Ely Beet Club, which controls around three miles of the Great Ouse downstream of the city, as well as former record zander water Roswell Pits, is holding what is being described as a crisis meeting on Friday, December 15.
In a letter to members, secretary Elaine Pullar writes: "Your fishing section committee is made up of three volunteers and could possibly collapse due to Paul Verdon stepping down.
"We need you to come along and listen to what is being proposed by the fishing committee and the management committee. This will be your opportunity to be aware of what is being proposed.
"If the fishing committee does not get support on the evening then the management committee will have to make decisions based upon a financial impact which could affect the amount of waters being made available."
Uncertainty has surrounded the future of Roswell since it was sold to a property developer by the charity which owned it earlier this year.
Speculation is rife that parts of the pits could be transformed into a marina and the new owner has not so far commented on whether fishing has future on the water, which has produced record zander and pike nudging 30lbs in the past.