Kim, D.; Choi, S.-H.; Yang, E.-J.; Kim, K.-H.; Jeong, J.-H., and Kim, Y.O., 2013. Biologically mediated seasonality of aragonite saturation states in Jinhae Bay, Korea.

Aragonite saturation states (Ω_arag) were estimated for the surface and bottom waters of Jinhae Bay over four seasons to assess the major controlling factors. The surface and bottom waters of Jinhae Bay were highly supersaturated with respect to aragonite in spring, autumn, and winter. In summer, however, most of the bottom waters were undersaturated, even though the surface waters were supersaturated. This can be explained by the phytoplankton–carbonate saturation state interaction; high primary production increases Ω_arag in surface waters, whereas vertical export and the subsequent remineralization of organic matter decreases Ω_arag in subsurface waters. A strong linear correlation between the Ω_arag values and dissolved oxygen concentrations supported the idea that biological activity is a major factor controlling Ω_arag in Jinhae Bay. The ocean acidification induced by the invasion of anthropogenic CO₂ also considerably affected the aragonite saturation state in all seasons, particularly in winter, when the Ω_arag values have been reduced by 32–35% in the surface waters and 33–37% in the bottom waters since the preindustrial era. In Jinhae Bay, the undersaturation with respect to aragonite in summer can have large impacts on the calcifying benthic organisms; mussel calcification may no longer occur, and the oyster calcification rate is probably reduced by 50%. In addition, the pH and Ω_arag decreases associated with the anthropogenic CO₂ increase may reduce the calcification rates of oyster and mussel in all seasons, particularly in winter.