秋季东海二甲基有机硫化物的浓度分布与影响因素

于2012年10月对中国东海表层海水中二甲基硫（DMS）及其前体物质二甲巯基丙酸内盐（DMSP）、溶解自由态蛋氨酸（DF Met）的浓度分布及影响因素进行了研究。分析结果表明，秋季东海表层海水中硅酸盐（SiO₃-Si）、溶解无机氮（DIN）、磷酸盐（PO₄-P）浓度变化范围分别为0.11~1.76、0.08~0.56和0.013~0.054 mg/L，平均值为0.50±0.36、0.19±0.11和0.024±0.0098 mg/L，且东海西南部上升流区出现营养盐浓度的高值区。表层海水中DMS、DMSP和DF Met的浓度分别在0.47~6.46、9.44~55.57和3.48~14.42 nmol/L之间，平均值分别为3.10±1.93、28.05±14.17和6.19±2.30 nmol/L。DMS、DMSP的水平分布与叶绿素a（Chl a）分布基本一致，呈现出近岸向远海降低的趋势。所调查海域的DMS/Chl a和DMSP/Chl a比值变化范围分别为2.59~27.66和27.37~103.34 mmol/g，平均值分别为11.46±5.02和65.08±23.41 mmol/g，与该海域硅藻为浮游植物优势种的调查结果相一致。此外，秋季东海表层海水DMS的海-气通量介于0.89~105.50 μmol/（m2·d）之间，平均值为35.65 ±31.53 μmol/（m2·d）。

Distributions of organic dimethylated sulfur compounds and its influencing factors in the East China Sea during autumn

The distributions of concentrations of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dissolved free methionine (Met) and their control factors were studied in surface water of the East China Sea (ECS) during October 2012.The concentrations of silicate (SiO₃-Si), dissolved inorganic nitrogen (DIN) and phosphate (PO₄-P) ranged from 0.11 to 1.76, 0.08 to 0.56 and 0.013 to 0.054 mg/L, respectively, with the average values of 0.50±0.36, 0.19±0.11 and 0.024±0.0098 mg/L.Higher concentration of nutrients appeared in the upwelling region of the southwest ECS.The concentrations of DMS, DMSP and Met ranged from 0.47 to 6.46 nmol/L, 9.44 to 54.57 nmol/L and 3.48 to 14.42 nmol/L, respectively, with the average values of 3.10 ± 1.93, 28.05 ± 14.17 and 6.19 ± 2.30 nmol/L.The horizontal distributions of DMS and DMSP have decreased trend from inshore to offshore, with the silimar pattern as chlorophyll a (Chl a).The ratios of DMS/Chl a and DMSP/Chl a in the water column ranged from 2.59 to 27.66 mmol/g and from 27.37 to 103.34 mmol/g, respectively, with average values of 11.46 ± 5.02 and 65.08 ± 23.41 mmol/g, which corresponded well with the dominant phytoplankton of the algae. Furthermore, the sea-to-air fluxes of DMS in autumn were from 0.89 to 105.50 μmol/(m2·d), with an average of (35.65 ± 31.53) μmol/(m2·d).