There have not been many reported cases of fishy deaths at commercial fisheries this year, but the sudden mass death of quality roach at Drayton Reservoir has fisheries scientists scratching their heads.

The carp at the British Waterways controlled water (now known as the Canal and River Trust) appear to have been completely unaffected and despite multiple tests on some of the dead roach, Environment Agency experts appear to be no nearer an explanation. Low oxygen levels, parasites and poisonous algae have been dismissed as possible causes. “The EA found no signs of disease or parasites and in five years of looking after the reservoir I have never seen anything like it,” said bailiff Mark Ryder.