Consistent increase in dimethyl sulfide (DMS) in response to high CO2 in five shipboard bioassays from contrasting NW European waters
Consistent increase in dimethyl sulfide (DMS) in response to high CO2 in five shipboard bioassays from contrasting NW European waters
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DOI：
10.5194/bg-11-4925-2014
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发表时间：
2014-01-01
期刊：
影响因子：
4.9
通讯作者：
Archer, S. D.
中科院分区：
文献类型：
--
作者：
Hopkins, F. E.;Archer, S. D.
无处不在的海洋微量气体二甲基硫化物（DMS）是大气中硫的最大天然来源，在大气化学和气候中起着关键作用。在5个96小时的船上生物测定实验中，研究了DMS的生产和循环及其藻类前体二甲基磺丙酸二甲酯（DMSP）对二氧化碳（CO2）升高和海洋酸化（OA）的短期响应。实验于2011年6月和7月进行，使用从欧洲西北部水域（外赫布里底群岛、爱尔兰海、比斯开湾、北海）不同地点收集的水。在环境CO2和三种高CO2处理（550、750、1000亩）的所有实验中，测定了DMS和DMSP的浓度、DMSP的合成速度、DMS的生产和消耗速度。总体而言，该地区对OA的响应变化不大，尽管包含了一系列生物和生物地球化学条件。我们观察到，相对于环境对照，DMS浓度持续且显著地增加(550亩地压下110%(28- 223%)，750亩地压下153%(56295%)，1000亩地压下225% (79- 413%))，DMSP浓度下降(550亩地压下28%(18- 40%)，750亩地压下44%（18- 64%)，1000亩地压下52%(2472%)）。在两个实验中，DMSP合成速率常数（mu DMSP, d(-1)）和DMSP生产速率（nmol d-1）显著降低（降低7-90%），而其余实验在高CO2下的反应与环境控制基本没有区别。细菌DMS总消耗量和产量对高CO2的响应弱且不一致。我们报告的变量和比率增加了我们对OA响应背后的过程的理解。这可以提供机会来改进中宇宙学衍生的经验模型关系，并朝着预测未来DMS浓度的机制方法迈进。
The ubiquitous marine trace gas dimethyl sulfide (DMS) comprises the greatest natural source of sulfur to the atmosphere and is a key player in atmospheric chemistry and climate. We explore the short-term response of DMS production and cycling and that of its algal precursor dimethyl sulfoniopropionate (DMSP) to elevated carbon dioxide (CO2) and ocean acidification (OA) in five 96 h shipboard bioassay experiments. Experiments were performed in June and July 2011, using water collected from contrasting sites in NW European waters (Outer Hebrides, Irish Sea, Bay of Biscay, North Sea). Concentrations of DMS and DMSP, alongside rates of DMSP synthesis and DMS production and consumption, were determined during all experiments for ambient CO2 and three high-CO2 treatments (550, 750, 1000 mu atm). In general, the response to OA throughout this region showed little variation, despite encompassing a range of biological and biogeochemical conditions. We observed consistent and marked increases in DMS concentrations relative to ambient controls (110% (28-223 %) at 550 mu atm, 153% (56295 %) at 750 mu atm and 225% (79-413 %) at 1000 mu atm), and decreases in DMSP concentrations (28% (18-40 %) at 550 mu atm, 44% (18-64 %) at 750 mu atm and 52% (2472 %) at 1000 mu atm). Significant decreases in DMSP synthesis rate constants (mu DMSP, d(-1)) and DMSP production rates (nmol d-1) were observed in two experiments (7-90% decrease), whilst the response under high CO2 from the remaining experiments was generally indistinguishable from ambient controls. Rates of bacterial DMS gross consumption and production gave weak and inconsistent responses to high CO2. The variables and rates we report increase our understanding of the processes behind the response to OA. This could provide the opportunity to improve upon mesocosm-derived empirical modelling relationships and to move towards a mechanistic approach for predicting future DMS concentrations.