| 摘要: |
| 2021年3月对长江口及其邻近海域9个断面溶解氨基酸(THAA)、溶解有机碳(DOC)和溶解有机氮(DON)的分布和组成进行了调查研究。结果表明:THAA的浓度范围为1.24~4.71μmol/L,平均浓度为(2.61±0.85)μmol/L;DOC的浓度范围为118.17~450.58μmol/L,平均浓度为(149.73±33.34)μmol/L;DON的浓度范围为10.48~24.45μmol/L,平均浓度为(13.80±1.81)μmol/L。THAA、DOC和DON的水平分布表现出近岸高于远岸的特点,表明陆源输入对调查区域的THAA等分布有重要影响。而THAA与D-天门冬氨酸、D-谷氨酸、D-丝氨酸和D-丙氨酸的D/L比均呈显著负相关,与天门冬氨酸/β-丙氨酸(Asp/β-Ala)呈正相关,表明细菌活动是影响THAA浓度变化的重要因素。长江口及邻近海域的优势氨基酸为L型氨基酸,D型氨基酸和非蛋白型氨基酸的占比仅为7.34%。基于C/N比值分析,长江口及其邻近海域溶解有机物(DOM)的来源受到长江冲淡水和台湾暖流的共同影响。THAA-C%、THAA-N%、降解因子和反应活性指数表明:水平方向上盐度接近于0的淡水区域和盐度高于34的远海区域降解程度较高;垂直方向上随着深度的增加,有机物的降解程度逐渐升高。调查区域有机物的降解程度主要受到陆源输入和细菌活动的影响。 |
| 关键词: 溶解态氨基酸 溶解有机碳 溶解有机氮 细菌降解 长江口 |
| DOI：10.11759/hykx20220206001 |
| 分类号: |
| 基金项目:山东省自然科学基金项目(ZR2020MD075);国家自然科学基金项目(41976038);中国科学院海洋生态与环境科学重点实验室(中国科学院海洋研究所)开放基金项目(KLMEES202001) |
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| Distribution, composition, and degradation behavior of dissolved organic matter in the Changjiang River Estuary and its surrounding area in spring |
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CHEN Bo-yang1, CHEN Rong1, CHEN Yan1, YANG Gui-peng1,2
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1.College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China;2.Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology(Qingdao), Qingdao 266237, China
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| Abstract: |
| The composition of dissolved amino acids (THAA), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) were determined in nine transections of the Changjiang River Estuary and its adjacent area in March 2021. The results demonstrated that the concentrations of THAA ranged from 1.24 to 4.71 μmol/L, with an average of (2.61±0.85) μmol/L; the concentrations of DOC ranged from 118.17 to 450.58 μmol/L, with an average of (149.73±33.34) μmol/L; the concentrations of DON varied from 10.48 to 24.45 μmol/L, with an average of (13.80±1.81) μmol/L. The concentrations of THAA were higher on the near shore than offshore, indicating that terrestrial input had a significant influence on the THAA distribution. THAA was negatively correlated with the D/L ratio of four D-amino acids (D-Asp, D-Glu, D-Ser, and D-Ala) and positively correlated with Asp/β-Ala ratios, suggesting that bacterial activity was an important factor in regulating the THAA concentration change. The dominant amino acids in the seawater were L-amino acids. The proportion of D-amino acids and non-protein amino acids was 7.34%. The C/N ratio is an effective factor in indicating the source of organic matter. The C/N ratio indicated that the source of dissolved organic matter in the study area was affected by the Changjiang Diluted Water and Taiwan Warm Current. THAA-C%, THAA-N%, degradation factor and reactivity index illustrated that the degradation degree was higher at stations with salinity near zero and offshore stations with salinity over 34. On a vertical scale, the degradation degree of organic matter increased gradually with the increase of depth. The degradation degree of organic matter in the survey area was mainly affected by terrestrial input and bacterial activity. |
| Key words: dissolved amino acid dissolved organic carbon dissolved organic nitrogen bacterial degradation Changjiang River Esturay |
