Degraded Habitat Expand For many fish species, the smaller rivers and streams of a catchment are vital for spawning and juvenile habitat. The state of the tributaries and the quality of the water flowing out of them also has a direct influence on the flora and fauna that inhabit the main river. During our surveys of the upper Wye in the mid 1990s we found the habitat of nearly all the tributaries was in a poor state. We found a similar situation a few years later when we came to the Usk and other parts of the Wye catchment. How and why habitat degradation happens. What the Foundation does to restore habitat in streams and rivers.
Severn Tidal Power Expand The Severn Estuary has the second largest tidal range in the world. The possibility of harnessing that energy for power generation has been mooted from the 1800s. The latest proposals involve the building of a tidal lagoon at Swansea Bay, as a prelude to building several more near Cardiff, Newport and elsewhere. The developers have gone to great lengths to promote the scheme as being both environmentally and ‘people’ friendly. However, the Foundation is concerned over the high cost of electricity production, damage to fish stocks and the significant and permanent changes in the Bay. In Cornwall, there will be negative effects of quarrying the stone required to build the lagoon. If built, there may also be unresolved problems of siltation too. Read more on Severn Tidal Power.
Water Pollution Expand The Wye and Usk have suffered pollution from various sources over the years. The Foundation invests much time and effort in stopping pollutants from entering watercourses. Where they have, we restore the ecology of the rivers and streams that have been affected. Read more about pollution, it's sources and our work to prevent pollution in the Wye & Usk catchments.
Barriers to Fish Migration Expand When it comes to fish migration, most people’s thoughts turn immediately to Atlantic salmon leaping over waterfalls on their way to the headwaters to spawn. However, nearly all river fish migrate to some degree and for various reasons. The ability to do move freely up and down a river system is therefore essential for healthy fish populations. When the Foundation started in 1996, large areas of the Wye and Usk catchments had become blocked to migrating fish. The majority of these barriers were on tributaries. As a result, the biggest negative impact was on salmon and trout who use the smaller streams to spawn. Read more about barriers to migration and the Foundation’s work to restore access.
Exploitation of fish stocks Expand For Atlantic salmon in particular, the exploitation of stocks by humans remains a controversial issue. In the past, it has taken its toll on their overall numbers, occurring throughout the adult stages of their life cycle. Even juvenile salmon haven’t always been spared. A hundred years ago netting smolts as they migrated out to sea was not uncommon. Other fish are also taken, such as brown trout and coarse species but in nowhere near the same numbers or at levels that have threatened their survival. Read more about human exploitation of salmon and what the Foundation has done to encourage their conservation.
Salmon Hatcheries Expand Despite their closure in Wales in 2015, salmon hatcheries have remained a controversial and divisive subject. At a glance, they can appear a viable fishery management option. They involve taking adult salmon out of the river and artificially rearing their progeny in protected surroundings away from predators and other threats such as poor water quality. The young fish are then re-introduced to the river at a later date. This may sound logical enough. Yet in most instances and for a variety of reasons, hatcheries are not the answer to declining salmon populations. In some cases it could even be argued that they have been a hindrance to recovery themselves. The Foundation believes strongly that solving the issues that affect the river (i.e. treating the cause and not the symptom) is the most effective way of delivering improvements to fish populations. Salmon hatcheries are a large and, at times, complex subject. Read more about them, the arguments for and against and their history in the management of the Wye and Usk.
Predation Expand 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. Read more about predation in the Wye and Usk and what the Foundation has done to mitigate the effects on already-depleted fish species.
Acidification Expand 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.