长江上游特有鱼类受总溶解气体过饱和间歇性胁迫影响的规律及减缓措施研究

With more and more high dams being operated at the upper Yangtze River, effects of total dissolved gas (TDG) supersaturation caused by flood discharge on endemic fish were getting more serious. However, rare research achievements on this issue can be found. Problems in mitigating the negtive effects of TDG supersaturation and constituting the ecological regulation of reservoir operation need to be studied. Endemic fish at the upper Yangtze River, such as Chinese sucker, rock carp and prenant's schizothoracin are chosen as the study object in this project. Mechanism and rules of the effects of intermittent exposure to TDG supersaturation on fish will be revealed through indoor controlled experiments and the field experiments during flood discharging by using the basic theory and experimental methods of Biology and Toxicology. Moreover, experiments about abilities of detecting TDG supersaturation and using vertical compensation depth of different fish and different life stages of a fish will be carried out. Based on the experimental results, ecological schemes of reservoir operation on mitigating the effects of TDG supersaturation on fish can be explored. Results of this project can help making protective measures on fish downstream of high dams, providing basic data for evaluating effects of TDG supersaturation on fish at the upper Yangtze River, and establishing the water quality standards of TDG saturation in China.

伴随着长江上游干支流高坝的逐渐建成运行，泄洪引起的下游水体总溶解气体（total dissolved gas,简称TDG）过饱和对鱼类的影响问题日益凸显。关于过饱和TDG对长江上游特有鱼类影响的研究成果较为缺乏，相关减缓措施与水库生态调度方案亟待深入研究。本项目拟在前人研究成果和申请人已取得的研究成果的基础上，以长江上游特有鱼类胭脂鱼、岩原鲤和齐口裂腹鱼为研究对象，运用生物学与毒理学的基础理论和实验方法，通过室内受控实验和实际工程泄水期间的现场实验，揭示鱼类受过饱和TDG间歇性暴露影响的机制和规律；开展不同鱼类以及同一鱼种的不同生长阶段对过饱和TDG的探知能力和利用垂向补偿水深能力的系统实验研究；在此基础上探索减缓过饱和TDG对鱼类影响的水库生态调度方案。成果可为定量评价过饱和TDG对长江上游特有鱼类的影响、制定高坝工程的鱼类保护措施以及确定水体TDG饱和度质量标准提供基础数据和科学依据。

伴随着长江上游干支流高坝的逐渐建成运行，泄洪引起的下游水体总溶解气体过饱和（total dissolved gas supersaturation,简称TDGS）对鱼类的影响问题日益凸显。为探究长江上游特有鱼类受TDGS间歇性胁迫影响的规律，以及减缓长江上游过饱和气体对鱼类影响的措施，本项目以室内与现场实验为手段，结合数值模拟，开展了以下研究工作：.（1）研究了齐口裂腹鱼等长江上游特有鱼类间歇暴露于TDGS水体中的耐受性；（2）以向家坝、大岗山为现场实验点，研究了实际高坝工程泄水期间过饱和TDG对齐口裂腹鱼等长江上游特有鱼类、以及草鱼等长江上游经济鱼类的影响；（3）从TDGS变化规律、鱼类气泡病现象、鱼类对TDGS等三方面阐明了现场间歇性暴露实验与实验室受控实验的差异性；（4）研究了齐口裂腹鱼等长江上游特有鱼类对过饱和TDG的探知能力及利用补偿水深能力；（5）提出了减缓过饱和TDG对鱼类影响的水库生态调度原则；（6）提出了基于长江上游特有鱼类的120%TDG饱和度限值。.此外，在已有的基础上，开展了过饱和TDG胁迫下鱼类游泳能力的研究、“TDGS-泥沙”耦合作用下、以及“TDGS-水温”耦合作用下齐口裂腹鱼耐受性研究、鱼类对过饱和TDG的躲避空间研究、TDGS对长薄鳅的影响研究、以及高坝TDGS对鱼类影响的预测等相关方面的研究内容。.项目成果丰富，可为定量评价过饱和TDG对长江上游特有鱼类的影响、制定高坝工程的鱼类保护措施以及确定水体TDG饱和度质量标准提供基础数据和科学依据。