Climate Change in the Pacific Region
Pacific Region


Ocean Acidification in the Pacific Northwest


High carbon dioxide causes increasingly acidic ocean water resulting in cascading effects for the aquaculture industry and the marine food webs. Carbon dioxide in the atmosphere mixes with ocean water and decreases the pH, resulting in more acidic oceans. In the Pacific Northwest, marine and coastal waters are potentially at a higher risk due to local effects of the California Current System. Over the past 250 years, since the beginning of the industrial revolution, there has been a slow but steady increase in the acidity of the ocean. More recent ocean observations show that the rate of acidification has sped up in the past 14-year survey record.

Virtually every major biological function of marine organisms responds to acidification changes in seawater, including photosynthesis, respiration rate, growth rates, calcification rates, reproduction, and recruitment. Much of the attention has been given to shell-building marine animals that can have their shells erode away before they can grow, causing deformation and/or death. Any animal that forms a shell is affected by this, but some more obvious ones include those we like to eat, such as mussels and oysters. The aquaculture industry depends on being able to grow these animals to sell to restaurants and markets, and with rising acidity these farmers are finding it harder and harder to grow young shellfish and keep their businesses running.  It’s not just humans that like to eat animals with calcium carbonate shells, but many animals of all sizes that form the biotic system of marine fishes and mammals that are at risk if this valuable food source decreases.




Distribution of the depths of more acidic water (pH <7.75) on the continental shelf of western North America from Queen Charlotte Sound, Canada, to San Gregorio Baja California Sur, Mexico. (Feely et al., 2008)


Learn more and read about the research that provided the information above by checking out the links below:

Barton, A. Hales, B., Waldbusser, G.G., Langdon, C., Feely, R.A., 2012, The Pacific oyster, Crassostrea gigas, shows negative correlation to naturally elevated carbon dioxide levels: Implications for near-term ocean acidification effects, Limnol. Oceanogr., 57(3), 2012, 698-710 | DOI: 10.4319/lo.2012.57.3.0698

Doney, S.C., Fabry, V.J., Feely, R.A. 2009. Ocean Acidification: The Other CO2 Problem. Annu. Rev. Marine. Sci. 2009.1:169-192. Download at

Feely, R. A., C. L. Sabine, R. H. Byrne, F. J. Millero, A. G. Dickson, R. Wanninkhof, A. Murata, L. A. Miller, and D. Greeley. 2012.  Decadal changes in the aragonite and calcite saturation state of the Pacific Ocean, Global Biogeochem. Cycles, 26, GB3001, doi:10.1029/2011GB004157

Feely, R.A., Sabine, C.L., Hernandez-Ayon, M., Ianson, D., Hales, B. 2008.  Evidence for Upwelling of Corrosive "Acidified" Water onto the Continental Shelf. Science320, 1490 (2008); DOI: 10.1126/science.1155676

Gruber et al., 2012.  Rapid Progression of Ocean Acidification in the California Current System.  Science 337, 220 (2012); DOI: 10.1126/science.1216773

Hönisch, B. et al.  2012.  The Geological Record of Ocean Acidification.  Science.  2 March 2012 Vol 335, pp. 1058-1063

NRC, National Research Council. 2010. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean

Washington State Blue Ribbon Panel on Ocean Acidification (2012): Ocean Acidification:
From Knowledge to Action, Washington State’s Strategic Response. H. Adelsman and
L. Whitely Binder (eds). Washington Department of Ecology, Olympia, Washington. Publication no. 12-01-015.


Last updated: August 5, 2013

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