title: P/Ca in coral skeleton as a geochemical proxy for seawater phosphorus variation in Daya Bay, northern South China Sea.
abstract: The P/Ca ratio in coral skeletons is considered to be a direct proxy for the nutrient P in seawater. We examined the reliability of this proxy by analyzing P/Ca in a Porites coral collected from a eutrophic area in the northern South China Sea. P concentrations were significantly higher compared to previously reported values from pristine and open seas, corresponding to the elevated nutrients from the study site. We compared coral P/Ca against recent in-situ records of seawater P concentrations. Our results show that P/Ca was primarily a function of TP sw rather than PO(4)sw, and that the signal of skeletal P included not only phosphate, but also organic phosphorus. Besides the form of skeletal P, sub-sampling and analytical procedures and the distinctive nutrient regime were the most reasonable explanations for our results. We suggest that total P in coral skeletons may be an efficient proxy for seawater P variations and associated phytoplankton dynamics in eutrophic environments.
authors.affiliation: Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. chentianran2008@gmail.com
authors.forename: Tianran
authors.initials: T
authors.lastname: Chen
authors.forename: Kefu
authors.initials: K
authors.lastname: Yu
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D061006:Bays / Q000737:chemistry*; D002118:Calcium / Q000032:analysis*; D002681:China; D057894:Coral Reefs; D004784:Environmental Monitoring / Q000379:methods*; D010758:Phosphorus / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D002118:Calcium