Tropical Pacific Ocean Acidification Occuring Much Faster Than Expected, NOAA Finds

pmel-oceanCO2uptakeChange is taking place in the tropical Pacific Ocean, where NOAA (National Oceanic and Atmospheric Administration) researchers have found that carbon dioxide (CO2) concentrations have increased as much as 65 percent faster than atmospheric CO2 since 1998. Rising CO2 concentrations of this magnitude indicate that tropical Pacific waters are acidifying as fast as ocean waters in the polar regions, which may have grave repercussions for marine food webs, biodiversity, fisheries and tourism.

NOAA researchers collected data from CO2 sensors that NOAA Research Pacific Marine Environmental Lab Carbon Group scientists and engineers installed on moored buoys within the Tropical Atmosphere Ocean Array, a network of buoys stretching across the Pacific. The data stretches from 1997-2011, NOAA explains in a press release.

“We have a 30-year record of CO2 collected from instruments on ships, but this new data tell us the tropical Pacific has changed more rapidly in the past 14 years than observed previously,” coauthor and NOAA Senior Scientist Richard Feely was quoted as saying.

Ocean acidification: Threat to those incredible plankton

Amazing as it may seem, microscopic phytoplankton produce over half the oxygen in Earth’s atmosphere. Capable of manufacturing their own food from sunlight and chemical elements found in the oceans, phytoplankton are the primary producers that form the base of the marine food web. Many have calcium carbonate shells.


Ocean waters acidify when the amount of carbon dioxide in the atmosphere increases and the oceans absorb more of it. That threatens not only phytoplankton, but reverberates throughout the marine food web — threatening a wide variety of larger marine life, such as corals, oysters, clams and mussels, as well as marine species that feed or otherwise depend on these species for their growth, development, habitat and survival.

Suggestive of changes in store due to ocean acidification, marine scientists in 2008 reported finding that average shell weights of one large group of phytoplankton they surveyed, foraminifera, were 30 to 35 percent lower than those from specimens dating back thousands of years. Other scientists have predicted that mussel and oyster calcification could decrease significantly over the course of the 21st century.

Changes in the global carbon system

Moreover, the oceans collectively are the largest carbon sink on the planet, absorbing more than 25 percent of fossil fuel emissions annually, NOAA points out. That varies regionally, however. The tropical Pacific, which is responsible for 70 percent of annual variability in global oceanic uptake of CO2, is actually emitting CO2 into the atmosphere at an increasing rate. Hence changes taking place there can affect the global carbon system.

NOAA scientists tentatively attribute the rapid increase in acidity of tropical Pacific waters to a combination of human factors and natural environmental cycles. Higher winds have been prevalent across the region since 1998, a trend believed to be associated with a cyclical pattern of climate variability known as the Pacific Decadal Oscillation. These winds cause upwelling, a process whereby deep ocean waters high in CO2 are driven to the surface, where they mix with surface waters that are enriched with CO2 from human and natural sources.

The NOAA research group’s report, “Natural variability and anthropogenic change in equatorial Pacific surface ocean pCO2 and pH,” has been published in the journal Global Biogeochemical Cycles.

Images courtesy of the National Oceanic and Atmospheric Administration

An independent journalist, researcher and writer, my work roams across the nexus where ecology, technology, political economy and sociology intersect and overlap. The lifelong quest for knowledge of the world and self -- not to mention gainful employment -- has led me near and far afield, from Europe, across the Asia-Pacific, Middle East and Africa and back home to the Americas. LinkedIn: andrew burger Google+: Andrew B Email:

16 responses

  1. The ocean is strongly alkaline, with enormous buffering capacity. There is not enough carbon in all the known fossil fuel resources of the earth to acidify the oceans.

    It is fundamentally deceitful to refer to “ocean acidification” to describe a decrease in the alkalinity of the seas. Please don’t be dishonest.

  2. The oceans are typically at a pH of 8.2. Since the industrial revolution they have dropped to about 8., becoming slightly more acid. That equals acidification. It doesn’t sound like much but a drop of 0.5 pH is biologically very significant. Look up what happened to oyster hatcheries in Washington State. When the pH of the seawater they used dropped to 7.6 it killed entire crops of oyster larvae. They have been losing crops since 2007.

