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Data Series 883
1U.S. Geological Survey, St. Petersburg, FL 33701.
2University of South Florida, College of Marine Science, St. Petersburg, FL 33701.
U.S. Department of the
Interior
U.S.
Geological Survey
St.
Petersburg Coastal and Marine Science Center
Publications are available from USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0046 (telephone 1-888-ASK-USGS; e-mail: infoservices@usgs.gov).
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This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
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Atmospheric carbon dioxide (CO2) is absorbed by the ocean’s surface where it combines with seawater to form a weak, naturally occurring acid called carbonic acid (H2CO3). Increasing carbon dioxide in the atmosphere results in the absorption of more CO2 by the ocean and, therefore, increases in the acidity of seawater. This process, known as ocean acidification, has the potential to elicit change in ecosystems and organisms by disrupting biological processes. For example, ocean acidification is a problem for marine organisms such as corals, foraminifera, and algae that precipitate calcium carbonate to form their skeletons and shells (Kleypas and others, 2006). The effects are related to corresponding changes in the carbonate saturation state (Ω), where Ω is the ratio of the ion concentration product (Ca2+ x CO32-) to the stoichiometric aragonite solubility product (K*sp) (Langdon and Atkinson, 2005). Because pH and CO32- are strongly interdependent through the inorganic carbon system, the decrease in pH will cause a proportionally greater decrease in CO32-.
Globally, ocean acidification is occurring faster than at any time in the last 300 million years (Broeker and others, 1979). Recent evidence indicates that individual oceans are responding at different rates, depending on physical and biological processes. For example, in the Arctic Ocean, the rate of saturation state decrease was 2.1 percent per year between 1997 and 2010 (Robbins and others., 2013) in an area as large as Montana, largely because of increases in melt of ice, versus the average rate observed for the Pacific Ocean (0.36 percent per year) (Feely and others., 2012). Unfortunately, comparative data sets over multiyear time frames are often not available because time series baseline carbon information has not been collected in many oceans. Data are needed in subtropical latitudes where carbonate saturation states are already naturally low and fluctuate seasonally. These data will help construct a baseline for the assessment of future changes.
As part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program project "Response of Florida Shelf Ecosystems to Climate Change," and in partnership with Kendra Daly, University of South Florida (USF), data on surface ocean carbonate chemistry were collected on five cruises along transects on the shallow inner west Florida shelf and northern Gulf of Mexico in 2012. Data from the 2011 cruises were also published (Robbins and others, 2013). The data collected will allow the USGS, National Oceanic and Atmospheric Administration (NOAA), and USF scientists to map variations in ocean chemistry including carbonate saturation states along designated tracks. The USGS is also partnering with NOAA and the National Aeronautics and Space Administration (NASA) to model air-sea flux as part of a Gulf of Mexico Carbon Synthesis project lead by NASA.
During February, April, May, June and August of 2012, the USGS and USF conducted geochemical surveys on the west Florida Shelf to investigate the effects of climate change on ocean acidification within the northern Gulf of Mexico, specifically the effect of ocean acidification on marine organisms and habitats. The cruises were conducted February 15 to 24 (12BHM01), April 24 to 29 (12BHM02), May 8 to 17 (12BHM03), June 29 to July 1 (12BHM04) and August 2 to 12 (12BHM05). To view each cruise's survey lines, please see the Trackline page. Cruises took place aboard the Research Vessels (R/V) Weatherbird II and Bellows, ships of opportunity led by Kendra Daly, USF, which departed from and returned to St. Petersburg, Florida.
Samples were collected from the surface and the water column, and were analyzed in the lab for pH, dissolved inorganic carbon (DIC) or total carbon dioxide (TCO2), and total alkalinity (TA). Lab analysis was augmented with a continuous flow-through system, referred to as sonde data, with a conductivity-temperature-depth (CTD) sensor, which also recorded salinity and pH. Corroborating the USGS data are the vertical CTD profiles, referred to as station samples, collected by USF. The CTD casts measured continuous vertical profiles of oxygen, chlorophyll fluorescence and optical backscatter. Discrete samples for nutrients, chlorophyll, and particulate organic carbon/nitrogen were also collected during the CTD casts. Two autonomous flow-through (AFT) instruments recorded pH and CO2,referred to as AFT data, every 3 to 5 minutes on each cruise.
