It has been native to Britain for thousands of years and was heralded as the national fish on the BBC’s Springwatch, but a government report suggests the brown trout risks being wiped out in large parts of England within decades.

The first national temperature projections for English rivers by the Environment Agency forecasts that by 2080 the water will be too warm almost everywhere in England at the height of summer for the Salmo trutta species to feed and grow.

It is further suggested by the chief scientist’s group’s report that the important temperature threshold of 12C for the survival of brown trout eggs during the winter spawning season from November to February will be exceeded by 2080 at more than 70% of the sites where temperatures were modelled.