Pike anglers are at the forefront of the fight to save Cambridgeshire's ancient lodes.
The historic waterways, which date back to the Romans, are in a "new" plan by the National Trust to extend the Wetlands of Wicken Fen. This will involve transforming them into internal drainage ditches.
Pike Anglers Club liaison officer Dennis Moules said: "We successfully fought this issue 30 years ago. This is completely unacceptable for all anglers.
"The Lodes hold specimen fish of all species and are ideal waters on which to teach youngsters.
"I urge all anglers to support this cause by signing the online Don't Ditch Our Lodes petition to No.10 Downing Street, by clicking here."
One of those for whom the lodes hold special memories is Ian Moules, who learned to fish on their banks, He is pictured above with a 22lbs pike caught from one of them .
The petition reads simply: "We the undersigned petition the Prime Minister to ensure that the Cambridgeshire lodes don't get ditched!"
Dennis added: "Geoffrey Woollard, a retired county and district councillor, is coordinating opposition to this plan, but we need help from as many anglers as possible.
"The Lower Great Ouse and Fenland Fisheries Consultative Committee, on which I serve, are to oppose this at the highest level."
Mr Woolard writes in his introduction: "Some 30 years ago, a successful campaign was waged to save The Cambridgeshire Lodes, ancient canals of probable Roman origin - principally Bottisham, Swaffham Bulbeck, Reach, Burwell and Wicken Lodes - which were threatened by the then authorities.
"A decision was made to maintain and to preserve The Lodes. Such is the situation today: The Lodes have been maintained and preserved.
"But new documents indicate that The Environment Agency has commissioned a ‘scoping report’ costing some £200,000 and that it is looking critically at The Lodes, an option again being that of converting all or some of them into ditches.
"The old campaign slogan - ‘Don’t Ditch Our Lodes!’ - is just as relevant now as it was in the 1970s.
"A new factor is the National Trust’s plans to buy up and partially to flood some 10,000 acres of rich fen land and the Trust says that ‘lowering’ some of The Lodes would be ‘acceptable.’
"Lowering is much the same as ditching. The Swaffham Internal Drainage Board and Swaffham Prior Parish Council support the Lodes being maintained.
"But the Philistines could be triumphant if their opponents are inactive. So, this is a call to those with influence to use it!"