Upstream spawning migration of river lamprey (Lampetra fluviatilis) in the River Trent, 2020-2021

This study investigated the upstream spawning migration of anadromous river lamprey (Lampetra fluviatilis) in the River Trent, a heavily fragmented tributary of the Humber Estuary- the location of one of the largest river lamprey populations in the UK. River lamprey released upstream (n = 16) and downstream (n = 15) of Cromwell Weir were tracked from the upper estuary (Keadby) to upstream of the fourth weir encountered (Gunthorpe Weir). Receivers were also located in the Yorkshire Ouse catchment, which joins with the Trent at Trent Falls (to create the Humber Estuary). Overall, this study quantified river lamprey migration, spawning habitat distribution and historic river levels to develop a novel empirical index to understand the impact of man-made barriers and prioritise their remediation.本研究针对英国最大河七鳃鳗种群分布地之一的亨伯河口（Humber Estuary）的重度碎片化支流特伦特河（River Trent），开展了溯河洄游性河七鳃鳗（Lampetra fluviatilis）的上游产卵洄游行为调查。研究人员对克伦威尔堰（Cromwell Weir）上游（n=16）与下游（n=15）放流的河七鳃鳗进行了追踪，追踪范围从河口上游的基德比（Keadby）延伸至途经的第四座堰坝——冈索普堰（Gunthorpe Weir）的上游区域。此外，研究团队还在约克郡乌斯河流域（Yorkshire Ouse catchment）布设了水声接收装置，该流域于特伦特福尔斯（Trent Falls）与特伦特河交汇，共同形成亨伯河口。综上，本研究通过量化河七鳃鳗的洄游行为、产卵栖息地分布及历史河流水位数据，构建了全新的经验性指标，旨在阐明人工阻隔物的生态影响并优先推进其修复工作。