Fish Passage

The Colne Valley Park has over 200km of river and canals with over 60 lakes which host a wide variety of 16 native fish species including: Barbel, Bleak, Bream, Carp, Chub, Dace, European Eel, Gudgeon, Perch, Pike, Roach, Ruffe, Rudd, Sliver Bream, and Tench. A large proportion of these species are migratory, requiring free movement along watercourses to reach different habitats needed at crucial points in their life cycle, e.g. spawning sites and juvenile recruitment sheltering. Migration distance varies from species to species for example Dace (Leuciscus leuciscus) have been recorded travelling up to 16km; but the European eels, (Anguilla anguilla), a ‘Critically Endangered’ species identified on the IUCN Red List of Threatened Species, have the largest migration distance travelling from their spawning grounds in the Sargasso sea to European river systems, travelling over 5000km. This highlights the importance of free travel for coarse fish species’ long term survival.

Humans have altered and modified river systems for millennia, often constructing man made structures such as weirs and sluices which prevent the free passage of migratory fish upstream. To mitigate the negative effects on fish migration the Landscape Partnership Scheme are leading a ’Fish Passage’ project to improve the natural flow within the river corridor for fish by altering historic man-made structures along the river of the Colne Valley enabling free movement.

Tom White, the Project Manager for the Colne Valley Catchment Scheme, working alongside project partners in the Colne Valley Park, installed fish and eel passages at Kingfisher weir along the River Colnebrook and Hithermoor weir along the River Colne. The successful modification of these two weirs has improved the natural flow within the river corridor for fish in two local rivers. For more information take a look at the article released on the Colne Valley website here.