The Upper Wye Tributaries Survey 1996

The results of the NRA survey of some salmon spawning tributaries in 1995 (carried out at our instigation) showed so many timber blockages that we felt it essential to organise our own comprehensive survey of the entire upper catchment. We included every stream and, as well as noting all timber blockages, we discovered the whereabouts of all structures such as weirs, culverts and natural falls. Additionally, we measured the pH during steady flows and when the system started to rise after rain. Checks on invertebrate life provided information on the potential productivity of each stream. Richard White, our habitat officer, started his tour with the upper Ithon, and it was soon apparent how little was known about the salmon population of many of these streams. Even if they had been productive in the past, a great many had dams of trees across them making access impossible or very difficult for spawning salmon. After six weeks Richard had walked the full length of every tributary upstream of Glasbury bridge.

Impassable

In general terms, the streams that enter the main river above Newbridge offer a different set of problems in that a considerable number of them have impassable falls or road culverts blocking access by ascending fish. Nearer the source, the pH of one tributary, the Tarenig, showed such a low reading that the diagnosis of acid rain exacerbated by conifer plantations, needed only the invertebrate study for confirmation.  Below Builth it was heartening to learn that many of the streams had all the hallmarks of ideal spawning streams but for obstruction by timber blockages that are readily removable, and one or two streams were actually in good order. The Irfon catchment contained a mixture of all the above. It was pleasing to record that the ghillies clearing work last year had kept some streams such as Chwefru open. 

The results of Richard's survey have been summarised in tabular form. Each stream's quality is assessed and an estimate is made of its value in terms of additional fish rearing potential if opened up. An idea of manpower needed to rectify the situation is also recorded. The extent of the problem may be gauged from the following: Structural blockages 5 pages Removal debris blocks 11 pages BLOCKAGES In conclusion, the accumulation of timber blockages on spawning streams, which has been allowed to take place over the last ten years, has gradually shut off an increasing area of the upper Wye catchment to spawning salmon. Using the NRAs own calculations for stocking, these closed off areas could have produced up to 1,119,300 additional salmon fry! The good news is that we will have removed all these blockages by this spawning season. Please contact Richard White if you would like to help in this task.

Encouraging Start to the Season

After a very quiet start in March and early April, the season picked up dramatically during May.This year water conditions enabled fish to run the length of the river and there were many reports of large fish seen and caught. This is particularly encouraging after the poor season we had in 1995.The fact that large spring salmon have re-appeared in the Wye provides us with great encouragement for the spring salmon hatchery programme. It is clear evidence that all is not lost with these large fish and it is worth devoting considerable resources to increasing their number by stocking out young fish derived from these large salmon in the headwaters and carrying out habitat improvement work in the areas where they are believed to spawn.