An investigation is taking place into the cause of serious pollution of an important angling river and lake in Co Clare which has destroyed up to 20,000 fish, ranking it among the worst fish kills of recent months.
An estimated 15,000 to 20,000 fish have been destroyed on Cull aunyheeda lake, known locally as Cullaun lake, and the entire nine-mile stretch of the Rinne river, which flows into the Fergus estuary on the Shannon.
The discovery of dead fish was first made on Monday. It coincided with a major algal bloom on the lake, which flows into the river. All fish life on the river and lake was wiped out over following days and, according to fishery experts, it could take up to three years before stocks recover.
This is a popular area for anglers and the local economy has benefited from such tourism. Local angling associations, with the assistance of the Shannon Regional Fisheries Board, had restocked the lake in recent of years.
The board is investigating possible causes and monitoring the condition of the water. Its chief officer, Mr Eamon Cusack, said: "We initially allow natural means to regenerate fish stocks."
This was, he said, a clean river which had no problems before. "The lake is used as a mixed fishery and the river is not as big as the Mulkear [in Co Limerick], where there was a recent fish kill, but nevertheless it's a disaster for the local economy."
The kill could be due to enrichment of the lake which with weather conditions could have caused the algal bloom through eutrophication. Nutrient run-off from the surrounding catchment area from agricultural sources, often due to over-fertilisation of land, or domestic use of phosphate-rich detergents which can contaminate ground water, may have had an impact on the water system.
The enrichment problem nationally has prompted the farm advisory body, Teagasc, to launch a campaign against the dangers of excessive fertiliser use. A spokesman for Shannon Development said yesterday it regretted any incidents which would damage angling and its contribution to tourism. "We would advise farmers to listen to the programme currently being undertaken by Teagasc to protect our waterways," he said.
The chairman of the Cullaun District Anglers Association, Mr Joe Brady, said it was unbelievable that this could happen. "It's most disappointing as we have restocked it and only recently a 7 1/2lb trout was caught in the lake, part of a chain of lakes we have done work on." Summer algal blooms in waters in the area were the worst he had seen. "This sets us back to zero and it's going to take years to recover."
Mr Jackie McHugh, chairman of the East Clare Angling Group, the umbrella body which promotes the area as East Clare Lakelands, said it was regrettable as it was difficult to get anglers to come to east Clare. "We spend a lot of money promoting the tourism potential of the area and this particular 400-acre lake was also very good for pike fishing.".