Processes driving seasonal variability in DMS, DMSP, and DMSO concentrations and turnover in coastal Antarctic waters
Processes driving seasonal variability in DMS, DMSP, and DMSO concentrations and turnover in coastal Antarctic waters
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DOI：
10.1002/lno.10379
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发表时间：
2017-01-01
影响因子：
4.5
通讯作者：
Tortell, P. D.
中科院分区：
文献类型：
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作者：
Asher, E. C.;Dacey, J. W. H.;Tortell, P. D.
这项研究对2012-2013年春季和夏季南极帕尔默站附近近海水域中二甲基硫(DMS)、二甲基磺基丙酸酯(DMSP)和二甲基亚砜(DMSO)的浓度和周转速率进行了新的测量。利用几种新的分析和实验技术，我们记录了DMS、DMSP和DMSO(DMS/P/O)浓度的变异性，并量化了混合层DMS预算中的主要生产和去除项。结果表明，DMS浓度(范围0-20 nm)、总DMSP浓度(8-160 nm)和总DMSO浓度(4-160 nm)存在显著的季节变化。在季节周期中，溶解DMSP浓度与DMSP总浓度和南极棕囊藻丰度有很好的相关性，而DMSO浓度(总浓度和溶解浓度)与DMS浓度有很好的相关性。DMS的主要来源是溶解水池的DMSP分解(平均速率为5.5 nMd(-1))和小型浮游动物放牧释放的DMS(平均5.6 nMd(-1))，DMS的产生速率较小与DMSO的减少(平均2.6 nMd(-1))和磷虾放牧(平均0.82nmd(-1))有关。DMSP裂解的比速率常数与净初级生产力呈负相关。细菌摄取是DMS去除的主要贡献者(平均-12nmd(-1))，我们观察到细菌产量和DMS总损失速率常数之间存在显著的相关性。估计的海-气通量和光氧化作用构成了DMS的次生汇。我们的实验和分析方法提供了对帕尔默站DMS/P/O循环的洞察，并为未来研究南极沿海水域DMS/P/O年际变化提供了一个起点。
This study presents new measurements of the concentrations and turnover rates of dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP), and dimethyl sulfoxide (DMSO) in coastal waters near Palmer Station, Antarctica, during the spring and summer of 2012-2013. Using several novel analytical and experimental techniques, we document variability in DMS, DMSP, and DMSO (DMS/P/O) concentrations and quantify dominant production and removal terms in the mixed layer DMS budget. Our results demonstrate considerable seasonal variability in the concentration of DMS (range 0-20 nM), total DMSP (8-160 nM), and total DMSO (4-160 nM). Over the seasonal cycle, dissolved DMSP concentrations were well correlated with total DMSP concentrations and the abundance of Phaeocystis antarctica, while DMSO concentrations (total and dissolved) were well correlated with DMS concentrations. DMSP cleavage from the dissolved pool (mean rate=5.5 nM d(-1)) and release from microzooplankton grazing (mean 5.6 nM d(-1)) were the dominant sources of DMS, with smaller DMS production rates associated with DMSO reduction from the dissolved pool (mean 2.6 nM d(-1)) and krill grazing (mean 0.82 nM d(-1)). Specific rate constants for DMSP cleavage were inversely related to net primary production. Bacterial uptake was a primary contributor to DMS removal (mean -12 nM d(-1)), and we observed a significant correlation between bacterial production and gross DMS loss rate constants. Estimated sea-air flux and photo-oxidation constituted secondary DMS sinks. Our experimental and analytical methods provide insight into the DMS/P/O cycle at Palmer Station, and a starting point for future studies examining inter-annual DMS/P/O variability in coastal Antarctic waters.