The impact of small impoundments and connectivity loss on fishdistribution and abundance in river ecosystems: leveraging cutting edge geospatial model

河流是世界上最受威胁的生态系统之一。淡水渔业面临多种压力因素的威胁，包括气候变化、污染物和水坝的存在，这些因素抑制了鱼类的运动和迁徙。从全球范围来看，世界上只有37%的河流没有水坝，但在英国，只有1%的水道没有障碍物，这些障碍物主要是英国的工业遗产。尽管研究已经证明了大型水坝与鱼类数量下降之间的明确联系，但显然缺乏对英国河流典型的较小（但更频繁）历史屏障如何影响鱼类数量的了解。在越来越需要平衡淡水生态系统保护与传统微型水力发电设施和类似结构对可再生能源的需求的背景下，因此迫切需要研究如何了解累积的小历史障碍影响鱼类种群动态。本研究将使用eDNA（通过水样收集的鱼身上的痕量DNA）来量化德比郡德温特（一个具有丰富历史蓄水历史的集水区）内鱼类群落的丰度和分布。通过将种群水平数据与河流连通性模型（与历史屏障和主要鱼类栖息地的存在有关）相结合，该项目将对小型、频繁蓄水对河流栖息地连通性和鱼类种群动态的影响产生新的基本认识，从而为管理受工业发展遗产影响的河流提供重要信息。

Rivers are among the world's most threatened ecosystems. Freshwater fisheriesare at risk from multiple stressors including climate change, pollutants and the presence of dams which inhibit fish movement and migration. Globally, only 37% of the world's rivers remain free of dams, butin the UK only 1% of watercourses unimpeded by barriersduelargely tothe UK's industrial heritage.Althoughresearch has demonstrated clear links between large dams and declines in fish populations, there is aclearlack of knowledge on how smaller (but more frequent)historical barriers typical of UK rivers influence fish populations. In thecontextofincreasing need to balance conservation of freshwater ecosystems against the demandforrenewable energy from legacy micro-hydroelectric facilitiesand similar structures, research isthereforeurgently needed to understand how cumulative small historicalbarriers influence fish population dynamics.This study will use eDNA (trace DNA shed from fish, collected via water samples) to quantify the abundance and distribution of fish communities within the Derbyshire Derwent, a catchment with a rich history of historical impoundment. By coupling population-level datawith river connectivity models relating to the presence of historical barriers and key fish habitats, thisprojectwill generate new fundamental understanding of the impacts of small, frequent impoundments on river habitat connectivity and fish population dynamicsand thus provide important information for managing rivers affected by the legacy of industrial development.