Author(s): Lei Tang, Yu Qing Lin, Qiu Wen Chen, Wei Jiang, Yu Xin Zhang
Linked Author(s): Qiuwen Chen
Keywords: Four major Chinese carps, spawning behavior, fish egg quantity, flow velocity, velocity rise rate.
Abstract: The Three Gorges Reservoir is a key project in the middle reach of Yangtze River, impoundment of the reservoir has changed hydrological regime in downstream area, and also affected the natural reproduction of four major Chinese carps, leading to a deep recession in population. In this paper, a research about hydrodynamic spawning cues for four major Chinese carps was undertaken as follows: firstly, the amount of eggs of four major Chinese carps in the Yanzhiba spawning ground of the Yangtze River have been monitored daily during spawning seasons from 2012 to 2014. Then, flow conditions of the spawning ground at the monitoring periods were simulated through a two-dimension hydrodynamic model, which has been validated by measured hydrological data. Finally, relationships between the quantity of eggs of four major Chinese carps and flow conditions were compared. The results showed that both velocity and rise rate of velocity acted as crucial hydrodynamic factors, which obviously affected the spawning success by four major Chinese carps. Furthermore, the suitable velocity for stimulating spawning behavior was between 1. 31 to 1. 48 m/s, too small or too large velocity was not benefit for spawning success, the same suitable velocity rise rate for spawning appeared to range from 0. 013 to 0. 023 (m/s) /d. This paper could not only offer important basis to spawning ground restoration work of four major Chinese carps but also provide reasonable guidance for the eco-regulation of Three Gorges Reservoir
Year: 2017