【摘要】 通过走航观测对南海–东印度洋海域的大气细颗粒物(PM_2.5)（共49个）进行采集,使用DAPI染色荧光显微技术获得微生物气溶胶浓度,开展微生物气溶胶在该海域空间分布特征的研究。结果显示,微生物气溶胶浓度范围在2.14×10⁴～5.93×10⁶ cells·m^-3之间,空间分布明显不均衡,即东印度洋>海峡>南海。在东印度洋海域,微生物气溶胶浓度变化幅度较大,以赤道为界,总体呈现北高南低的趋势。微生物气溶胶的粒径主要分布在0.37～2.5μm之间。南海、海峡和东印度洋赤道以北样品中原核生物占比较高,约65%;而在东印度洋赤道以南,真核生物占比则升高至近50%。最后,本研究根据东印度洋海域微生物气溶胶的差异,对其来源开展研究,揭示了海洋生物分布、海洋环境要素以及人为源远距离传输等因素对于开放海域微生物气溶胶浓度的影响。更多还原

【Abstract】 In this study, we collected 49 atmospheric PM_2.5 samples during a cruise campaign over the oceanic area from the South China Sea（SCS） to the Eastern Indian Ocean（EIO）, and obtained the microbial concentrations using fluorescence microscopy after staining with 4’,6-diamidino-2-phenylindole dihydrochloride（DAPI）. The microbial concentrations ranged from 2.14×10⁴ to 5.93×10⁶ cells·m^–3, showing a clear spatial distribution. The average concentration of microbial aerosols in the EIO was higher than those in the SCS and the three straits. In the EIO, the microbial concentrations varied greatly, showing higher concentrations in the northern region than in the southern region. Microbial aerosols dominated in the size range of 0.37 to 2.5 μm. The proportion of prokaryotes was relatively high（approximately 65%） in the SCS samples, the strait samples, and the northern EIO samples, whereas the proportion of eukaryotes in the southern EIO samples was higher. We therefore investigated the possible contributing sources and propose that marine biological distribution and marine environmental elements play important roles in the variation of microbial aerosol concentrations in the open ocean. We further suggest the importance of continental anthropogenic contributions to marine microbial aerosols via long-range transport in this oceanic area.更多还原