西北太平洋低纬度区域海水中溶解氨基酸的分布及组成研究

Distribution and composition of dissolved amino acids in seawater of low-latitude Northwest Pacific

本文对2018年秋季西北太平洋低纬度区域上层海洋(5~200 m)中溶解氨基酸(THAA)的分布和组成进行了研究。结果表明,该海域表层海水中THAA的浓度范围为0.40~0.97μmol/L,平均浓度为0.58±0.14μmol/L;5~200m垂直断面上THAA的平均浓度为0.59±0.16μmol/L,范围为0.30~1.05μmol/L。调查海域内THAA浓度明显低于中国近海,在5~200m内的垂直分布基本表现出随深度增加而增加的趋势。将表层和垂直水体中的THAA分别与DOC、Chla等环境因子进行相关性分析,结果显示均无显著相关性。西北太平洋低纬度区域海水中的优势氨基酸是天冬氨酸(Asp)、谷氨酸(Glu)、丝氨酸(Ser)、甘氨酸(Gly)、苏氨酸(Thr)和丙氨酸(Ala)。基于氨基酸的碳归一化产率(THAA-C%)、降解因子(DI)值,表明该海域表层海水中的有机质降解程度较高,且随深度的增加而降低。

The distribution and composition of dissolved amino acids(THAA)were investigated in the upper seawater of the low-latitude Northwest Pacific Ocean in autumn 2018.Results showed that the concentration of THAA in the surface seawater ranged from 0.40 to 0.97μmol/L,with an average of 0.58±0.14μmol/L,while the average concentration of THAA in the vertical transect was 0.59±0.16μmol/L,ranging from 0.30 to 1.05μmol/L.The THAA concentration in the surveyed area was significantly lower than that in China’s offshore waters,and the vertical distribution of THAA within 5~200 m basically shows an increasing trend with increasing depth.Correlation analysis showed that THAA had no significant correlation with dissolved organic carbon,chl a,and other environmental parameters.The dominant amino acids in the seawater were aspartic acid,glutamic acid,serine,glycine,threonine,and alanine.Amino acid-based degradation indicators(THAA-C%,DI)showed that the degradation of organic matter in the surface seawater was high and decreased with increasing depth.