Gao Xin, Lin Pengcheng, Li Mingzheng, Duan Zhonghua, Liu Huanzhang
The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy Of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, 7th Southern Road of East Lake, Wuhan, Hubei Province 430072, P.R. China.
Zoolog Sci. 2014 May;31(5):274-8. doi: 10.2108/zs130123.
Chinese sturgeon, Acipenser sinensis, is a critically endangered anadromous fish species spawning in the Yangtze River of China during October and November. In this study, we analyzed the effects of hydrological factors, such as water temperature and discharge, on the natural reproduction time of the Chinese sturgeon and evaluated the impact of the impoundment of the Three Gorges Reservoir (TGR) based on our survey data from 1998 to 2011. The results showed that the first spawning dates were significantly (P < 0.05) correlated with the date of water temperature reaching 20°C (20°C WT dates), October mean discharge (Oct. discharge), and the discharge change from October to November (Oct-Nov Δdischarge). Regression analysis suggested that one day delay of 20°C WT dates could postpone the first spawning date by 0.673 days. A discharge increase of 1000 m(3)s(-1) in October could bring forward the first spawning date by two days. Our results also indicated that the impoundment of the TGR had delayed the first spawning time due to water temperature lag and flow regulation. We suggest the following ecological regulations in order to facilitate conservation of the Chinese sturgeon: to eliminate water temperature lag by regulating water temperature downstream of the Three Gorges Dam (TGD), to enhance water discharge downstream in October, and to complete impoundment before October.
中华鲟，学名Acipenser sinensis，是一种极度濒危的溯河产卵鱼类，于每年10月至11月在中国长江产卵。在本研究中，我们分析了水温、流量等水文因素对中华鲟自然繁殖时间的影响，并根据1998年至2011年的调查数据评估了三峡水库蓄水的影响。结果表明，首次产卵日期与水温达到20°C的日期（20°C水温日期）、10月平均流量（10月流量）以及10月至11月的流量变化（10 - 11月流量变化）显著相关（P < 0.05）。回归分析表明，20°C水温日期每延迟一天，首次产卵日期将推迟0.673天。10月流量增加1000立方米/秒可使首次产卵日期提前两天。我们的结果还表明，三峡水库的蓄水由于水温滞后和流量调节而推迟了首次产卵时间。为了促进中华鲟的保护，我们建议采取以下生态调控措施：通过调节三峡大坝下游的水温消除水温滞后，在10月增加下游的流量，并在10月前完成蓄水。
