Molecular and Isotopic Coupling between Pelagic and Benthic Carbon Cycling-a Proof of Concept

远洋和底栖碳循环之间的分子和同位素耦合——概念证明

• 批准号: 9911678
• 负责人: Stuart Wakeham
• 金额: --
• 依托单位: Skidaway Institute of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-15 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9911678&HistoricalAwards=false
• 关键词: Molecular; Isotopic; Coupling; between; Pelagic

ABSTRACTOCE-9911678The quantitative relationship between organic matter falling through the water column and that accumulating in seafloor sediments presents one of the major challenges to understanding the organic chemistry of the ocean. Although organic matter produced biologically in the upper ocean transfers a marine chemical signature to the sediments, the organic matter in surface sediments looks very different: it is compositionally different, apparently enriched with terrestrial biomarkers and having radiocarbon ages suggesting input of old reworked material. In this study, scientists at the Skidaway Institute of Oceanography will use paired samples of organic matter collected in sediment traps and underlying sediments to deduce the chemical character of the organic matter that is degraded (and thus removed) from sinking organic matter before it accumulates on the seafloor. First, they will determine the molecular and isotopic character of key biomarkers in sediment trap/sediment pairs from a variety of oceanic environments. Secondly, they will use molecular and isotopic distributions to constrain the character of the bulk of organic carbon that is degraded in the water column and at the sediment-water interface, the loss of which determines the nature of the organic carbon that can be accumulated in sediments and preserved in the sedimentary record.

Abstractoce-9911678有机物通过水柱落下的有机物之间的定量关系，在海底沉积物中积累的有机物是理解海洋有机化学的主要挑战之一。尽管在上海上生物学产生的有机物将海洋化学签名转移到沉积物中，但表面沉积物中的有机物看起来截然不同：构图上不同，显然富含陆地生物标志物，并具有放射性碳年龄，暗示了旧重制材料的输入。在这项研究中，Skidaway海洋学研究所的科学家将使用在沉积物陷阱和潜在的沉积物中收集的有机物样品来推断有机物的化学特征，这些化学特征在降低有机物之前被降解（并从中取出），然后再在海藻上积聚。首先，他们将确定来自各种海洋环境中的沉积物陷阱/沉积物对中关键生物标志物的分子和同位素特征。其次，他们将使用分子和同位素分布来限制水柱和沉积物 - 水界面中降解的大部分有机碳的特征，这些损失决定了可以积聚在沉积物中并保存在沉积记录中的有机碳的性质。