三峡水库生态调度对长江监利江段四大家鱼早期资源的影响

为探究生态调度对长江中游四大家鱼繁殖的影响,并了解影响家鱼产卵的关键生态水文指标的量化范围,于2013—2017年5—7月三峡水库生态调度期间在长江中游监利江段进行了鱼类早期资源调查,同时对采集到的四大家鱼卵苗与生态水文指标进行了相关性分析。结果显示,家鱼卵苗量与流量增长率呈显著正相关。每年6月下旬的生态调度,监利江段涨水持续时间为4 d及以上,流量增长率为1 600～2 833 m~3/(s·d)时,家鱼卵苗发生量较大,可占年总规模的45%以上。三峡水库生态调度涨水过程能够在一定程度上满足监利江段四大家鱼繁殖的水文需求,对减缓三峡水库运行引起的长江中游鱼类繁殖的不利影响和维持鱼类种群资源补充具有重要意义。

Effects of ecological operation of Three Gorges Reservoir on larval resources of the four major Chinese carps in Jianli section of the Yangtze River

In order to explore the effect of ecological operation of Three Gorges Reservoir on breeding of the four major Chinese carps in Jianli section of the Yangtze River, and evaluate the quantitative range of ecological hydrology indexes that stimulate spawning behavior of four major Chinese carps, in this study, we investigated the early life resources of the Four Major Chinese Carps in Jianli section of the middle reaches of the Yangtze River, from May to July, 2013-2017. Correlation analysis was made between the Four Major Chinese carps'' spawning and larvae collected and the ecological hydrology index. The results show that there is a significantly positive correlation between the daily flow increasing rate and the quantity of fish eggs. When the duration is 4 d and more, and the daily flow increasing rate is from 1 600 to 2 833m³/(s·d)], ecological operation is more effective to stimulate the reproduction of the Four Major Chinese Carps in late June. Preliminary results indicated, water rising of ecological operation of Three Gorges Reservoir has improved the hydrological conditions for the breeding of four major Chinese carps in Jianli section. The implement of ecological operation not only reduced the negative impact on fish breeding in the midstream of the Yangtze River, but also maintained fish population resources after the operation of the Three Gorges Reservoir.