Ocean acidification: One potential driver of phosphorus eutrophication. (15th February 2017)

• Record Type: Journal Article
• Authors: Ge, Changzi; Chai, Yanchao; Wang, Haiqing; Kan, Manman
• Is Part Of: Marine pollution bulletin. Volume 115:Number 1/2(2017)
• Page Start: 149
• Page End: 153
• Publication Date: 2017-02-15
• Subjects: Eutrophication -- Exchangeable phosphorus -- Inorganic phosphorus -- Ocean acidification; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2016.12.016
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Harmful algal blooms which may be limited by phosphorus outbreak increases currently and ocean acidification worsens presently, which implies that ocean acidification might lead to phosphorus eutrophication. To verify the hypothesis, oxic sediments were exposed to seawater with different pH 30 days. If pH was 8.1 and 7.7, the total phosphorus (TP) content in sediments was 1.52 ± 0.50 and 1.29 ± 0.40 mg/g. The inorganic phosphorus (IP) content in sediments exposed to seawater with pH 8.1 and 7.7 was 1.39 ± 0.10 and 1.06 ± 0.20 mg/g, respectively. The exchangeable phosphorus (Ex-P) content in sediments was 4.40 ± 0.45 and 2.82 ± 0.15 μg/g, if seawater pH was 8.1 and 7.7. Ex-P and IP contents in oxic sediments were reduced by ocean acidification significantly (p < 5%). The reduced phosphorus in sediments diffused into water, which implied that ocean acidification was one potential facilitator of phosphorus eutrophication in oxic conditions. Graphical abstract: 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. Highlights: IP content in oxic sediment is reduced by ocean acidification. Ex-P content in oxic sediment is reduced by ocean acidification. Ocean acidification might be one potential driver of phosphorus eutrophication.