珠江首次禁渔西江段鱼类资源声学跟踪监测分析

2011年珠江开始实行禁渔期制度。该研究采用 Simrad EY60鱼探仪，分别于2010年5月19日和2011年5月22日对珠江西江段进行了走航式探测。结果显示，珠江禁渔期期间西江段鱼类资源密度增加，2010年和2011年鱼类平均密度分别为0.0513尾·m -3和0.1068尾·m -3，根据渔获物调查数据，推算增幅分别为广东鲂（Megalo-brama terminalis）47.85％、赤眼鳟（Squaliobarbus curriculus）18.54％、鲮（Cirrhina moitorella）10.87％和鳊（Parabra-mis pekinensis）6.25％；两年西江段深水区域鱼类密度均较大，尤其是水底结构为凹形区域，鱼类有明显的聚集现象；浅水区域且底部较平整的水域，鱼类分布分散且密度较低；垂直分布方面，鱼类主要分布4--10 m 中下层水层。珠江禁渔期的实施，在一定程度上保护了鱼类的产卵亲体繁殖，对鱼类资源数量的补充起到了增殖作用，同时在很大程度上护养了鱼类的自然生长，起到了资源增重作用。

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

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·m - 3 and 0. 106 8 ind·m - 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.