Earth’s Future Ocean:
Acidic or Basic?
Miriam Sutton, M.A., NBCT
Carteret County Schools
Beaufort, North Carolina
Research Question
How do changes in the chemistry of the ocean affect
marine organisms?
Experimental Phase I
1 - Add 3mL of each liquid to the corresponding
cup.
2 - Use pH test strips to determine the pH of each
liquid.
3 - Record the pH for each liquid on your data
table.
4 - Predict the level of pH that will create a
chemical reaction with calcified shell fragments.
Make your Prediction
1 - Add 1/2 teaspoon of
shell fragments to each
cup of liquid.
2 - Record your
observations on your data
table.
Experimental Phase II
Test Your Prediction
Analyze Your
Results
1 - Which liquid(s) resulted in a chemical reaction with
the calcified shell fragments?
2 - What was the pH of the liquid(s) that resulted in a
chemical reaction with the calcified shell fragments?
Chemically Speaking
What happened to the seashells?
What’s going on chemically?
Vinegar + Seashells => Crystals* + Bubbles
Acetic acid + Calcium carbonate => Calcium acetate + Carbon dioxide
(A double displacement chemical reaction)
*Crystals will form in a few days.
pH Analysis
Analysis with pH scale
Vinegar pH = 2.9 Seawater pH = 8.2
Since the Industrial Revolution, the pH of
seawater has dropped about 0.1, bringing
the average seawater pH to 8.1.
By 2100, the pH of seawater is predicted
to drop another 0.1 - 0.35, which would
result in a Seawater pH = 8.0 - 7.65
Trends & Predictions in Ocean pH
Questions to Ponder
Will the predicted drop in seawater pH have
a detrimental effect on all marine
organisms? Why or Why not?
Will the change in seawater pH occur at a
rate at which marine organisms can adapt?
Other thoughts or questions?
Additional Resources
• NOAA/PMEL Carbon Group, National Oceanic and Atmospheric Administration.
Ocean Acidification, What is Ocean Acidification? Seattle, WA.
http://www.pmel.noaa.gov/co2/OA/background.html
• NOAA: United States Department of Commerce. State of the Science FACT SHEET.
Ocean Acidification. May 2008. http://www.oceanacidification.net/OAdocs/FactSheet_en.pdf
• Effects of Climate Change and Ocean Acidification on Living Marine
Resources. (Scott Doney, Senior Scientist, Marine Chemistry & Geochemistry
Department, Woods Hole Oceanographic Institution.) Written testimony presented to
the U.S. Senate Committee on Commerce, Science and Transportation’s
Subcommittee on Oceans, Atmosphere, Fisheries, and Coast Guard, May 10, 2007.
http://www.whoi.edu/page.do?pid=8916&tid=282&cid=27206
• Jewett, Libby. NCCOS: Center for Sponsored Coastal Ocean Research: Proposed
Initiatives – Ocean Acidification. NOAA. February 11, 2010.
http://www.cop.noaa.gov/stressors/climatechange/current/ProposedInitiatives/ocean_
acid.aspx
Earth’s Future Ocean:
Acidic or Basic?
Miriam Sutton, M.A., NBCT
Carteret County Schools
Beaufort, North Carolina
miriam.sutton@carteretk12.org
252.223.3482