葛洲坝1号船闸启闭闸门对近闸区域鱼类活动规律的影响

于2013年4月,在葛洲坝1号船闸下游闸首,利用双频识别声纳(DIDSON)对船闸不同运行状态下(关闸、放水、开闸)近闸区域的鱼类数量和密度进行了定点探测,并同步进行水质水动力现场监测,研究船闸启闭闸门对近闸区域鱼类活动规律的影响。研究结果表明:葛洲坝1号船闸在放水期间,对下游近闸区域流速及水体溶解氧(DO)浓度影响较大,对pH值及水温的影响不明显;鱼类密度与流速及DO呈显著相关性,与pH值及水温的变化相关性不显著;船闸在放水期间对近闸区域水体环境的改变,产生了诱导鱼类进入闸室下游出口的明显趋势。本研究为中低水头水利枢纽船闸与鱼道结合的可行性研究提供基础数据,同时也为鱼类行为学的研究提供参考依据。

Fish Assemblages under Different Running Status of the No.1 Ship Lock of the Gezhou Dam

Gezhou Dam blocks the migratory channel and fragments fish habitat, negatively affecting the fishery resource in the Yangtze River. The artificial breeding and releasing program in Yangtze River, although important, is not sufficient to maintain genetic diversity. The ship locks act as a biological channel connecting segments upstream and downstream of the Gezhou Dam and No. 1 ship lock has the best potential for fish passage. In this study, fish abundance and fish density were monitored while water was accumulating (gate closed) and while it was being discharged (gate open) in No.1 ship lock of Gezhou Dam. Fish monitoring was accomplished using double-frequency identification sonar (DIDSON) and other parameters including water velocity, temperature, dissolved oxygen (DO) and pH were measured near the ship lock with a multi-sensor water quality probe. The relationship between water quality, hydrodynamics and fish activity was analyzed under different operating conditions in No.1 ship lock. Between 10:15, April 26 and 7:10, April 27, 2013, the No. 1 ship lock opened and shut 14 times. Fixed-detection was conducted, near the lock head, for 40-45minutes during each cycle; 15 minutes before the lock opened, 10-15 minutes during the water release period and 15 minutes after the lock closed. Results show that fish density during water release was higher than before the lock opened and after the lock closed. Fish density during all phases of the operational cycle tended to decrease from 10:00am to 7:00am the next morning. Fish density peaked at noon (11:00-12:00) before the lock opened, while fish density during water release and after the lock closed peaked from 10:00-11:00. Water releases from the No.1 ship lock had a large influence on the flow velocity and DO concentration in the region near the lock, while no obvious influence was observed for pH and temperature. Correlation analysis showed that fish density was significantly related to the flow velocity and DO, while there was no significant correlation with pH and temperature. In conclusion, release of water from the ship lock changed the water environment near the lock and fish were clearly induced into the downstream entrance of the lock chamber. This study will supply basic data for a study on the feasibility of the ship lock serving as a fish passage and provide new insights on fish behavior.