鱼类产卵行为与生态水文指标响应关系研究——以长江四大家鱼为例

Relationship between Fish Spawning Behavior and Eco-hydrological Indicators:A Case Study of the Four Major Chinese Carps in the Yangtze River

四大家鱼作为我国重要淡水经济鱼类,近年来产卵规模大幅衰减,水文条件作为影响家鱼自然繁殖的重要因素,确定四大家鱼产卵行为与生态水文指标的关系对保护四大家鱼早期资源具有重要意义。以长江中游宜昌段为研究区域,采用ROC曲线、分类回归树、Logistic回归等方法将生态水文指标对家鱼产卵刺激划分为“无效、低效、高效”多分类问题,分析家鱼产卵行为与生态水文指标间的响应关系,并对比研究不同方法间的性能与优缺点。结果显示,ROC曲线判别准确率、预测准确率、模型鲁棒性均最优,是判定生态水文指标对四大家鱼产卵规模影响的最优方法;当流量日增量大于1370 m^(3)/s且两次洪峰间隔时间大于7.5 d时可以引起四大家鱼高效产卵响应。辨识出高效刺激家鱼产卵的生态水文指标及其阈值,对生态调度的优化改进具有重要的现实意义。

As important economic freshwater fish in China,the spawning scale of the four major Chi⁃nese carps has declined significantly in recent years.Hydrological conditions play an important role in the natural reproduction of the four major Chinese carps.Thus,to protect early stage resources of these four species,it is important to determine the relationship between spawning behavior and eco-hydrolog⁃ical indicators.In this study,the Yichang section of the middle Yangtze River was selected for re⁃search,and we analyzed the relationship between the spawning behavior of the four major Chinese carps and eco-hydrological indicators using a receiver operating characteristic(ROC)curve,classifica⁃tion regression tree and logistic regression analysis.The performance,advantages and disadvantages of the three data mining methods were then compared.The study was based on monitoring data for hydrol⁃ogy and reproduction in the investigated section during the period 2013-2023(except 2016,2021).Stimulation of spawning behavior by ecohydrological indicators was analyzed for each of the four spe⁃cies and divided into three levels(no response,low response,and high response).The discrimination ac⁃curacy rates for each method were as follows:ROC curve(71.74%),logistic regression analysis(71.74%)and classification regression tree(60.87%).The prediction accuracy rates of the three meth⁃ods were,respectively 75%,75%and 55%,and the ROC curve was the most robust.Therefore,we rec⁃ommend the ROC curve for estimating the impact of eco-hydrological indicators on the spawning scale of the four major Chinese carps.The best eco-hydrological conditions for effective spawning of the four major Chinese carps was when the daily increment of flow was greater than 1370 m^(3)/s and the in⁃terval time between two flood peaks was more than 7.5 days.In conclusion,our research identified the eco-hydrological indicators and thresholds that effectively stimulate spawning of the four major Chi⁃nese carps.This has important practical significance for optimizing and improving the ecological opera⁃tion of Three Gorges Reservoir.