12  Ocean Acidification

Description Ocean acidification (OA) occurs when atmospheric CO2 dissolves into seawater, reduces seawater pH and carbonate ion levels. Upwelling transports low oxygen, acidified waters from deeper offshore onto the continental shelf, where increased community-level metabolic activity can further exacerbate OA (Feely et al. 2008). A key measure of OA is aragonite saturation state, which is related to availability of aragonite (a form of the mineral calcium carbonate) to form or dissolve. Aragonite saturation <1.0 indicates relatively acidified, corrosive conditions that are stressful for many CCE species, particularly shell-forming invertebrates. OA impacts on these species can propagate through marine food webs and potentially affect fisheries (Marshall et al. 2017). Aragonite saturation states tend to be lowest during spring and summer upwelling, and highest in winter.

Newport Line Aragonite Saturation

• Locations:
  • 150 m: NH25 (44.7 N, -124.7 E)
  • 40 m: NH05 (44.65 N, -124.18 E)
• Component Category: Climate and Ocean Drivers
• Time Range: 1998 - 2024
• CCIEA Data Contact: isaac.schroeder@noaa.gov
• Institution: NOAA NWFSC
• Source Data: Data are derived from methods in (Juranek et al. 2009): Juranek, L.W., Feely, R.A., Peterson, W.T., Alin, S.R., Hales, B., Lee, K., Sabine, C.L. and Peterson, J., 2009. A novel method for determination of aragonite saturation state on the continental shelf of central Oregon using multi-parameter relationships with hydrographic data. Geophysical Research Letters, 36(24).

Indicator Download

ERDDAP™ link:

https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_ARG.html

References

Feely, Richard A, Christopher L Sabine, J Martin Hernandez-Ayon, Debby Ianson, and Burke Hales. 2008. “Evidence for upwelling of corrosive" acidified" water onto the continental shelf.” Science 320 (5882): 1490–92.

Juranek, L. W., R. A. Feely, W. T. Peterson, S. R. Alin, B. Hales, K. Lee, C. L. Sabine, and J. Peterson. 2009. “A Novel Method for Determination of Aragonite Saturation State on the Continental Shelf of Central Oregon Using Multi-Parameter Relationships with Hydrographic Data.” Geophysical Research Letters 36 (7).

Marshall, Kristin N, Isaac C Kaplan, Emma E Hodgson, Albert Hermann, D Shallin Busch, Paul McElhany, Timothy E Essington, Chris J Harvey, and Elizabeth A Fulton. 2017. “Risks of ocean acidification in the California Current food web and fisheries: ecosystem model projections.” Global Change Biology 23 (4): 1525–39.