Issues > Ocean Acidification

Since the start of the Industrial Revolution, the world's oceans have absorbed 500 billion tons of CO2, roughly one-third of all fossil fuel emissions.1  The resulting chemical shift produced an increase in acidity, and thus a more corrosive environment, which is a great concern.

What do acid oceans mean?

Rising acidity creates a corrosive underwater environment where corals are unable to produce algae and shellfish cannot form shells. If ocean acidity gets high enough, corals will erode faster than they can grow and the ocean environment will literally dissolve calcified shells. Natural Resources Defense Council (NRDC) has likened the phenomenon to “global osteoporosis” as the shellfish in question are not only commercially valuable but also integral to the larger food chain.

Pacific oysters have not successfully reproduced in the wild since 2004. Mussels have been replaced by algae off the coast of Washington. If these species become extinct birds and animals further up the food chain will be affected, including us. For example, Alaskan salmon feed rely on small marine snails for 60 percent of their diet. If Alaskan salmon were to suddenly lose their primary source of protein, and thus spiral into decline, we would feel that immediately. The direct impacts to shellfish are only the beginning.2

People and industries that depend on fisheries will have their lives impacted dramatically by ocean acidification. Calcifying organisms, such as shellfish, provided 110 million metric tons of food for humans in 2006 - an amount valued at $160 billion.3  Fishing, ocean tourism and recreation will disintegrate along with the corals by mid-century unless we develop proactive policies to protect the marine environment. But combating ocean acidification will take a new kind of organization. It’s going to take more than marine protected areas and reversing overfishing. We need to address our national energy policy if we want to save the oceans. As far away and removed as they might seem it is important to remember that oceans represent 70 percent of the planet’s surface and 500 times its weight. What’s more, they are inextricably connected. So a change anywhere is felt everywhere.

Learn More

Watch NRDC's short movie Acid Test

1, Natural Resources Defense Council. Ocean Acidification: The Other CO2 Problem.
Sarah Cooley, Hauke Kite-Powell, and Scott Doney. Ocean Acidification's Potential to Alter Global Marine Ecosystem Services, Oceanography December 2009, Vol. 22, No. 4.

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