Our new paper is out in Global Change Biology! We looked at mineral structure in the California mussel over 2500 years, and found a change only in mussels collected since 2010. The change, summarized above, reveals smaller calcium carbonate crystals, the presence of amorphous calcium carbonate, and greater inter-individual variability in shell chemistry in modern shells.
Check out FSU's press release here: http://news.fsu.edu/news/science-technology/2018/01/05/fsu-researcher-ocean-acidification-means-means-major-changes-california-mussels/#.WlI896Vn96Y.link