The figure below from the NOAA State of the Science FACT SHEET on ocean acidification shows carbon dioxide concentrations in the atmosphere and sea surface (top)
and pH and concentration of carbonate ion in the sea surface (bottom) over time. Refer to
the figure to answer the following two questions.
2)
(3 pts.) Explain the relationship between seawater CO
2
concentration and seawater pH. Why does pH decrease as CO
2
concentrations increase?
CO2 concentration in seawater impacts the sea waters pH. When CO2 concentration increases, it acidifies the seawater more, which then lowers the pH since the water becomes more acidic than before.
3)
(1 pt.) Does the carbonate concentration increase
or decrease
as seawater pH decreases? Type increase or decrease into the text box provided.
Decrease
4)
(1 pt.) Why is calcium carbonate (CaCO
3
-2
, AKA aragonite) important?
Multiple choice question, possible answers:
Molting organisms, like crabs, use it to regulate their pH as they molt
Fish use it in their gills to increase the amount of oxygen they get from seawater
