Department of Civil and Environmental Engineering, University of New Hampshire, Durham, NH, United States.
Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, ME, United States.
Sci Total Environ. 2019 Jun 15;669:833-843. doi: 10.1016/j.scitotenv.2019.03.042. Epub 2019 Mar 6.
Management activities to restore endangered fish species, such as dam removals, fishway installations, and periodic turbine shutdowns, usually decrease hydropower generation capacities at dams. Quantitative analysis of the tradeoffs between energy production and fish population recovery related to dam decision-making is still lacking. In this study, an integrated hydropower generation and age-structured fish population model was developed using a system dynamics modeling method to assess basin-scale energy-fish tradeoffs under eight dam management scenarios. This model ran across 150 years on a daily time step, applied to five hydroelectric dams located in the main stem of the Penobscot River, Maine. We used alewife (Alosa pseudoharengus) to be representative of the local diadromous fish populations to link projected hydropower production with theoretical influences on migratory fish populations on the model river system. Our results show that while the five dams can produce around 427 GWh/year of energy, without fishway installations they would contribute to a 90% reduction in the alewife spawner abundance. The effectiveness of fishway installations is largely influenced by the size of reopened habitat areas and the actual passage rate of the fishways. Homing to natal habitat has an insignificant effect on the growth of the simulated spawner abundance. Operating turbine shutdowns during alewives' peak downstream migration periods, in addition to other dam management strategies, can effectively increase the spawner abundance by 480-550% while also preserving 65% of the hydropower generation capacity. These data demonstrate that in a river system where active hydropower dams operate, a combination of dam management strategies at the basin scale can best balance the tradeoff between energy production and the potential for migratory fish population recovery.
管理活动旨在恢复濒危鱼类物种，如拆除水坝、安装鱼类通道和定期关闭涡轮机，这些活动通常会降低水坝的水力发电能力。在大坝决策中，仍然缺乏对能源生产和鱼类种群恢复之间权衡关系的定量分析。在这项研究中，我们使用系统动力学建模方法开发了一个综合的水力发电和年龄结构鱼类种群模型，以评估在八种水坝管理情景下，流域尺度的能源-鱼类权衡关系。该模型在每天的时间步长上运行 150 年，应用于缅因州彭诺斯科特河干流上的五座水力发电大坝。我们使用鲱鱼（Alosa pseudoharengus）作为当地洄游鱼类种群的代表，将预测的水力发电与模型河流系统中对洄游鱼类种群的理论影响联系起来。我们的研究结果表明，虽然这五座大坝每年可产生约 427 吉瓦时的能源，但如果不安装鱼类通道，它们将导致鲱鱼产卵量减少 90%。鱼类通道的安装效果在很大程度上受到重新开放栖息地面积的大小和鱼类通道实际通过的影响。洄游到出生地的影响对模拟产卵量的增长影响不大。在鲱鱼下游洄游高峰期运行涡轮机关闭，以及其他水坝管理策略，可以有效地增加产卵量 480-550%，同时保留 65%的水力发电能力。这些数据表明，在一个有活跃水力发电大坝的河流系统中，流域尺度的水坝管理策略组合可以在能源生产和洄游鱼类种群恢复的潜力之间实现最佳平衡。
