The entire length of the Threemilewater River in Whiteabbey has been affected and will take years to recover, according to local anglers.

Threemilewater Conservation and Angling Association said they had received word from a member of the public that fish had been found dead on the river on February 25.

In a follow-up search on Sunday, club members discovered more 70 dead fish, aged one year up to four years, including a lot of salmon fry and brown trout.

Bailiffs carrying out further investigations found hundreds of fish dead or dying along the river from Mossley Mill to the sea at Whiteabbey.

The club said the most severe pollution was in the head waters where adult fish had spawned.

Chairman John Webster said the fishing season starts on March 1 and there are no fish left in the river for members to catch.

"It is going to take at least four years to get the fish stock back," he said.

The fish are floating belly up along a two-and-a-half mile stretch of the waterway and are dying a slow death, Mr Webster said.

Mr Webster said the enhancement work carried out on the river over the past five years had won recognition in the form of a Wild Trout Trust Enhancement Award, carrying a £1,500 grant.

The club had steadily improved the river by installing seven new groynes and up to 400 tonnes of spawning gravel to encourage salmon and brown trout to spawn.

The judges were particularly impressed by the fact that the enhancement works had been carried out on an urban waterway following through housing estates in Newtownabbey, he said.