Environment Agency add new gravel spots
Another step has been taken to secure a sustainable breeding population of barbel in Norfolk’s River Wensum with the creation of new gravel areas.
The site near Lyng, managed by Norfolk Anglers Conservation Association (NACA), has been the focus of many years of habitat restoration work led by the Association. In the latest phase of work the Environment Agency has created two new gravel patches of fifteen cubic metres each, close to existing spawning areas.
Some trimming of trees on the sides of the banks was needed to allow access for the machinery and this will be beneficial to the site by allowing more light to penetrate to the river channel, potentially encouraging the growth of plants such as water crowfoot, which has been identified as a possible key plant in barbel stock growth.
Fresh gravel was also added to another riffle (initially created by NACA in the early stages of the Sayers Meadow Habitat Restoration Project) where barbel spawning activity was reported in 2007, and a fry refuge was de-silted whilst machinery was available.
The Lyng fishery is generally recognised as being near the upper limit of barbel spawning on the river. Consequently, work of this type on the spawning habitat could benefit the entire river system below, as any movement of juveniles will be in a downstream direction, upstream movement being blocked by the water control structures at Lyng Mill.
This enlargement of natural gravels, the design and placement of which have been carefully selected to optimize their value as spawning sites, is effectively a trial operation, carried out as part of an ongoing programme of restoration measures that includes the formation of full-width gravel riffles, and regular gravel-jetting to remove silt.
Again, this forms part of a much more wide-reaching project at Lyng, running for nearly twenty years, which has included re-profiling the river bed, planting of riparian vegetation, excavating deeper pools, creating fry-refuges and re-stocking fish where allowable.
NACA welcomes involvement and help from the Environment Agency in facilitating this gravel augmentation pilot scheme, and with future works planned on the river which contribute to the improvements required by the River Wensum Restoration Strategy. NACA look forward to working together in partnership to protect and improve the river as a valuable resource in this region.
NACA vice-chairman Chris Turnbull said: ‘Barbel are of huge importance to the Wensum as a fishery. Without them large reaches of the river have little value as a social/economic angling resource. While barbel are successfully recruiting in some stretches of the river, stocks are dwindling elsewhere. Hopefully this work will start to address this trend by improving spawning sites and boosting fry recruitment.’
Rob Dryden, Technical Specialist with the Agency’s Fisheries, Recreation and Biodiversity Team, said: ‘We are pleased to be working with NACA and the local landowner to implement habitat enhancements that benefit the fishery at Lyng. Over the coming years we will be seeking further opportunities to develop partnership projects aimed at restoring the ecological functioning of the river.’