title: Process study of biogeochemical cycling of dissolved inorganic arsenic during spring phytoplankton bloom, southern Yellow Sea.
abstract: Previous studies in the southern Yellow Sea (SYS) suggest that large spring phytoplankton blooms (SPBs) have occurred in recent decades. Elevated primary production in the water column can lead to the accumulation and transformation of trace elements. Two field study cruises (including two drifting anchor surveys) were conducted on 12-19 February and from 24 March to 15 April 2009, to investigate the impact of different SPB development periods on the concentrations of total dissolved inorganic arsenic (TDIAs: [TDIAs]=[As(V)]+[As(III)]) and As(III) (arsenite) in the SYS. The distribution of TDIAs in the study area was similar between the two field studies, with concentrations increasing from coastal to offshore areas. High arsenite concentrations and As(III)/TDIAs ratios were found in areas having high concentrations of chlorophyll-a, particularly in the subsurface waters of the central SYS during the drifting surveys, where a significant SPB occurred. Results show that the integrated arsenite concentrations increased at an average transformation rate of 0.53±0.24nmol/L/d within the 15days during the bloom, and data from the anchor drifting surveys indicated that approximately 15.1% of the arsenate in the euphotic zone (~30m depth) was converted to arsenite. In addition, 7.1% of TDIAs was scavenged from the water column by phytoplankton forming the blooms (a factor of 5 higher than expected). A preliminary box model was established to estimate the budget for TDIAs in the SYS in early spring (February to April). This showed that biological scavenging is an important sink for TDIAs, which may promote the transformation and migration of inorganic arsenic species, and thus have a substantial impact on the biogeochemical cycling of this element in the SYS. Depletion of arsenate in the upper waters could lead to arsenate stress, potentially damaging fisheries and the ecosystem.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China. Electronic address: renjingl@ouc.edu.cn.
authors.forename: Jing-Ling
authors.initials: JL
authors.lastname: Ren
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China.
authors.forename: Xiu-Hong
authors.initials: XH
authors.lastname: Cao
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, PR China.
authors.forename: Su-Mei
authors.initials: SM
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, State Oceanic Administration, 36 Baochu North Road, Hangzhou 310012, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Hao
authors.affiliation: State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, State Oceanic Administration, 36 Baochu North Road, Hangzhou 310012, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 Zhongshan Road North, Shanghai 200062, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
mesh_terms: D001151:Arsenic / Q000032:analysis*; D002681:China; D017753:Ecosystem; D005068:Eutrophication; D009792:Oceans and Seas; D010839:Phytoplankton / Q000254:growth & development*; D012621:Seasons; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Arsenate; Arsenite; Chlorophyll-a; Diatoms; Dinoflagellates