THE WESTERN Regional Fisheries Board (WRFB) says it is investigating the cause of a significant fish kill last week near Ballintubber Abbey, Co Mayo. Three fish kills within seven days have also been recorded by the Shannon Regional Fisheries Board (SRFB).
The WRFB says "hundreds" of juvenile trout and other aquatic life have been "wiped out" on a 500-metre stretch of the Ballintubber stream near Ballintubber Abbey.
The kill occurred last week in a feeder stream of Lough Carra, which is a special area of conservation and part of the three great western lakes.
The board says that no source has as yet been confirmed, but it is making a special appeal to farmers and contractors to be "vigilant", particularly with silage-making.
The SRFB has made a similar appeal, warning that pollution can be a "silent killer", particularly in hot weather when water levels are low.
SRFB chief executive officer Eamon Cusack has called on farmers to be "especially careful" to prevent seepage from pits during the silage-making season, and has asked industries and other bodies licensed to discharge to waters to "increase their vigilance".
SRFB staff have been alerted to several fish kills since June 5th, when adult brown trout were killed in a tributary of the Glencorbry river, which flows through Glin village, Co Limerick. Samples have been taken for possible prosecution, and the SRFB believes the kill may have been caused by agricultural effluent.
A second kill was reported on June 6th, near the village of Kilmurry McMahon, Co Clare, in a tributary of the Crompaun river, which flows into the Shannon estuary. A large number of brown trout and eels perished over several miles of river, wiping out the main fish stocks. Agricultural effluents are also believed to have caused the pollution, and the fact that eels died indicates that the pollution was "particularly noxious", the board says. Eels are known to be a "pollution-tolerant" fish species, it points out.
A third fish kill occurred in the Drumcamoge river, a tributary of the river Maigue on June 8th. Samples were taken from wastewater treatment works and are being analysed, the board says.