Acoustic monitoring on fish resources in Xijiang section of Pearl River during first closed fishing season

• Published in: Nanfang shuichan kexue Vol. 10; no. 3; pp. 24 - 28
• Main Authors: WU, Zhi, TAN, Xichang, LI, Xinhui, TANG, Yong
• Format: Journal Article
• Language: English
• Published: 01.06.2014
• Subjects: Freshwater; Megalobrama terminalis; Parabramis pekinensis; Squaliobarbus curriculus; China, People's Rep., Zhu R
• ISSN: 2095-0780
• DOI: 10.3969/j.issn.2095-0780.2014.03.004

Closed fishing season was initially implemented in Pearl River in 2011. We used a Simrad EY60 echo-sounder with 120 kHz split-beam transducer to survey the Xijiang section of Pearl River. The results show that during the closed season, the density of fish resources was increasing, and the average fish densities were 0.051 3 ind times m super(-3) and 0.106 8 ind times m super(-3) in 2010 and 2011, respectively. According to the data of catches, the increases were deduced as follows; Megalobrama terminalis 47.85%, Squaliobarbus curriculus 18.54%, Cirrhina moitorella 10.87% and Parabramis pekinensis 6.25%. The deep water had higher fish density than shallow water, especially that fish obviously aggregated in concave region. The fish mainly distributed at depth of 4 - 10 m. The implementation of closed fishing season, to some extent, protects breeding of spawning stocks and supplements fish resources as well as maintenances natural growth of fishes.