三峡水库175m蓄水前鱼类分布特征研究

为了解三峡库区175 m蓄水前鱼类资源量及其分布特点,于2009年12月和2010年4月利用SIMRADEY60鱼探仪对三峡库区秭归至重庆江段进行了声学调查。结果表明:鱼类在秭归至重庆段分布不均匀,12月份密度最大区域为万州——丰都,最大密度为1 347.3 ind./km3,4月份鱼类集中在长寿——重庆江段,最大密度为864.4 ind./km3,并且冬季整个江段鱼类密度平均值明显大于春季的平均值。垂直方向上,不管是在冬季还是在春季,下层的鱼类密度始终最大,并且各层鱼类密度的差异冬季比春季更为明显。三峡库区175 m蓄水前鱼类的分布特征和水位、水流、地形等因素密切相关。

Study on the fish distribution characteristic of the Three Gorges Reservoir before 175 m

In order to realize the fishery resource and its distribution characteristics before impoundment at the water level of 175m,the section from Zigui to Chongqing at the Three Gorges Reservoir was investigated by a split-beam echosounder SIMRAD EY60.The result showed that fish distribution in horizontal direction was uneven.In winter,fishes preferred to inhabit at the section from Wanzhou to Fengdu,and the highest density was 1 347.3 ind./km3.In spring,fish density at the section from Changshou to Chongqing was the highest and the value was 864.4 ind./km3.In addition,the average fish density in winter was obvious ly higher than in spring.In vertical direction,fish density in the lower layer was the highest either in winter or in spring and the difference of each layer in winter was more obvious than in spring.The fish distribution characteristics before 175m were related to many factors such as water level,water flow,terrain and so on.