The cull will reduce the carp population of the lake from 165 to 65
Fishermen who are strongly opposed to a planed cull of fish at a lake in Bristol have threatened to chain themselves to the entrance gates.
Henleaze Lake in an old quarry is shared between an exclusive swimming club and the anglers.
The club's committee proposed the cull saying it would greatly improve the water clarity.
Environmental experts are to be paid £7,000 to be brought in on Monday to exterminate hundreds of the carp.
An electric current will be passed through the water forcing them towards nets.
Small fish will be removed and the total population of the carp will be reduced by more than half from 160 to 65.
The Environment Agency which supports the cull said the carp cannot be moved to another lake as they have a parasite in their gills which would infect other fish.
Heather Bourne, whose father fishes at the lake said: "Some of the fishing members are deeply distressed and are threatening to chain themselves to the fence."
"I think something needs to be done and in the long run I think it will improve the angling but what they're proposing, to take out so many fish, I think they've got their figures wrong," said one angler who asked to remain anonymous.
"I do feel annoyed but it won't do any good," he said.
Mark Thompson, who is a swimming club executive member, said the lake currently has 11 times the stocking level recommended by the Environment Agency.
"We're taking out two tonnes of fish, leaving the 65 best carp so after the stock reductions we will have about three tonnes of fish in the lake," he said.
"This will still make us about six times overstocked but the strategy is to leave a high proportion of pike and perch which will further reduce the stock."
The lake was last destocked in the late 1980s.