This report is divided into six sections: Abbreviations, Disc Contents, Methods, Cruise Data, Federal Geographic Data Committee (FGDC) Metadata, and Trackline. Links at the top and bottom of each page provide access to these sections. This report contains links to the USGS, collaborators, and other available resources if access to the Internet is available while viewing these documents. Geographic information system (GIS) files, HyperText Markup Language (HTML) files, and images used to produce the Web pages are also included in this report. The Disc Contents page contains a listing with locations and links to all files and folders contained on this disc.
To access the information contained on this disc, use a Web browser to open the file index.html.
Bates, N.R., 2007, Interannual variability of the oceanic CO2 sink in the subtropical gyre of the North Atlantic Ocean over the last 2 decades: Journal of Geophysical Research—Oceans (1978–2012), v. 112, no. C9, 26 p., accessed July 30, 2014, at https://dx.doi.org/10.1029/2006JC003759.
Broecker, W.S., Takahashi, T., Simpson, H.J., and Peng, T.H., 1979, Fate of fossil fuel carbon dioxide and the global carbon budget: Science, v. 206, no. 4417, p. 409–418. [Also available at https://dx.doi.org/10.1126/science.206.4417.409.]
Dickson, A.G., Sabine, C.L., and Christian, J.R., eds., 2007, Guide to best practices for ocean CO2 measurements: Sidney, British Columbia, Canada, North Pacific Marine Science Organization, PICES Special Publication no. 3, IOCCP report no. 8, 191 p., accessed July 30, 2014, at http://cdiac.ornl.gov/oceans/Handbook_2007.html
Feely, R. A., Sabine, C.L., Byrne, R.H., Millero, F.J., Dickson, A.G., Wanninkhof, Rik, Murata, Akihiko, Miller, L.A., and Greeley, Dana, 2012, Decadal changes in the aragonite and calcite saturation state of the Pacific Ocean: Global Biogeochemical Cycles, v. 26, no. 3, 15 p., accessed July 30, 2014, at https://dx.doi.org/10.1029/2011GB004157.
Kleypas, J.A., Feely, R.A., Fabry, V.J., Langdon, Chris, Sabine, C.L., Robbins, L.L., 2006, Impacts of ocean acidification on coral reefs and other marine calcifiers: A guide for future research—Report of a workshop sponsored by the National Science Foundation, the National Oceanic and Atmospheric Administration, and the United States Geological Survey: Boulder, Colo., University Corporation for Atmospheric Research, 88 p. [Also available at http://www.ucar.edu/news/releases/2006/report.shtml.]
Langdon, C., and Atkinson, M.J., 2005, Effect of elevated pCO2 on photosynthesis and calcification of corals and interactions with seasonal change in temperature/irradiance and nutrient enrichment: Journal of Geophysical Research, v. 110, no. C9, 16 p., accessed July 30,2014, at https://dx.doi.org/10.1029/2004JC002576.
Orr, J.C., and others, 2005, Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms: Nature, v. 437, no. 7059, p. 681–686, accessed July 30, 2014, at https://dx.doi.org/10.1038/nature04095.
Robbins, L.L., Knorr, P.O., Daly, K.L., Taylor, C.A., Barrera, K.E. 2014, USGS Field Activities 11BHM01 and 11BHM02 on the west Florida shelf, Gulf of Mexico, May and June 2011: U.S. Geological Survey Data Series report 712, 7 p. accessed July 30, 2014, at https://dx.doi.org/10.3133/ds/712/.
Sabine, C.L. Feely, R.A., Key, R.M., Bullister, J.L., Millero, F.J., Lee, K., Peng, T.-H., Tilbrook, B., Ono, T., and Wong, C.S., 2002, Distribution of anthropogenic CO2 in the Pacific Ocean: Biogeochemical Cycles, v. 16, no. 4, pp. 30-1–30-17, accessed July 30, 2014, at https://dx.doi.org/10.1016/S0967-0637(98)00018-1
Yao, Wensheng, and Byrne, R.H., 1998, Simplified seawater alkalinity analysis: Use of linear array spectrometers: Deep-Sea Research Part I—Oceanographic Research Papers, v. 45, no. 8, p. 1383–1392, accessed July 30, 2014, at https://dx.doi.org/10.1016/S0967-0637(98)00018-1.
Robbins, L.L., Knorr, P.O., Daly, K.L., and Barrera, K.E., 2014, USGS field activities 12BHM01, 12BHM02, 12BHM03, 12BHM04, and 12BHM05 on the west Florida shelf, in February, April, May, June, and August 2012: U.S. Geological Survey Data Series 883, https://dx.doi.org/10.3133/ds883.