Study on Dimethylsulfide production by phytoplankton based on time-serial observations in the Antarctic Ocean

基于南极海域浮游植物产生二甲硫醚的时间序列观测研究

基本信息

批准号：
14405038
负责人：
ODATE Tsuneo
金额：
$ 9.28万
依托单位：
National Institute of Polar Research
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

Dimethylsulfide (DMS) is the most abundant form of volatile sulfur in the ocean. According to the CLAW hypothesis (Charlson et al. 1987), marine DMS production may act as a climate regulatory mechanism via a feedback loop involving surface ocean temperature, phytoplankton, DMS, sulfate aerosol formation, and cloud albedo, although the existence of this feedback has not been proven. Recently, attention has been focused on assessing sinks and sources of DMS in the oceans and on the processes controlling the cycling of DMS in the marine environment. DMS is produced by the enzymatic cleavage of dimethylsulfoniopropionate (DMSP), an organic compound synthesized by many phytoplankton species. The objective of this study was to determine the influence of biological processes on DMS dynamics in the Antarctic Ocean during the summertime, based on the time-serial observations in the austral summers of 2002/03, 2003/04, and 2004/05. The field data collected in the present study was synthesized in 2005. The present results show that sloppy feeding by Antarctic krill, which is the dominant herbivorousis macrozooplankton of the Antarctic Ocean, a more likely mechanism for producing DMS and dissolved DMSP. Moreover growth phase seems to be related DMSP production by diatoms. This may result in the low concentrations of dissolved DMSP observed in the early stage of diatom blooms under natural conditions. Since these processes on biological production as well as DMS and DMSP production are seem to be affected by variations of sea ice distribution, further study must be required to fully understand the global environment change.

二甲硫醚（DMS）是海洋中最丰富的挥发性硫。根据 CLAW 假说（Charlson 等，1987），海洋 DMS 的产生可能通过涉及海洋表面温度、浮游植物、DMS、硫酸盐气溶胶形成和云反照率的反馈回路充当气候调节机制，尽管这种反馈的存在尚未被证明。最近，人们的注意力集中在评估海洋中 DMS 的汇和来源以及控制海洋环境中 DMS 循环的过程上。 DMS 是通过二甲基磺酰基丙酸酯 (DMSP) 的酶裂解产生的，DMSP 是一种由许多浮游植物物种合成的有机化合物。本研究的目的是根据 2002/03、2003/04 和 2004/05 年南方夏季的时间序列观测，确定夏季生物过程对南极海洋 DMS 动态的影响。本研究收集的现场数据于 2005 年综合。目前的结果表明，南极磷虾（南极海洋的主要草食性大型浮游动物）的草率摄食，更可能是产生 DMS 和溶解的 DMSP 的机制。此外，生长阶段似乎与硅藻产生 DMSP 有关。这可能导致在自然条件下硅藻华早期观察到溶解的 DMSP 浓度较低。由于这些生物生产过程以及DMS和DMSP生产似乎受到海冰分布变化的影响，因此需要进一步研究以充分了解全球环境变化。