Ocean Acidification

Global warming is often thought as the only potential impact of an influx of carbon dioxide on the environment. However, what has been called its “evil twin”, ocean acidification, is similarly problematic.

What is this process?

pH is how acidic or basic an aqueous solution is. As the levels of carbon dioxide increase in the atmosphere, about a quarter dissolves into the ocean. This causes pH value to decrease and the ocean becomes more acidic.

What are the ramifications of ocean acidification?


As the ocean becomes more acidic, several problems arise. First, coral reefs may be eroded. The coral reef pictured is bleached as a result of increased acidity. Next, plankton shells become weaker and thinner because of acidification, which may impact entire marine food chains. Further, every shelled marine animal faces a similar fate. The process is happening quickly. From 1750 to 1994, acidity has increased about 30 percent, a fall of roughly 0.1 pH units.

Studies about the effects of ocean acidification

One study, published in the June 2011 issue of Fish and Fisheries, discusses the potential global impact of ocean acidification. As soon as the next 10 to 50 years, countries that depend on shellfish as a protein-source may see their economy falter.

Another study exposed clownfish, who use hearing to detect coral reefs that may house predators, to a mixture of salt water and carbon dioxide. Levels were adjusted to predictions of the Intergovernmental Panel on Climate Change. The clownfish that were exposed to the mixture were no longer able to detect predators.

Oceana has found the following: that more than a third of the world’s population will be affected by acidification; that the world's largest carbon dioxide emitters will likely be among those most affected; that all nations that catch or eat fish, or depend on coral reefs for tourism, storm protection, or food may be affected.

What is being done to solve the problem of ocean acidification?


The Bodega Ocean Acidification Research consortium is “examining spatial and temporal changes in seawater chemistry and the impacts of this variability on the ecology, physiology, and biomechanics of critical near-shore marine invertebrates”.

In addition to this research, the Lautenberg Ocean Acidification bill was signed into law by President Obama in 2009. This law “provide(s) the needed research to analyze and address the environmental and economic impacts of ocean acidification.”

The Environmental Protection Agency will evaluate the impact of ocean acidification on water quality and to examine if the water quality criterion currently in place needs to be changed. Biological assessment methods will be introduced to evaluate the health of coral reefs.

Also see NOAA’s Ocean Acidification page.