title: Phosphorus speciation, transformation, and preservation in the coastal area of Rushan Bay.
abstract: Phosphorus (P) speciation, burial, and transformation are poorly constrained under low-oxygen conditions. Sequential chemical extraction techniques, in-situ incubation, and laboratory incubation were employed to explore P cycling in the low-oxygen area of coastal Rushan. The study determined that the total P concentrations in the coastal area of Rushan Bay were higher than those of other China shelf seas, and largely affected by anthropogenic activities. The phosphate (DRP) fluxes in the study area calculated using an incubation method (0-1960μmolm(-2)day(-)(1)) and measured based on pore water gradients (1.5-50.4μmolm(-2)day(-)(1)) were both highly correlated with oxygen conditions. Sediment incubations showed that DRP diffusion from the sediment mainly originates from Fe-P and Auth-P dissolution and that Org-P recycling contributed only a small portion of the total released P pool. The benthic phosphate flux can be 60 times higher under low bottom-water oxygen levels of 63-150μmolL(-1) than under oxygen levels exceeding 150μmolL(-1) in the study area. The P accumulation rates and burial efficiencies in this study area ranged from 16.5-33.3μmolcm(-2)year(-1) and 81.1-83.4%, respectively, and were regulated by the oxygen level and diffusive DRP flux. This study indicates that low oxygen levels between 63 and 150μmol significantly govern P transformation and preservation in the sediment and P pools in the water column.
authors.affiliation: Research Center for Marine Ecology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China; Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Research Center for Marine Ecology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China.
authors.forename: Jiaye
authors.initials: J
authors.lastname: Zang
authors.affiliation: Research Center for Marine Ecology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China.
authors.forename: Chenying
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Bochao
authors.initials: B
authors.lastname: Xu
authors.affiliation: Research Center for Marine Ecology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China.
authors.forename: Jingxi
authors.initials: J
authors.lastname: Li
authors.affiliation: Research Center for Marine Ecology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China; Department of Earth Sciences-Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht 3508 TA, The Netherlands. Electronic address: rxb@fio.org.cn.
authors.forename: Xiangbin
authors.initials: X
authors.lastname: Ran
mesh_terms: D061006:Bays / Q000737:chemistry*; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010710:Phosphates; D014874:Water Pollutants, Chemical; D010758:Phosphorus
keywords: Diffusive flux; Low-oxygen; Phosphorus; Speciation; Transformation