Ocean acidification: One potential driver of phosphorus eutrophication

The phosphorus exchange between the two pools depends on phosphorus diffusion flux across sediment-water interface, which is influenced by seawater pH and the forms of phosphorus in sediments. Before ocean acidification, the IP (inorganic phosphorus) and OP (organic phosphorus) content in water and sediments is WIP, WOP, SIP and SOP, respectively. After ocean acidification, the IP and OP content in water and sediments is WAIP, WAOP, SAIP and SAOP, respectively. As the phosphorus biogeochemical cycle belongs to one sedimentary cycle, one mass balance equation is obtained, WIP + WOP + SIP + SOP = WAIP + WAOP + SAIP + SAOP, which means that SIP − SAIP = WAIP + WAOP − WIP − WOP + SAOP − SOP. IF the OP content in sediments is low and its mineralization can be neglected, the released DIP (dissolved inorganic phosphorus) from sediments might be estimated by 1 − SAIP / SIP, which implies that ocean acidification might be one potential facilitator of phosphorus eutrophication in oxic conditions.156