The deaths of two Labrador dogs after a swim in Lough Derg have prompted Clare and North Tipperary County Councils to ban the public from swimming in the lake.
A subsequent investigation of the waters in the Youghalarra area of Lough Derg where the dogs swam found a potentially toxic algae bloom.
The councils have now erected signs advising the public not to swim in the lake, and farmers and others to keep domestic and farm animals away from it.It is the fifth year in a row that the councils have erected such signage along the Shannon's largest lake.
A spokesman for North Tipperary County Council said yesterday: "The notices have been circulated as a precautionary principle. The dogs died so quickly after swimming in the lake that it is thought unlikely that it was as a result of the algae bloom. "One dog died within an hour of swimming in the lake, while the second dog died not long after.
"There was also a Doberman with the Labradors and the dog owner said that he did not enter the lake, which does heighten our level of anxiety."
The spokesman said that children be kept away from the shoreline as contact with the scum may cause irritation. Dog owners should also keep their pets away from the water and shoreline scums.
He said the preliminary results of postmortems on the dogs and related toxicity tests have proven inconclusive, and the results of final tests were expected very shortly. The initial tests on the green-blue algae bloom showed there was no toxicity. The final results are expected today.
He said the Environmental Protection Agency's most recent report on water quality in Lough Derg had identified continued improvement in its water quality.
"The lake has had no toxicity in the algae bloom over the past two years."
Fianna Fáil councillor in east Clare Tony O'Brien said yesterday: "This is the fifth year in a row that such notices have been made, and it is very worrying that the source of this pollution has not been eradicated. The Shannon is our greatest amenity, and it will greatly affect the locality if that amenity can't be used to its full potential."
