红水河岩滩水库鱼类资源声学评估

为评估梯级开发下渔业资源变化情况,2015年9月采用分裂波束鱼探仪EY60(120 kHz,250 W)对红水河岩滩水库库区及上游江段鱼类资源进行声学调查,并结合渔获物统计和地理统计分析对鱼类时空分布进行分析,评估鱼类资源量。结果显示整个调查区域的鱼类资源密度为(0.53±2.11)尾·m~(-2)(±SD),从水坝上游至库区呈增长趋势,鱼类资源密度水平分布与水深无显著相关关系。垂直分布方面,鱼类主要分布在30 m以内水层;不同大小个体对水深有一定的选择性,小个体鱼类(10 cm)约86.2%分布在30 m水层之内;大个体(30 cm)有44.7%分布在40 m以下水层。基于鱼类分布GIS建模,估算调查区域鱼类资源量为6.57×10~7尾。

Acoustic survey of fish resources in Yantan Reservoir in the Red River

To assess the variation of fish resources caused by cascade development,we used a split-beam echosounder (120 kHz,250 W) with catch statistics and a geographic analysis to investigate the spatiotemporal variation and to estimate the existing resource abundance in Yantan Reservoir in the Red River in September,2015. The average fish resources density was (0.53±2.11) ind·m-2 with an increasing trend from upper to the Reservoir. The density distribution of fish resources had no significant correlation with water depth. The fish mainly distributed at 0~20 m layer. For water depth,individuals at different sizes had definite selectivity (86.2%):small fish (<10 cm) distributed within the 30 m layer and about 44.7% large fish (>30 cm) distributed at water layer deeper than 40 m. Based on the GIS fish distribution model,the fish resources abundance was about 6.57×107individuals.