutions and Threats

Introduction

Ocean Acidification, the absorption of CO2 into the ocean which raises the water's acidity, will inevitably damage the environment. Many have mistakenly assumed that the ocean is unaffected by climate change, however, they could not be more incorrect. This is because acidity lowers marine species' metabolism and immune responses, as well as erode the shells of vital marine species, such as clams, oysters, urchins, and tetrapods. The awareness of this topic and the implementation of ocean acidification solutions are integral in preventing irreversible changes to our marine life.

Causes and Effects of Ocean Acidification

The lowering of pH in seawater can initially be blamed by the Industrial Revolution. Since this event’s beginning in 1760, studies have shown that the ocean’s pH level has decreased by 0.1 (a raise of acidity in 30 percent). Scientists predict that the ocean’s acidity levels will increase by 150 percent by the end of the century due to continuance of carbon dioxide emissions. While carbon dioxide is absolutely necessary for our ecosystem and plant life, it is beginning to be produced faster than it can be naturally absorbed, and the ocean is starting to take a toll, among other things. This is based on the idea that the ocean absorbs some of the carbon dioxide (the leading cause), nitrogen oxides and sulfur oxide gases emissions from man made sources, such as fuel burning and machinery, are absorbed into the ocean. This is logical, as these emissions and affected by gravity and often runoff in to the ocean. The pH of seawater is lowered when carbonic acid (H2CO3) mixes with water molecules (H20) to form a chemical reaction that result in the increase of acidity. When the H2CO3 and the H20 mix, they break down to form a hydrogen ion (H+) and bicarbonate (HCO3-). This is what lowers the pH of the seawater.

Other research has revealed that continued decrease in the seawater’s pH will begin to effect ocean life in varying manners. Over time, acidity can harm some sea creatures. Sea creatures that use calcium carbonate in their shells are particularly at risk. The diagram above shows the shell of a pteropod, a sea creature about the size of a pea. By 2100, this diagram will be an accurate representation of the time it takes for a pteropods shell to dissolve in the ocean water.

The effects of ocean acidification are true of shellfish, as well. This has been evident through the failure of farming shellfish in aquaculture facilities and natural ecosystems in the West Coast, which accounts for almost 85 percent of its economic gains and over 42,000 jobs, as well as food and cultural identity for local tribes. This is believed to be a result of upwelling (upwelling is the occurrence of water below the surface rising above after the original surface water was blown elsewhere by the wind) that lowers the water’s pH. While a rise in acidity as a result of upwelling is considered natural, studies are suggesting that anthropogenic CO2 could have a part to play in this phenomenon. Indeed, ocean acidification could very well be responsible for this threat to the $100 million a year industry of shellfish farming, but it would be unwise to make this conclusion thus far.

Washington State is particularly affected by ocean acidification due to regional implications, such as costal upwelling. This upwelled water heavy in carbon dioxide, with little pH. This water being upwelled was originally flowing deep under the surface that absorbed CO2 from the atmosphere 30 to 50 years ago. This water is being upwelled back to the top, serving a sort of time capsule from the 1970s. Also, Washington’s waters experience runoff from storms that feed into the upwelled water, removing many sea floor plants and absorbing carbon dioxide. This has varying effects on different places. An example of this could be that billions of oyster larvae were lost in Washington, damaging its farming industry significantly through 2005 and 2009. It can be logically concluded that Washington’s marine life is threatened by ocean acidification.

More areas being affected by ocean acidification through their oceans are Puget Sound and the Strait of Juan de Fuca, with plenty of acidic, upwelled water. Within the Puget sound are estuarine environments, with dissolved oxygen and carbonate saturation that can further reduce pH. Sulfur oxide and nitrogen oxide from urban areas may also lower the pH of the ocean water, but it’s currently too early to make that conclusion. Acidification in the Puget Sound also varies by season, with data collected in the winter showing well distributed acidity, and with layers of different pHs in the water during the summer. Willapa Bay and Totten Inlet are better distributed in pH and of different shape than the other estuaries of Puget Sound like Hood Canal, Dabob Bay, and the Main Basin. Due to the fact that they are smaller, fresh water addition and upwelling has greater effect than normal in its shallowness. Also, photosynthesis has more power on the ocean plants there, as they are closer to the water’s surface, thus absorbing more sunlight. This can result in more carbon dioxide, as there are more plants decomposing.

In addition to runoff and upwelling, rivers and streams that flow into the ocean play a part in ocean acidification. The water from these rivers and streams typically have higher acidity, with pH’s ranging from 6.5 to 8.5. This is a result of added minerals from soil and other organic material that isn’t typically found in the ocean. Waste water from industrial outputs can also runoff into the ocean and lower the pH.

