厦门大学海洋与地球学院

College of Ocean and Earth Sciences
教师后台登录
学院办公系统
研究生座位申请
实验教学中心
学院校友网
教室查看/预约
学院简介/年报
科考船简报
海洋科技博物馆
[午餐交流会] 第七十六讲:The level of phosphate controls decomposition rate of labile organic matter in hypoxic coastal waters
2017/6/27 223 返回上页
2017-7-3 (星期一) 11:40-12:00(领取午餐) 12:00-13:00(讲座)
刘占飞,副教授
周隆泉楼A3-206

【来访单位 Institution】:德克萨斯大学奥斯汀分校,美国    The University of Texas at Austin, USA

【邀请人 Host】:李骁麟  Xiaolin Li      【联络人 Contact】:刘辉   Angela Liu

Abstract

Despite extensive studies of the development and dynamics of hypoxia in coastal oceans, factors controlling the decomposition rates and pathways of labile organic matter (OM) in hypoxic waters are not well understood. We investigated peptide decomposition in a stratified water column in the hypoxic region of the northern Gulf of Mexico by conducting on-deck incubation experiments.  Our results showed that peptide decomposition efficiency was limited by the availability of soluble reactive phosphorus (Pi) in the surface water (<0.3 µM), as it was greatly enhanced after Pi addition to the incubation water. In contrast, peptide decomposition rate in the subsurface water, enriched with Pi (0.4-1.2 µM), was twice as high as that in the surface water, concomitant with the development of fast-growing bacteria during the incubation. These results indicate that a high level of Pi is crucial in stimulating the growth of bacterial strains with high RNA contents and thus faster OM decomposition, a positive feedback on hypoxia formation in Pi-enriched coastal subsurface waters. These results also offer insights into organic matter decomposition mechanism in deep open ocean enriched with nutrients.