水动力驱动的典型鱼类动态响应与闸坝运行调控机制

Coupling of hydrodynamic environment and ecological processes with fish as indicator species is not only the key to quantify and predict the impacts of changing hydrological regime and dynamic spatial pattern on ecological process due to the regulation of water projects, but also the foundation of developing water projects ecological scheduling optimization model.This study, taking typical water project--Bengbu dam in Huaihe basin as an example, is to research dynamic response of fishes with the action of hydrodynamic and the pattern of dam management basing on multi-disciplinary knowledge including hydrology, hydraulics and biology. Meanwhile the lab flume experiment, fish farms experiment and outdoor investigation are conducted in this study combining with numerical simulation. The objectives of this study are to: (1) investigate typical fishes growth habit under different hydrodynamic conditions; (2) find out the appropriate flow velocity and water temperature through experimental study; (3) research dynamic response of typical fishes to hydrodynamic and water temperature structure changes; (4) research ecological pattern of dam management basing on a 3D numerical fish habitat model. This study will provide a technological support for revealing the effect of action of hydrodynamic on fishes growth, constructing dam and optimizing dam layout reasonably, and formulating dam management pattern considering rivers ecological flow.

水动力条件和以鱼类为指示物种的生态过程的耦合研究是量化和预测闸坝导致 河流的水文情势和水动力空间格局改变对生态过程影响的关键，也是闸坝工程建设布局和运行调控方案制定的基础。本项目以淮河典型闸坝工程--蚌埠闸为例，通过水文学、水力学、生物学等多学科的交叉融合，利用室内水槽实验、养殖基地中试实验和野外河流调查，结合数学模拟方法，开展了水动力驱动下的典型鱼类动态响应与闸坝运行调控机制研究。具体为：（1）不同水动力条件下典型鱼类生长习性调查研究；（2）典型鱼类生长的适宜流速和水温试验研究；（3）典型鱼类对水动力和水温结构变化的响应过程；（4）基于三维鱼类栖息地耦合模型的闸坝生态运行调控模式研究。其研究成果能够为揭示水动力驱动对典型鱼类生长行为的影响，科学合理的建设和优化布局闸坝工程，制定考虑河流生态流量的闸坝运行调控模式提供理论支持。

本项目以淮河流域典型闸坝工程——蚌埠闸为例，选择淮河流域河流典型鱼类—鲫鱼为研究对象，利用室内外实验和数学模型，调查了研究不同水动力条件下典型鱼类生长习性，明确了典型鱼类生长的适宜流速和水温，探讨鱼类生长对水动力和水温条件变化的行为响应特征与机理。结果表明，鲫鱼的体重及增长量随流速增加而减少,而超氧化物歧化酶（SOD）和淀粉酶（AMY）的活性基本随着水流速度增大而增强；高流速区域鲫鱼生物酶的变化尤其显著，而低流速区域变化较小。水温对SOD活性的影响没有显著规律，溶解氧（ROS）活性总体随温度的降低而下降；偏低温环境（15-22℃）下谷丙转氨酶（GPT)活性明显高于高温情况；AMY活性随温度升高总体呈现先增后减的趋势。温度骤变会短时间内促进鲫鱼GPT、SOD、ROS活性的增强；而温度骤降促进鲫鱼AMY活性的增强，温度骤升会使鲫鱼AMY活性的降低。 结果表明高流速对鲫鱼产生胁迫作用，温度骤变会使鲫鱼生物酶产生应激变化。本研究结果可为揭示水动力驱动对典型鱼类生长行为的影响，科学合理的建设和优化布局闸坝工程，制定考虑河流生态流量的闸坝运行调控模式提供理论和基础数据支持。