Upstream behavior of <i>Schizothorax wangchiachii</i> after crossing dams at Songxin Hydropower Station in Heishui River,a tributary of the Jinsha River

Abstract

鱼类过坝后的上溯行为对鱼类寻找适宜的产卵、索饵等功能性栖息地至关重要。现阶段我国大多数研究聚焦于鱼类上溯通过鱼道的游泳行为量化,而过坝后的上溯行为分析鲜有报道。本研究在金沙江下游支流黑水河松新坝址处利用PIT(passive integrated transponder)遥测技术对松新电站过鱼对象短须裂腹鱼(Schizothorax wangchiachii)过坝后的上溯行为开展监测,考虑监测过程中水文情势变化对过坝后上溯行为的影响,采用生存分析方法,构建了耦合多因素(流量、水温、河道涨落水率、昼夜节律、肥满度等)的Cox风险比例回归模型,利用AIC模型准则筛选出最优模型参数,识别了影响鱼类过坝后上溯成功率的关键因素。结果表明:(1)短须裂腹鱼在松新鱼道的上溯效果显著优于河道;(2)水温及河道涨落率是影响短须裂腹鱼过坝后上溯效果的关键因素;(3)水温与短须裂腹鱼过坝后河道上溯成功率呈负相关,当水温超过短须裂腹鱼最适温度后,河道上溯成功率随着温度的上升呈递减趋势;河道涨落水率与短须裂腹鱼过坝后河道上溯成功率呈正相关,其中涨水情势下短须裂腹鱼河道成功上溯的概率高于落水,河道上溯成功率随着涨水率增大呈递增趋势;(4)尽管昼夜节律对短须裂腹鱼过坝后河道上溯成功率无显著影响,但从数据结果发现有61%的短须裂腹鱼选择在夜间上溯。本研究旨在为恢复鱼类栖息地和优化小水电生态调度提供科学依据及参考价值。;The upstream behavior of fish after crossing the dam is critical for fish to find suitable functional habitats for spawning, baiting, etc. At present, most researches in China focus on quantifying the swimming behavior of fish upstream through the fishway, while the analysis of upstream behavior after crossing dams has rarely been reported. In this study, passive integrated transponder (PIT) telemetry was used at the Songxin Dam in the Heishui River, a tributary of the lower Jinsha River, to monitor the upstream behavior of Schizothorax wangchiachii, the target fish of Songxin Power Station, after crossing the dam. In view of the influence of changes in hydrological conditions on post-damming upstream behavior during monitoring, a Cox proportional regression model coupled with multiple factors (flow, water temperature, river rise and fall rate, diurnal rhythm relative fatness, etc.) was established by using survival analysis method. Meanwhile, the optimal model parameters were selected by utilizing the AIC model guideline to identify the key factors affecting the efficiency of fish's post-damming upstream movement. The results indicated that(1)The upstream effect of Schizothorax wangchiachii in the Songxin fishway passage rate is significantly better than that in the river channel; (2)Water temperature and rise and fall rate of river discharge are the key factors affecting the passage efficiency of Schizothorax wangchiachii after crossing the dam; (3)Water temperature was negatively correlated with the success rate of river upstream after Schizothorax wangchiachii crossed the dam, and when the water temperature exceeded the optimum temperature for Schizothorax wangchiachii, the success rate of river upstream was decreasing with temperature; The upstream success rate of Schizothorax wangchiachii after crossing the dam was positively correlated with the rate of river rise and fall rate, where the river successful upstream rate of Schizothorax wangchiachii in the situation of rising water is higher than that in falling water, and the river upstream success rate was increasing with water rise rate; (4)Although there was no significant effect of diurnal rhythm on the success of river upstream after crossing the dam for Schizothorax wangchiachii, the results showed that 61% of Schizothorax wangchiachii chose to upstream at night. This research provides scientific basis and reference for restoring fish habitat and optimizing ecological planning of small hydropower plants.