Ocean acidification, generated by the uptake of carbon dioxide (CO2), is an emergent global change related stressor which has the potential to affect a large range of marine organisms and ecosystems. Seas and oceans play a key role in the global carbon cycle because they are a key CO2 sink (Gattuso and Hansson, 2011). Continuous anthropogenic emissions of CO2 into the atmosphere and uptake by the oceans cause more CO2 to dissolve in seawater, reducing pH and saturation state (Ω; Andersson et al., 2008) of CaCO3 minerals from which marine calcifiers build their shells and skeletons (Ries, 2011).