The Pacific Ocean and its marginal seas are actively enrolled in the global carbon cycle via fast CO2exchange with the atmosphere and intensive land-ocean interactions. Increased absorption of anthropogenic CO2 has led to a remarkable pH decline (acidification) in surface water of some marginal seas, endangering pelagic phytoplankton communities. With acidified water penetrating into depth, the carbonate system of deep marginal seas will also be influenced accordingly, though how these changes will proceed among different basins are still not fully understood. By studying sedimentary calcium carbonate distributions in several Pacific (sub)Basins, and large Western Pacific marginal seas, we systematically quantify how their spatial variability is shaped by the regionally heterogeneous environmental conditions. Our results suggest that the carbonate chemistry in deep marginal sea basins is generally governed by the global ocean thermohaline circulation. The carbonate system in the deep Japan/East Sea provides a unique test ground for acidification in an ocean environment with limited biological alkalinization.

西太平洋,边缘海,碳酸钙,沉积