Journal of Tropical Oceanography ›› 2021, Vol. 40 ›› Issue (5): 63-71.doi: 10.11978/2020107CSTR: 32234.14.2020107

• Marine Biology • Previous Articles     Next Articles

Distribution of Pearl-River diluted water and its ecological characteristics during spring monsoon transitional period in 2016*

SHUAI Yiping1,2(), CHEN Yinchao1,2, LIU Zijia1,2, GE Zaiming1,2, MA Mengzhen1,2, ZHANG Yuanfang1,2, LI Qian1,2,3()   

  1. 1. State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences), Guangzhou 510301, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
  • Received:2020-09-16 Revised:2021-01-13 Online:2021-09-10 Published:2021-01-07
  • Contact: LI Qian E-mail:shuaiyp@scsio.ac.cn;qianli@scsio.ac.cn
  • Supported by:
    National Key Research and Development Program of China(2016YFC0301202);National Key Research and Development Program of China(2016YFA0601203);National Natural Science Foundation of China(41676108);Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0305)

Abstract:

Based on in situ physical and biological observations and remote sensing data, we analyzed the distribution characteristics of wind, diluted water and its ecological response in the Pearl River Estuary (PRE) during the spring monsoon transitional period (April — June) in 2016. The results showed that non-unidirectional wind prevailed in the PRE and its adjacent area from April to May, and weak southwest monsoon prevailed in June. Meanwhile, the Pearl-River discharge flux increased over time. Influenced by wind and Pearl-River runoff, the diluted water expanded westward alongshore in April and offshore in May, with a maximum distance of more than 70 km away from the coast. The diluted water expanded both eastward and westward in June. The westward diluted water was restricted, and formed an estuarine front with significant salinity and turbidity gradient outside the mouth of the estuary when encountered the southerly monsoon and background currents. The estuarine front extended offshore and formed a large plume in eastward offshore regions. Furthermore, the distribution of fluorescent and oxygen were mainly influenced by diluted water and showed similar patterns. In the vertical direction, the process of hypoxia formation was observed in the PRE. Seawater stratification and the formation of stable water column together with biodegradation process jointly led to low dissolved oxygen at the bottom of the PRE. The distribution of turbidity was mainly influenced by suspended sediments carried by river discharge, and showed strong negative correlation with salinity.

Key words: Pearl River Estuary, spring transitional period of monsoon, diluted water, dissolved oxygen, turbidity

CLC Number: 

  • P735.121