清河水库鲢鳙鱼类资源声学评估——回波计数与回波积分法的比较

2009年7月下旬使用挪威Simrad公司EY60型（70kHz）分裂式波束科学鱼探仪对清河水库进行了鲢（Hypophthalmichthys molitrix）和鳙（Aristichthys nobilis）的资源声学调查。使用声学处理软件Echoview4.0进行声学回波数据的后处理,研究库区内鲢和鳙昼夜分布特性,尝试使用回波计数法与回波积分法进行资源密度的评估,并进行了对比分析,讨论适合于水库鲢和鳙的声学调查方法。结果表明,鲢和鳙分布于水库10m附近水层,昼间较为集中,单体回波较少,夜间较为分散,可以识别的单体回波较多。深水区域个体较大且密度较低,较浅的区域个体较小且密度较大。声学计数评估更适合夜间进行。根据夜间数据,2种评估方法的结果基本一致,回波积分法获得鱼类密度为0.063ind.m-3,回波计数法为0.049ind.m-3,可以确定2种方法均适合鲢和鳙的调查。

Acoustic assessment of silver carp and bighead carp in Qinghe Reservoir:comparing echo-counting and echo-integrating methods

We conducted an acoustic assessment of silver carp（Hypophthalmichthys molitrix）and bighead carp（Aristichthys nobilis）resources in Qinghe Reservoir in late July of 2009 by using the Simrad EY60 split-beam echosounder.With the software Echoview 4.0,we post-processed the data to analyze the distribution of the species during day and night.Besides,we assessed the resource density by using echo-counting and echo-integrating methods,which were then compared to find out the suitable acoustic investigation method for the two species.The results show that both species gather around 10 m in the reservoir and gather more usually during the day with less single echo but disperse at night with more single echo.Large fish gather in deep water area with relative lower density but small fish in shallow water area with high density.The echo-counting method is more suitable for night assessment,and according to the night data,the estimated density is 0.063 ind·m-3 and 0.049 ind·m-3 obtained by echo-integrating and echo-counting methods,respectively.