Catch the "agenda" in another scare !
There is no global database of pH variability in the oceans. Dore et al. (2009) uses data from station ALOHA to document a “decreasing trend” of pH, “which is indistinguishable from the rate of acidification expected from equilibration with the atmosphere.”
Dore et al. (2009) Physical and biogeochemical modulation of ocean acidification in the central North Pacific. PNAS July 28, 2009 vol. 106 no. 30:12235–12240
Despite the urgency ( sure, "sell" the agenda ) of the ocean acidification problem, there are few available data sets directly documenting its long-term (decadal to interdecadal) rate or its shorter-term (seasonal to interannual) variability. Repeat hydrography has been used to document a decadal increase in the inventory of DIC in the Pacific (8); however, the technique has not yet been applied to the detection of pH changes. Long-term trends in pCO2oce globally have also been documented from large data synthesis efforts, but these results do not directly address pH and are confined to the surface layer.