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、跨河道路交叉口（stream–road crossings）及其他人工基础设施往往会破坏河流连通性（river connectivity），导致鱼类丰度与多样性下降。对河流障碍（river barriers）开展评估与整治，是恢复河流完整性的修复工程取得成功的关键所在。2. 本研究提出一种结合统计回归方法（statistical regression methods）与混合整数线性规划（mixed integer linear programming）的联合建模方案，旨在通过针对性的障碍整治，最大化集水区内的土著鱼类物种丰富度。相较于现有方法，本研究提出的方案在规避复杂且计算负荷高昂的种群/生态系统模型的同时，提升了生物学真实性。3. 为实现低成本快速评估障碍物通行性（barrier passability），本研究进一步提出一套快速障碍评估方法。该方法可用于表征英国境内常见多种鱼类的潜在通行障碍，且可轻松适配至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，验证了所提障碍评估与优先级排序方法的适用性。研究发现，仅需投入适度的障碍整治资金，即可实现物种丰富度的显著提升。其中，分布于中高阶溪流且通行性较低的水坝与堰坝（weirs）被确定为优先整治的核心对象。5. 综合与应用：本研究证实，将粗分辨率（coarse resolution）障碍评估方法与前沿优化建模（state-of-the-art optimization modelling）相结合，可实现鱼类通行障碍整治行动的低成本高效规划。该建模方案可通过推荐最优行动方案，合理分配有限资源以恢复河流纵向连通性（longitudinal connectivity）并最大化生态效益，从而为实地河流修复决策提供科学依据。