FOREST Enterprise is draining and netting a pool to remove diseased and stunted carp which are playing havoc with the wildlife.
Woorgreen Lake near Speech House, created in the 1970s after opencast coal mining ceased, mysteriously acquired a head of carp, said Review wildlife expert Ivan Proctor.
"Originally, it quickly colonised with native wildlife and in a few years had become a haven for birds and especially freshwater insects," he said.
"Dragonflies were there in uncountable numbers and from there they were enriching many other Forest ponds. Hobbies, a migrant falcon that feeds on insects, were regularly seen."
Then came the carp, he said, and with no predators they flourished, growing and breeding rapidly.
"As they devoured the vegetation that had colonised the lake the wildlife plummeted. Very few birds are seen now and the insects are a fraction of what they were in both variety and numbers.
"Even the fish, which are diseased, are restricted in their growth by the lack of food left in the lake."
To remove the fish Forest Enterprise workers have dropped the level of the lake and swept it with nets. However this has not taken a satisfactory number of fish and there are now plans to bring in pumps to drop the level still further to assist the netters.
"There could be no more salutory lesson to show that introducing any new species into the countryside is something that should never be done unless there is a very pressing reason for doing so," said Ivan.