Impacts of Ocean Acidification

"Ocean acidification is expected to impact ocean species to varying degrees. Photosynthetic algae and seagrasses may benefit from higher CO2 conditions in the ocean, as they require CO2 to live just like plants on land. On the other hand, studies have shown that lower environmental calcium carbonate saturation states can have a dramatic effect on some calcifying species, including oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton. Today, more than a billion people worldwide rely on food from the ocean as their primary source of protein. Thus, both jobs and food security in the U.S. and around the world depend on the fish and shellfish in our oceans." - NOAA: What is Ocean Acidification?

Coral

"Many marine organisms that produce calcium carbonate shells or skeletons are negatively impacted by increasing CO2 levels and decreasing pH in seawater. For example, increasing ocean acidification has been shown to significantly reduce the ability of reef-building corals to produce their skeletons. In a recent paper, coral biologists reported that ocean acidification could compromise the successful fertilization, larval settlement and survivorship of Elkhorn coral, an endangered species. These research results suggest that ocean acidification could severely impact the ability of coral reefs to recover from disturbance. Other research indicates that, by the end of this century, coral reefs may erode faster than they can be rebuilt. This could compromise the long-term viability of these ecosystems and perhaps impact the estimated one million species that depend on coral reef habitat." - NOAA: What is Ocean Acidification?

Shellfish

Shellfish Farmers & Fishing Industry

"researchers project acidification could reduce U.S. shellfish harvests by as much as 25 percent over the next 50 years."

"... Because, as we continue to release more and more CO2 in the atmosphere, and that will be taken up by the oceans, eventually, the oceans will be corrosive 50 percent of the time or 60 percent of the time within the next 30 or 40 years.

This would be a 100 percent to 150 percent increase of the acidity of the oceans by the end of the century. This is a very dramatic change that has not been seen in the world oceans for more than 50 million years." - NOAS: Ocean Acidification' impact on Oysters and Other Shellfish 

Ways to Reduce Acidification

"Oystermen have been working with scientists to find ways to adapt. Hatcheries now monitor seawater and only allow it in when acidity levels are lower. They're also adding sodium carbonate and eelgrass to help balance the pH levels. That's helped growers recover nearly 75 percent of their losses.

But Dick Feely says that strategy won't work in the future, when scientific models show corrosive waters will become more pervasive at the sea surface.

... Because, as we continue to release more and more CO2 in the atmosphere, and that will be taken up by the oceans, eventually, the oceans will be corrosive 50 percent of the time or 60 percent of the time within the next 30 or 40 years.

This would be a 100 percent to 150 percent increase of the acidity of the oceans by the end of the century. This is a very dramatic change that has not been seen in the world oceans for more than 50 million years." - NOAS: Ocean Acidification' impact on Oysters and Other Shellfish 

Biological Solutions

Chemical Solutions

Sodium Carbonate 

Oyster farmers have used sodium carbonate to help reduce acidification in hatcheries and oyster farms.  - NOAS: Ocean Acidification' impact on Oysters and Other Shellfish 

Resources

• Ocean Acidification: The Other Carbon Dioxide Problem offers an introduction into ocean acidification along with further links.

• OA Observations and Data learn about the specific technologies and activities used to gather observational data.

• What is Ocean Acidification? learn about the chemistry and biological impacts.

North America

USA

• The PMEL Carbon Group "has been involved in the development of a variety of educational tools for educators, students, and the broader public that describe the ocean carbon cycle and how it is changing over time.  Through these resources, we strive to contribute to NOAA's goal to improve the Nation's fundamental understanding of the systems of the natural world, the relationships and interactions between the living and non-living environment, and the ability to understand and utilize scientific evidence to make informed decisions regarding environmental problems."