Data from: A toolkit for optimising 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 paper, we present a combined modelling approach involving statistical regression methods and mixed integer linear programming to maximise 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 characterise 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 prioritisation 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 optimisation 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 maximise ecological gains.1. 水坝、跨河道路交叉设施及其他水利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减缓改造，对于旨在恢复河流完整性的修复工程而言至关重要。 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，通过针对性的阻隔物改造，实现流域内土著鱼类物种丰富度的最大化。相较于现有研究方法，本方案在提升生物学真实性的同时，避免了使用复杂且计算成本高昂的种群/生态系统模型。 3. 为快速且低成本地评估阻隔物通行能力（barrier passability），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通行阻隔特征，同时可轻松适配至不同规划区域与其他目标物种。 4. 我们以英格兰东南部的韦伊河（River Wey）为案例研究对象，验证了本研究提出的阻隔物评估与优先级排序方法的适用性。研究发现，仅需适度投入阻隔物改造资金，即可实现物种丰富度的显著提升。其中，分布于中高等级溪流、通行能力低下的水坝与堰坝，被确定为优先开展改造的核心对象。 5. 综合与应用。本研究表明，将粗分辨率阻隔物评估方法与前沿优化建模相结合，可实现鱼类通行阻隔物改造行动的低成本规划。该建模方案可通过推荐最优行动方案，实现有限资源的最优配置，从而恢复河流纵向连通性并最大化生态效益，以此为实地河流修复决策提供科学参考依据。