三峡水库生态调度期间监利江段产漂流性卵鱼类自然繁殖变化特征研究OA

To investigate the promoting effects of the ecological operation of the Three Gorges Reservoir on the natural reproduction of drifting-egg fish in the Jianli section,this study conducted surveys on the early-stage fish resources in the middle reaches of the Yangtze River at the Jianli section from 2014 to 2022.During the sur-vey period,a total of 34 fish egg species were collected in the Jianli section,among which 25 species belonged to drifting-egg fish,mainly including Hemicuter bleekeri,Squalidus argentatus,Saurogobio dabryi,Parabramis pekinensis,Ctenopharyngodon idellus,Leptobotia taeniaps.The average annual runoff of eggs was 2.899 billion,ranging from 2.098 to 3.908 billion,and the total annual runoff of fish fry was 70.669 billion,ranging from 26.189 to 153.912 billion.Based on the ratio of the average daily spawning scale during the ecological dispatch period to that during the non-dispatch period,it could be known that since 2014,the ecological dispatch had promoted the reproduction of drift-spawning fish in the Jianli section,with better effects in 2014,2015,2016,2018,2019,2021 and 2022.Based on the correlation analysis between spawning scale and hydrological indicators,the spawning quantity of drifting-egg fish in the Jianli section showed a significant positive correlation with peak dis-charge(R=0.421,P<0.01),discharge increase(R=0.568,P<0.05),and rising-water duration(R=0.688,P<0.01).Moreover,conditions more conducive to the reproduction of drifting-egg fish in the Jianli section oc-cur when the rising-water duration exceeded 3 days,the discharge increase reached above 1900 m3/s,and the peak discharge exceeded 15100 m3/s.The research findings provide technical references for the assessment of ecological scheduling effects and for the continuous optimisation of the Three Gorges ecological scheduling plan.