    1. And the pH scale is logarithmic, so each +/- 1.0 change in pH means 10x more or less acidic or basic…

    2. Please cite your fact sources for “The oceans are typically at a pH of 8.2. Since the industrial revolution they have dropped to about 8”. (“Typically” is not a word used in scientific literature. Then see . CO2 from human fossil fuels use is a miniscule portion of overall CO2 sources, and cannot possibly affect seawater acidity.

      The oyster farmers and others who claim to be victims of CO2 emissions had better look to local sources of water pollution. Since agriculture contributes 85% of water pollution, that would be a good place to start. After that, look at municipalities and other government entities, which contribute 10% of water pollution. Manufacturing and extractive industries only contribute 5%

      Let’s examine the deceitful phrasing of “becoming slightly more acid. That equals acidification…..a drop of 0.5 pH is biologically very significant.” No, becoming less alkaline IS NOT the same as becoming more acid. And your implied drop of 0.5 pH IS NOT the same as the drop of 0.2 pH implied by the values you stated.

      Its all about the propaganda with you people. Its no surprise that the general public ignores climate alarmists.

      1. Isn’t it true that as partial pressures of a gas in the atmosphere increase more will be absorbed by the oceans, the world’s biggest carbon sink? And here we have CO2 over this stretch emitting CO2 from increased upwelling from deep ocean waters rich in CO2, again suggesting other than just a local near-term source?

        And here, in a study of data stretching across the Pacific, doesn’t that also argue for something more than just local causes, such as run-off from farms, industry, cities, etc. and are often the biggest pollution problems for fisheries coastal waters (e.g. dead zones)?

      2. Isn’t CO2 from emissions, and natural sources, affecting the pH of seawater all the time? The argument is that it’s the balance that’s important, not merely the absolute amount, and the ongoing rise in human CO2 emissions is tipping that balance, ocean pH with it…
        And isn’t it CO2 that mixes with ocean water to form carbonic acid, which threatens calcium carbonate shell formation?
        Yes, as the following Nat Geo link states, ocean pH has been basic, around 8.2 uniformly across the world’s oceans for about 300 million years…It’s dropped 0.1 to 8.1, a 25% increase in the last 200 years…a period when human emissions have been increasing rapidly…

        Yes, ocean waters are still basic, but they are becoming less basic…Calling that acidification is the flip side of the coin scientifically and semantically, isn’t it? It’s not saying the oceans are acidic, and it’s not propaganda…

    3. I read a whole book about jellyfish taking over the oceans, as they continue to be degraded. There are teams of scientists measuring carbon uptake and acidification.
      Coral bleaching is a good indicator.


  4. The deadly dose of CO2 already administered to air and oceans will continue to acidify the oceans unabated for centuries even if all additional CO2 emissions were to stop tomorrow. The need today is to prevent CO2 from binding to H2O to become H2CO3 death dealing carbonic acid.

    There is just one practical means to do this and that is to replenish and restore ocean photosynthesis, plant life. Ocean plant life, its phyto-plankton, converts CO2 into life itself. Restoring ocean plankton to the state of abundance and health of 50 years ago will convert into life billions of tonnes of CO2 that will without our efforts become death.

    We’ve demonstrated this in our large 2012 project. Our replenished and restored ocean pasture produced the richest plankton blooms ever seen in the NE Pacific. Last fall the results were seen when the fish came back. In Alaska instead of the 50 million Pink salmon predicted 219 million Pinks were caught as they swam to shore from our restored ocean pasture. This is the largest catch of salmon in all of Alaskan history and similar reports of miracle runs of fish are coming in from up and down the Pacific coast.

    Our methods of ocean pasture restoration are inexpensive and immediate and produce astonishing results in terms of restored fish and all ocean life. As a side benefit the USDA has just purchased upwards of 100 million servings of our unexpected bounty of Pink salmon now in Alaskan inventory to provide to US children in its food aid programs.

    Not a bad set of results for me, one grandfather and 11 shipmates doing our best, doing what’s right, for our oceans and our children in the summer of 2012. for more. IT JUST WORKS!

    1. The trouble is that it would take probably a trillion tons of calcium to lower the Ph of all the oceans. Overfishing, overfishing, overfishing. Did they stop at limiting the catches of these pink salmon?

Comments are closed.