This article is about a PBS TV report which tries to wrap the issue up into a nice neat package as all TV reports must. One important thing to know is that natural changes in PH easily swamp the changes caused by CO2 produced by man. Any report promoting concern about this, that does not make very clear the huge difference between the two is going to be deceptive.
some links in the comments:
How Corals Can Overcome Ocean Acidification & Global Warming
Volume 15, Number 50: 12 December 2012