To solve a problem, you have to understand it. The foundation takes a logical approach to solving issues.
We have found a range of problems that had combined to damage fish stocks and the river environment as a whole. In the 1990’s and 2000’s barriers to fish migration, diffuse and point pollution, excessive soil loss in Herefordshire, acidification and habitat degradation were the primary causes.
It wasn’t simply the number of problems but also the extent to which each and almost every part of the Wye catchment had been affected that had caused the severity of the decline in the 1990’s.
Some of the old problems are still with us and a new suite of direct and compounding issues have arisen that together have caused our rivers to fall into decline again. The foundation is working to understand and resolve them.
More details on the various issues facing the rivers are given below.
They can be split into the direct issues and the compounding issues that are either exacerbating the direct or limiting our ability to solve them. We are currently working across all these issues in the logical way described and you can see what we are doing by clicking on each issue.
Before 2019 severe floods occurred once every 8 years, since 2019 they have been occurring once every 7 months. This is having severe impacts on the rivers’ ecology
Up to 75% of salmon smolts on the Usk fail to reach the tide during dry springs
This is an all too common problem, banks are being eroded by stock and severe floods, we still have too many weirs and dams impacting fish migration and geomorphology and streams are still being straightened
Twenty years ago the streams of the upper Wye and Irfon catchment appeared to be in pristine condition. But taking a closer look would reveal they were lifeless – no fish, invertebrates, plant life or even slime on the stones.
This had been caused by an increase in the frequency and intensity of flushes of acidity flowing into them after rainfall. The result was devastating not just for fish but for the ecology of the whole area.
Read more about acidification, how it came about and what the Foundation and its partners have done to correct it.
In the past we had problems with sheep dip, now a new suite of chemicals is impacting on our rivers
Algal blooms have occurred in both rivers for some years. However, since 2016 these blooms have become much more severe and prolonged, turning the water anything from a light green to dark brown in colour.
The problem is caused by a combination of sunlight, low flows and elevated levels of phosphate in the water.
All fish species are subject to predation by other fish, by avian predators such as herons, dippers and kingfishers and by mammals such as otters.
These predators have existed in the Wye and Usk catchments for millennia and are an important part of the natural environment.
However, the impacts of predation are more significant when the population of a prey species is already depleted. Such impacts may be even more adverse when a new predator species arrives on the scene.
Implications of High Water Temperatures on Salmon and Trout Fisheries:
A Scientific Perspective
Increasing water temperatures are having a serious affect on the ecology of the Wye and Usk and the fishery they support. As global temperatures inexorably rise, unless we change how we are managing our catchments to mitigate rather than exacerbate climate change the effects will become ever more pronounced and serious.
Scientific insights into the consequences of high water temperatures on salmon and trout provide a sobering perspective on the challenges ahead. As we grapple with climate change, adopting science-based management strategies becomes imperative for preserving the ecological integrity of freshwater systems and sustaining the delicate balance of these iconic cold-water fish populations.
Soil loss from land infills gravel, suffocating fish eggs and reducing invertebrate numbers.