Aquaculture for all

Climate Change Invaders threat to River Usk

WALES - Climate change and the spread of invasive species are the two major issues affecting the quality of the River Usk. These were the principal themes to come out of a recent conference in Abergavenny hosted by the Countryside Council for Wales (CCW).

Problems have been identified, such as the impacts of barriers on migrating fish; the spread of invasive species, which are in danger of smothering other wildlife; and silt runoff from nearby land, which affects the quality of the water.

“Climate change was highlighted as a major concern. In the future, IT may mean we have too little water for both wildlife and people, especially in summer, ” said Tristan Hatton-Ellis, CCW’s Senior Freshwater Ecologist.

The Beautiful Usk Valley is threatened by invasive speciaies

Although the Usk itself is relatively rural, development pressure in Newport and along the M4 motorway corridor is increasing water demands and more frequent storms are creating environmental pressures. There will be huge changes to land use that will present challenges for river management in the very near future.


Invasive species were of particular concern. Currently there were 11 invasive species affecting the river Usk - the worst invaders being signal crayfish and giant hogweed.

“The signal crayfish is an escape from commercial aquaculture. It’s big and aggressive and eats smaller crayfish and has brought crayfish plague, which kills the native species,” he said and compared it with the devastation inflicted on the UK's native red squirrel by the North American grey.

The systematic annual spraying of hogweed in a co-ordinated assault involving local landowners, the Environment Agency, Keep Wales Tidy and local authorities was beginning to have some effect.

Other issues affecting the current and future quality of the Usk Valley, a Special Area of Conservation (SAC)in Mid Wales are:
  • River flow – ensuring the river contains enough water, especially in summer, is crucial to protecting wildlife Development pressure – for example, from Newport’s Urban Regeneration scheme
  • Ecological connectivity - the need to link up habitats so that species can move around the river in response to climate change.
Mr Hatton-Ellis concluded that a consensus was established at the conference and even under current pressures, the Usk remained in a relatively good condition, especially in terms of water quality and river habitats.

"This reflects the river’s international importance for conservation. It also highlights the need to invest in resources and work together to secure a healthy future for the river," he added.

Comments and issues raised at the conference will be used to support recommendations to the Severn River Basin District Liaison Panel. This group is responsible for the strategic management of the Usk under the Water Framework Directive.

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