Data from: A toolkit for optimizing fish passage barrier mitigation actions

1. The presence of dams, stream–road crossings and other infrastructure often compromises the connectivity of rivers, leading to reduced fish abundance and diversity. The assessment and mitigation of river barriers is critical to the success of restoration efforts aimed at restoring river integrity. 2. In this study, we present a combined modelling approach involving statistical regression methods and mixed integer linear programming to maximize resident fish species richness within a catchment through targeted barrier mitigation. Compared to existing approaches, our proposed method provides enhanced biological realism while avoiding the use of complex and computationally intensive population/ecosystem models. 3. To estimate barrier passability quickly and at low cost, we further outline a rapid barrier assessment methodology. The methodology is used to characterize potential passage barriers for various fish species common to the UK but can be readily adapted to different planning areas and other species of interest. 4. We demonstrate the applicability of our barrier assessment and prioritization approach based on a case study of the River Wey, located in south-east England. We find that significant increases in species richness can be achieved for modest investment in barrier mitigation. In particular, dams and weirs with low passability located on mid- to high-order streams are identified as top priorities for mitigation. 5. Synthesis and applications. Our study shows the benefits of combining a coarse resolution barrier assessment methodology with state-of-the-art optimization modelling to cost-effectively plan fish passage barrier mitigation actions. The modelling approach can help inform on-the-ground river restoration decision-making by providing a recommended course of action that best allocates limited resources in order to restore longitudinal connectivity and maximize ecological gains.

1. 水坝、跨溪道路构筑物及其他基础设施往往会破坏河流连通性，导致鱼类丰度与多样性下降。对河流阻隔物开展评估与修复治理，是恢复河流完整性的修复工作取得成功的关键所在。
2. 本研究提出一种融合统计回归方法与混合整数线性规划（mixed integer linear programming）的联合建模方案，旨在通过针对性的阻隔物修复治理，最大化集水区（catchment）内定居性鱼类的物种丰富度。相较于现有研究方法，本研究提出的方案在避免使用复杂且计算成本高昂的种群/生态系统模型的同时，提升了生物学合理性。
3. 为实现低成本、高效率的阻隔物过鱼能力评估，本研究进一步提出一套快速阻隔物评估方法。该方法可用于表征英国常见多种鱼类的潜在过鱼阻隔特征，同时可轻松适配不同规划区域与其他目标物种。
4. 本研究以英格兰东南部的韦伊河（River Wey）为案例，验证了所提出的阻隔物评估与优先级排序方案的适用性。研究发现，仅需对阻隔物修复治理投入适度资金，即可显著提升鱼类物种丰富度。其中，中高阶溪流上低过鱼能力的水坝与堰坝被确定为修复治理的首要优先级对象。
5. 综合与应用：本研究证实，将低分辨率阻隔物评估方法与前沿优化建模手段相结合，可实现鱼类过鱼阻隔修复治理行动的低成本规划。该建模方案可通过推荐最优资源分配方案，为实地河流修复决策提供依据，从而恢复河流纵向连通性并最大化生态效益。