In 40 years’ time, some of the most popular fishing rivers in England and Wales could be running virtually dry during the summer, according to an Environment Agency study.
The effects of climate change, coupled with an increasing demand for fresh water from the public, mean average flows in rivers such as the Severn, Mersey and upper Thames are predicted to be between 50 per cent and 80 per cent down on current summer levels, the EA has warned in its new Water Resources Strategy report.
The west of England and large swathes of Wales will be hardest hit, although angler favourites such as the Dorset Stour, Hants Avon and Kennet will also suffer from greatly depleted flows, typically 30 per cent to 50 per cent lower.
A range of fish species could be hit as a result, especially those which rely on strong flows for spawning, including most salmonids as well as a range of popular coarse species like barbel, chub and dace.
The report’s main author, Andy Turner, EA water resources policy manager, explained: “We’ve known for some time that the implications of climate change were serious for river flows, but this is the first time we have been able to get a feeling for the location, timing and impact of the effects.
Numerous habitats and species will be affected, with some disappearing altogether.
“The worst affected areas will be those that are not supported by groundwater ¬ typically river headwaters. It may be that some vulnerable species will need to be moved. Salmon, for example, could be relocated by moving spawn to rivers with greater flows.”
Mike Dunbar, a hydroecologist at the Centre for Ecology & Hydrology, said that the problems for fish will be compounded by the effects that the reduced flows will have on aquatic plants. He said: “The impact will be right across the food chain, with the balance of plant species and invertebrates being considerably altered. Less flow means vital aquatic plants, such as ranunculus or water crowfoot, will be less widespread. This will have a knock-on effect on the macro invertebrates, which are a vital part of the diet of many species of fish.”