The increase of acidity in the ocean has also had a negative effect on corals. The anthropogenic greenhouse gas emissions has put 33 percent of reef building corals in danger of bleaching. The color of corals comes from symbiotic algae, and the loss of these algae would mean inevitable death of the corals. One fourth of marine fish species live in coral reefs, as well as 500 million humans needing them for subsistence. In 2015, WWF predicted that by 2100 the loss of corals will cost $500 billion a year, as well as the prediction that coral reefs will start to erode faster than they can be rebuilt made by other studies.

The environmental and potential economic impact of ocean acidification has prompted research for further understanding of this dilemma. Experiments have been done in northern Pacific Ocean by hydrography cruises, which has yielded significant data. Over the course of 15 years, pH documentation from 6000 meters below the ocean surface has shown a rise correlated with the atmospheric increase of CO2. Currently, NOAA Ocean Acidification observers are working to expand their outreach. They intend to conduct ship-based observations of ocean acidification along the East and West Coasts of America, as well as the West Coast of Canada, the Southeast Gulf of Mexico, and the coasts of Alaska.

People often have the misconception that the ocean is becoming acid, and will soon be too dangerous to occupy for humans. However, this is quite false. A pH of 7.8 (the predicted acidity level of the ocean water by the next century) is not harmful to humans at all, which is in fact often the acidity level of swimming pools. However, to say that humans’ health won’t be affected by ocean acidification would be premature. We heavily exploit the ocean for food, medicine, transportation, etc. It is important for us as users of the ocean to grasp what effects ocean acidification could have on us as individuals, the most obvious being the effects on the sea food industry. While the directly affected pteropods may seem insignificant to some, fish use them as a source of food.

Solutions and Prevention of Ocean Acidification

Human intervention is critical to preventing further ocean acidification. The carbon dioxide emission are primarily coming from the burning of fossil fuel and deforestation. Fossil fuel (coal, oil or gas) is what is used for modern transportation, power plants, and factories. Deforestation has a resembling effect. Deforestation also lets off high amounts of carbon dioxide, as well as a removal of natural Co2 absorption. Clusters of plant life, such as forests and sea weed in the ocean, serve as a “carbon sink” which absorbs some carbon dioxide. So, not only does deforestation emit carbon dioxide, it creates more imbalance of natural carbon dioxide absorption vs. emission.

To go about preventing ocean acidification, we need to see what the Industrial Revolution has done to pollute the air. While some prevention precautions need to be taken by corporations and communities, there are things that can be done on an individual level, as well. The main way this can be done is to use less energy, in any fashion. The use of less fossil fuel will let off less carbon dioxide, and the use of less electricity will decrease the fossil fuel burning of power plants. The use of less products will also make a positive impact. Buying them increases their demand, requiring more to be made in factories, or otherwise. This will lead to less fossil fuel burning used for production, in turn, letting off less carbon dioxide. Another way to preserve the environment on an individual it the adjustment of our transportation. The best way to do this is use more public transportation, such as busses, but this may not be convenient for some. However, choices like which vehicle you choose to drive and getting it serviced regularly can make a difference.

Conclusion

The preservation of natural habitats is crucial in the battle against climate change. With the number of these places dwindling, it is more important now than it ever has been to do our part to protect them. For example, you can fund these areas by going to natural parks. It is also advisable to purchase items that don’t involve deforestation, and, of course, donating to the cause of ocean acidification directly. Not only this, but eating fish and fishing can help to keep the ocean and coral reefs balanced overall, as well as choosing options that are considered “green”. 

References

1. Logan, S. (2022). Ocean Acidification: The Other Carbon Dioxide Problem. National Oceanic and Atmospheric Administration (NOAA). 
2. Zachos, J. C. (2001). Trend, Rhythm, and Randomness: Nonlinearity in Sediment Geochemistry and Implications for Seawater Chemistry. Geochemistry, Geophysics, Geosystems, 2(12), 1-12.
3. Cheryl, L. (2009). Impacts of Ocean Acidification on Marine Fauna and Ecosystems: A Summary of Current Research Findings and Recommendations for the Future. Integrated Marine Biogeochemistry and Ecosystem Research, 2009: 31-40.
4. Inter Academy Panel Statement on Ocean Acidification 2009. 
5. WWF (World Wildlife Fund). (2015). Reviving the Ocean Economy: The Case for Action—2015.