Field Investigation on River Hydrochemical Characteristics and Larval and Juvenile Fish in the Source Region of the Yangtze River

Zhao Zhao,Xu Xu,Lin Lin,Li Li,Guo Guo,Gong Gong,Tang Tang

doi:10.3390/w11071342

Abstract

The source region of the Yangtze River (SRYR) is located in the Qinghai-Tibet Plateau, where the climatic conditions and alpine-cold natural conditions are harsh. Field investigations of the hydrochemical characteristics and larva and juvenile fish in rivers of the SRYR were carried out in July 2018 with the aim of obtaining further information on the unique ecological environment status of this plateau area. The results of the present research indicated that majority of the river water quality parameters in the SRYR were in the range of class I to class II, according to the classification of the environmental quality standard for surface water (GB3838-2002) in China. Among 12 kinds of metal ions, the concentrations of four major ions occurred in the following order: Ca > Na > Mg > K. The concentrations of eight heavy metal ions (Fe, Mn, Cu, Zn, Pb, Cd, Cr and As) were all within the class I water range based on GB3838-2002. A total of three species of larval and juvenile fish, i.e., Triplophysa stenura (T. stenura), Schizopygopsis microcephalus Herzenstein (S. microcephalus) and Triplophysa bleekeri (T. bleekeri), were collected from 11 sampling sites. It was found that T. stenura covered the widest distribution range and was the most abundant. The results of principal component analysis and canonical correspondence analysis demonstrated that the distribution of S. microcephalus exhibited a positive response to water temperature, a positive response to K and a negative correlation with water temperature were demonstrated in the distribution of T. stenura. T. bleekeri distribution had a positive response to Cu, but negative responses to total phosphorus and total dissolved solid.

Highlights

The Yangtze River (Changjiang) is the largest river in Asia and the third largest river in the world in terms of length (6300 km) and discharge (900 km3 /year), which rises from the Qinghai-Tibetan Plateau in the west and crosses the China through 11 provinces [1,2]
The source region of the Yangtze River (SRYR) is located between 90◦ 430 –96◦ 450 E and 32◦ 300 –35◦ 350 N, and has an average altitude of more than 4000 meters and an area of 12.24 × 104 km2 ; its area accounts for 43.6% of the total area of the Three-river Headwater Region, which is the source of the Yangtze, Yellow and Lancang Rivers in China and 8% of the total area of the Yangtze River
The SRYR is an important area in the Qinghai-Tibet Plateau; its main function is to ensure the long history of the Yangtze River and to transport water resources in high quality to the downstream [3,4]

Summary

Introduction

The Yangtze River (Changjiang) is the largest river in Asia and the third largest river in the world in terms of length (6300 km) and discharge (900 km3 /year), which rises from the Qinghai-Tibetan Plateau in the west and crosses the China through 11 provinces [1,2]. The source region of the Yangtze River (SRYR) is located in the hinterland of the Qinghai-Tibet Plateau, which is called the roof of the world, is well known as the “water tower of China” [3,4,5]. The SRYR is an important area in the Qinghai-Tibet Plateau; its main function is to ensure the long history of the Yangtze River and to transport water resources in high quality to the downstream [3,4]. The SRYR plays an important role in regulating the water volume and climate in the downstream due to its important ecological functions, such as water resources conservation and regulation, biodiversity conservation and ensuring the eco-security of the Yangtze River basin, which occupies an important position in the role of ecological security in China and even in Southeast Asia [6,7]

Methods

Results

Discussion

Conclusion