The Hawaiian Corals of Oahu's Kaneohe Bay
Shamberger, K.E.F., Feely, R.A., Sabine, C.L., Atkinson, M.J., DeCarlo, E.H. and Mackenzie, F.T. 2011. Calcification and organic production on a Hawaiian coral reef. Marine Chemistry 127: 64-75.
In a study that sheds new light on this subject, Shamberger et al. deployed newly designed "autosamplers" to collect water samples from the barrier coral reef of Kaneohe Bay, Oahu, Hawaii, every two hours for six 48-hour periods, two each in June 2008, August 2009 and January/February 2010. And based on these seawater measurements, they calculated net ecosystem calcification (NEC) and net photosynthesis (NP) rates for these periods.
As expected, the six scientists found that "daily NEC was strongly negatively correlated with average daily pCO2, which ranged from 421 to 622 ppm." Most interestingly, however, they report that "daily NEC of the Kaneohe Bay barrier reef is similar to or higher than daily NEC measured on other coral reefs, even though Ωarag levels (mean Ωarag = 2.85) are some of the lowest measured in coral reef ecosystems [italics added]."
Shamberger et al. conclude the report of their study by saying "it appears that while calcification rate and Ωarag are correlated within a single coral reef ecosystem," as in the case of the barrier reef of Kaneohe Bay, "this relationship does not necessarily hold between different coral reef systems," and they state that it can thus be expected that "ocean acidification will not affect coral reefs uniformly and that some may be more sensitive to increasing pCO2 levels than others," which also means (taking a more positive view of the subject) that some may be less sensitive to increasing pCO2 than others. And in light of what is known about the potential for rapid evolution in corals and their symbionts - see Evolution (Aquatic Life) in our Topical Archive - an even stronger positive view of the subject may be obtained.