By Eva Hu
Since the beginning of the industrial revolution, the concentration of the carbon dioxide in the atmosphere has increased due to carbon dioxide emissions from the burning of fossil fuels. The increase in carbon dioxide levels has directly impacted the acidity of the ocean due to the ocean absorbing around a quarter to a third of the carbon dioxide in the atmosphere, increasing its acidity by around 30%. As the levels of carbon dioxide in the atmosphere continue to increase, the amount of carbon dioxide absorbed by the ocean increases as well. This phenomenon of increasing acidity in ocean waters is otherwise known as ocean acidification.
Ocean acidification occurs when carbon dioxide is absorbed by seawater and reacts with water molecules to form carbonic acid. Carbonic acid is then broken down into hydrogen ions and bicarbonate and the increase in hydrogen ions causes the pH of the waters to lower. In addition to this process, some of the hydrogen ions also combine with the carbonate ions present in the ocean to form more bicarbonate, causing the supply of carbonate ions that is used by many marine structures for building to deplete.
Ocean acidification affects a variety of marine creatures, both calcifying and non calcifying organisms. For calcifying organisms such as sea urchins, oysters, corals, and clams, carbonate atoms are an important building block for their calcium carbonate shells. A decrease in these carbonate atoms can make it hard for them to form and maintain their structures, and for organisms such as corals and planktons, up to a million species that be directly affected as they rely on these structures as a habitat and organism as a food source.
The photos above show a pteropod's shell dissolving over 45 days when placed in sea water with pH and carbonate levels projected for the year 2100.
For non-calcifying organisms such as pollock and clownfish (poor nemo :I), ocean acidification has increased the risk of predation of these fishes. Research has shown that the increase in acidity has decreased their ability to detect predators, having difficulty in distinguishing between their own species and predators. However photosynthetic organisms such as seagrass and photosynthetic algae seem to benefit from the increased amount of carbon dioxide as their survival depends on carbon dioxide as much as plants do on land.
Ocean acidification can also impact occupations as well. Coastal areas that are most vulnerable to this phenomenon include the Gulf of Mexico and Alaska. In the Gulf of Mexico, the nutrient pollution combined with carbon pollution is speeding up the acidification in a much faster pace than scientists have anticipated, and can potentially harm up to $10 billion fishing industry. In Alaska, where up to half of the seafood is caught in the country, the decrease in pH can put up to 700,000 jobs at risk.
If we continue to do as we please, the future generations will suffer as a result of our actions. Based on the current level of carbon dioxide emissions, researchers estimate that the ocean will face a 150% increase in acidity, something that earth has not experienced for nearly 20 million years. It will also be detrimental for up to 2 billion people that rely on fish as their main source of protein. There are many ways to reduce your carbon footprint, and by doing so, you can help slow down or even stop the process of ocean acidification.
More information regarding ways to reduce your carbon footprint can be found on: https://blogs.ei.columbia.edu/2018/12/27/35-ways-reduce-carbon-footprint/
Works Cited
August 13, 2015 Perrin Ireland. “What You Need to Know About Ocean Acidification.” NRDC, 23 Oct. 2019,
“Climate Interpreter.” The Chemistry Of Ocean Acidification | Climate Interpreter, 2020,
climateinterpreter.org/content/chemistry-ocean-acidification.
“Ocean Acidification.” Ocean Acidification | National Oceanic and Atmospheric Administration, 2020,
www.noaa.gov/education/resource-collections/ocean-coasts-education-resources/ocean-acidification.
“What Is Ocean Acidification?” Center for Environmental Visualization, 2020,
www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F.
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