Investigators hope the results will reveal what chemicals caused one of the largest fish kills in the history of the State.
The disaster, along a 40km stretch of the River Blackwater in north County Cork, was initially believed to have been caused by a bacterial infection.
But Inland Fisheries Ireland (IFI) and the Marine Institute have since suggested that a toxic chemical spill may have caused the fish kill.
An independent senior scientist, brought in by affected fishing clubs, has already concluded that the likely cause is “run-off” from an industrial chemical or agricultural spill.
One of the fish affected by the recent fish kill in the River Blackwater. The fish would seem to be blind and cannot feed as a result. Picture: Dan Linehan
Sue Mitchell, a senior scientist who is EU-accredited for her work, presented her findings to fishing clubs at a meeting held in Mallow attended by local angling groups last Friday.
The decimation of fish along the Blackwater Valley includes game fish such as salmon and trout.
Endangered species such as the EU-protected freshwater pearl mussel and lampreys are also said to have been killed.
The IFI has since said in a statement that lesions on the fish indicate an “environmental irritant” caused problems to the ‘gills, skin and eyes’ of the dead fish.
The fishery protection authority said that, to date, the Environmental Protection Agency (EPA) has not raised concerns about water quality along the main river and its feeder tributaries, but more water quality results will be available soon.
Preliminary tests on fish samples have so far showed no evidence of bacterial infection or systemic disease.
The meeting last Friday was attended by Minister of State for Fisheries and the Marine, Timmy Dooley, senior advisors, IFI acting chief executive Suzanne Campion, the EPA and local IFI staff.
The IFI has since said virology results will be available towards the end of August and that testing to date indicates some form of “environmental irritant” is likely to be responsible.
The incident affected a section of the River Blackwater about 20km either side of Mallow, in North Cork.
The Munster Blackwater in Mallow, Co Cork. Picture: Dan Linehan
Any potential spill is believed to have entered the River Blackwater, via the River Allow.
That tributary was last year the subject of a fish kill that led to the deaths of 5,000 fish.
The fish species affected included Atlantic salmon and brown trout.
The IFI later took a successful legal case against Uisce Éirean after it was discovered 2,500 litres of polyaluminium chloride were released into the river accidentally from a burst pipe at the utility’s water treatment plant in Freemount.