热带海洋学报 ›› 2026, Vol. 45 ›› Issue (3): 61-73.doi: 10.11978/2025114CSTR: 32234.14.2025114

所属专题: 南海专题

• 海洋化学 • 上一篇    下一篇

南海表层水悬浮颗粒物脂肪酸组成特征及其生态指示意义*

李东平(), 石豪磊, 罗中原, 曹建涛, 贾国东()   

  1. 同济大学海洋与地球科学学院, 海洋地质全国重点实验室, 上海 200092
  • 收稿日期:2025-07-23 修回日期:2025-09-29 出版日期:2026-05-10 发布日期:2026-05-28
  • 通讯作者: 贾国东。 email: jiagd@tongji.edu.cn
  • 作者简介:

    李东平(1997—), 男, 辽宁省抚顺市人, 硕士研究生, 从事有机地球化学研究。email:

  • 基金资助:
    国家自然科学基金重点项目(42030504); 国家自然科学基金委员会共享航次计划项目(42249906)

Compositional characteristics and ecological significance of fatty acids of the surface suspended particulate matter in the South China Sea*

LI Dongping(), SHI Haolei, LUO Zhongyuan, CAO Jiantao, JIA Guodong()   

  1. State Key Laboratory of Marine Geology, School of Ocean and Earth Sciences, Tongji University, Shanghai 200092, China
  • Received:2025-07-23 Revised:2025-09-29 Online:2026-05-10 Published:2026-05-28
  • Contact: JIA Guodong. email: jiagd@tongji.edu.cn
  • Supported by:
    National Natural Science Foundation of China(42030504); National Natural Science Foundation of China Shared Cruise Project(42249906)

摘要:

脂肪酸是生物细胞膜的一类重要脂质成分, 具有较强的生物指示意义。但是, 海洋颗粒物中脂肪酸的组成如何有效反映颗粒有机质的来源及海洋浮游生物的群落结构特征等方面的研究并不多, 在南海尤其缺乏相关资料。本文对南海夏季表层悬浮颗粒物中的脂肪酸组成进行了详细分析, 共检出30种脂肪酸化合物。通过聚类分析把这些脂肪酸划分为新鲜浮游植物、浮游植物碎屑、细菌、浮游动物和陆源高等植物等五种不同来源。其中, 新鲜浮游植物脂肪酸主要为不饱和脂肪酸, 特别是多不饱和脂肪酸, 从中可分辨出硅藻、甲藻和蓝细菌等不同来源。对这些脂肪酸在南海的空间分布进行了系统分析, 结果表明, 南海西南及西部的夏季上升流影响区域以新鲜浮游植物, 特别是硅藻贡献的脂肪酸为主, 而处于东北部的高温高盐区域则以浮游植物碎屑贡献的短链饱和脂肪酸为主。浮游动物脂肪酸则分别对应于新鲜浮游植物脂肪酸和浮游植物碎屑脂肪酸而呈现出相应的高值。细菌脂肪酸与浮游植物不饱和脂肪酸大致呈反向分布格局, 反映出生态系统的初级生产与呼吸降解之间的相对变化: 在西南—西的方向上以初级生产为主导, 而在中部和东南方向上微生物的呼吸作用增强。陆源的长链饱和脂肪酸占比很低, 其分布呈现夏季海流驱动的模式, 自西南向东北方向减少。本研究表明, 脂肪酸作为分子生物标志物可有效指示南海表层水体颗粒物中不同生物源的输入情况, 对于揭示海洋浮游植物的群落结构特征具有潜在的应用价值。

关键词: 脂肪酸, 生物标志物, 表层水悬浮颗粒物, 浮游生物, 南海

Abstract:

Fatty acids, as key lipid components of membranes, hold significant value as bio-indicators. However, there are few studies on how the composition of fatty acids in marine particulate matter effectively reflects the source of organic matter and the community structure characteristics of marine plankton, particularly in the South China Sea (SCS). This study presents a detailed analysis of fatty acids in surface suspended particulate matter of the SCS during summer, identifying 30 fatty acid compounds. Based on statistical cluster analysis, these fatty acids are categorized into five sources: fresh phytoplankton, phytoplankton detritus, bacteria, zooplankton, and terrestrial higher plants. Fresh phytoplankton-produced unsaturated fatty acids, especially polyunsaturated fatty acids (PUFA), can be attributed to diatoms, dinoflagellates, and cyanobacteria. These fatty acids are relatively rich in the southwest and west regions of the SCS, affected by summer upwelling, indicating abundant fresh phytoplankton, particularly diatoms. In contrast, the northeastern region, with high temperature and salinity, is dominated by short-chain saturated fatty acids from phytoplankton detritus. Zooplankton fatty acids exhibit corresponding high levels in relation to fresh phytoplankton and phytoplankton detritus fatty acids. Bacterial fatty acids show an inverse distribution to phytoplankton unsaturated fatty acids, reflecting a shift between primary production and decomposition in the ecosystem: primary production is dominant in the southwest and west, while microbial respiration is more active in the central and southeast regions. Terrestrial long-chain fatty acids are minimal and follow a summer current-driven distribution pattern, decreasing from the southwest to the northeast. This study demonstrates that fatty acids, as effective molecular biomarkers, can effectively indicate the input of different biogenic sources to the SCS, demonstrating its potential value helpful in uncovering marine ecological structures over large spatial scale.

Key words: fatty acid, biomarker, sea surface suspended particulate matter, plankton, South China Sea

中图分类号: 

  • Q178