Ocean Acidification: Changing Waters Challenge Global Fisheries and the Shellfish Industry

Natalie Schafer

The Blue Planet
Typically, when people hear the word “ocean” they instantly travel to a beach state of mind. However, oceans do more than provide a place to vacation; they play a major role in the planet’s climate system.  These waters provide various and unique habitats for species and are a vital economic resource.  In the United States, the majority of the U.S. population lives 50 miles from shore, and the fishing industry provides people with over 2 million jobs and brings in products valued at an estimated $160 billion.

Photo by Sacha Styles  | Unsplash

More Under the Surface
Naturally, the ocean absorbs approximately 30% of carbon dioxide from the atmosphere; and according to The Climate Reality Project, “since the beginning of the Industrial Revolution, oceans have absorbed an estimated 525 billion tons of carbon dioxide from the atmosphere” (The Climate Reality Project, 2016).  Due to the elevated levels of carbon dioxide in our atmosphere, as the result of our unsustainable land use and industrial methods, the concentration of the absorbed carbon dioxide has increased dramatically, which causes the water to become acidic (this is due to the additional hydrogen atoms). This increase of acidity is known as ocean acidification and is a serious issue since a slight change in pH (acidification) is a considerable change in the marine environment.  

“Climate Change’s ‘Evil Twin’: Ocean Acidification” by Carol Smith is licensed under CC BY-ND 3.0.

This is a problem because in more acidic environments, carbonate ions, which can be described as the “building blocks” of shells, are not as abundant as they are found most frequently in more basic waters (In general, water with a pH lower than 7 is considered acidic, while water with a pH greater than 7 is considered basic). Since there is a lack of these ions, the environment is no longer sufficient for shellfish. Depending on the level of the acidity, the lowered pH is essentially “dissolving” the shellfish in these acidic waters.  Many animals, including terrestrial species, are migrating, or are dying due to not being able to support themselves in these changing, unhealthy environments. 

A Seasick Industry
Ocean acidification poses serious threats to marine ecosystems, and is threatening many companies involved in the shellfish and fish industries.  The United States Environmental Protection Agency (EPA) predicts there will be an even greater decrease in shellfish as conditions become worse.  As a result of the depletion of shellfish, there will be a significant financial loss. Additionally, since there will be less supply per year, the prices of shellfish will rise. The concern with these prices is that they cannot be met by all consumers because of social and economic pressures.  It is estimated by the EPA there will be “consumer losses of roughly $480 million per year by the end of the century.” (EPA, 2019).

Figure 2: Estimated Impacts on the U.S. Shellfish Industry from the EPA Climate Action Benefits Report

Beyond economics the global population relies on the marine ecosystem services that these shellfish provide, such as improving water quality through filtration, reducing shoreline erosion, and stabilizing sediments in estuaries.  This decrease in shellfish will lead to the degradation of other marine ecosystems, depletion of other aquatic life and the overall decline and possible collapse of the shellfish and fishing industries, which supply the human population with a source of protein not to mention thousands of jobs.

The Need to Dive Deeper
The concept of Ocean Acidification is still very young because we still do not know much about it and how to manage the changing waters. Ocean acidification affects many, many organisms besides shellfish.  Multiple communities are concerned with a predicted large-scale dying of marine life.  

“The chemistry of the oceans is changing. And it isn’t just the corals and the baby oysters that are unhappy. It makes juvenile rockfish really anxious, and it upsets the digestion of sea urchins.” – Tim Radford, Climate Home News – 2013

In addition to this relatively new issue, we still have much more of our oceans to explore.  Scientists have described “being decades behind in [ocean] research compared to land and other environments” (personal communication with Kristin Burkholder, Stonehill College). By not having as much knowledge about the oceans and how its ecological processes function, many find it difficult to find long term solutions to ocean acidification. 

“Seas” the Day
Though it is not known if ocean acidification can be reversed or stopped, slowing down the rate of ocean acidification will benefit future generations. In order to do this the amount of carbon dioxide absorbed by the oceans must decrease.  Here are some ways to decrease the amount of carbon dioxide that you generate in your day-to-day life, also referred to as your “carbon footprint”:

  • Turn off the lights when you are not using them
  • Buy local produce
  • Walk, cycle, carpool, or make use of public transportation
  • Refuse, reduce, reuse, repair, recycle
  • Use “green electricity” (e.g. solar panels)
  • Minimize water usage
  • Compost to reduce food waste
  • Eat less red meat or cut it out entirely 
  • In general, be aware of where your food comes from and try to support local businesses which cuts down on emissions from transportation

To learn more about the shellfish industry and opportunities to get involved, visit your local shellfish farmer and ask about which methods they are using to combat ocean acidification! There are also various research projects involving the use of shellfish and/or ocean acidification. Check out volunteer opportunities at your local colleges/universities; multiple universities need volunteers for research projects!

National/ Global Projects:

Volunteer Opportunities:

Sources: Climate Home News, EPA, NOAA, Seattle Magazine, Smithsonian, Stonehill College, The Climate Reality Project, The Ocean Foundation, The Scientist Magazine, United Nations Development Programme, United Nations University, Unsplash, ZME Science