Fish numbers have fallen by 92% in a once prolific Fenland Drain, which is under threat from over-abstraction and siltation.
Surveys carried out by the Environment Agency earlier this year show stocks of roach and bream have almost completely collapsed in parts of the Old Bedford River. Few adult fish remain in isolated pockets around Welney and Welches Dam.
Despite this, EA officials have allowed turbid water from the tidal Ouse to flow into the drain all summer, to restore levels after abstraction by drought-hit farmers.
Large amounts of blanket weed have also been pushed through the sluice, prompting fears fish could be wiped out completely in the lower reaches.
The Bedford was dredged in 2003, after a catastrophic fish kill claimed thousands of pike, tench and silver fish. Experts blamed toxins released from silt on the bed of the shallow waterway, which was disturbed by a heavy downpour.
Now the bottom end of the drain has silted heavily upstream of the sluice at Salters Lode, near Downham Market. Reed can be seen growing in the middle of the channel, while parts of the lower reaches are also covered in blanket weed.
PAC anglian liaison officer Denis Moules, who represents pike anglers on the Lower Ouse and Fenland Fisheries Consultative, has fished the drain since boyhood.
“I would like to see it restored to its former glory,” he said. “That means silt removal from Salter’s Lode, and blanket weed removed from sections where it’s abundant. It needs re-stocking but they can’t just put fish back in if they’re just going to be lost again.”
A report compiled by the Angling Trust’s Eastern Region Fishery Forum
warns: “During the summer, levels in the Old Bedford reduce to danger levels during times of heavy irrigation. We suggest that much of this abstraction is indiscriminate and unsupervised and water stored in reservoirs is not being used by farmers.
“The situation is being made worse in that low water levels are being replenished by dirty water from the tidal Great Ouse. This silt-ridden water has once again reduced the depth in the lower reaches and the drain is now shallow and half its normal width.
“Added to this, mitten crabs have now entered the drain with the tidal water and are present in great numbers.”
Regional chairman Kelvin Allen said trust officials hoped to bid for government funding to restore the Bedford. Clubs which control fishing on the drain want dredging to be carried out from Salters Lode towards Welney, restoring depths to 6ft.
They are also calling for an investigation into abstraction by farmers and whether levels could be replenished from other sources than the tidal Ouse.