Fish kill probe continues
The huge fish kill in River Blackwater is still being investigated and a range of operational activities have been deployed to try to find a cause.
Inland Fisheries Ireland (IFI) has sent 28 brown trout specimens for extensive laboratory testing, from an affected stretch of the river, to identify any contaminants in their bodies.
This residue testing is checking for the presence of a variety of potentially harmful substances in their systems – including heavy metals, chemicals, and pesticides.
The results of the latest analysis may direct further steps in the investigation.
It follows on from the diagnostic testing of fish samples conducted by the Marine Institute on 14 August.
An IFI spokesperson confirmed: “A key finding from the Marine Institute was that there was no evidence of bacterial infection, systemic disease, specific viral infections, or a specific parasite noted in test samples. However, gill pathology was consistent across the samples and suggested possible chronic exposure to a chemical agent. This indicated that an event had happened in the days before the first report was made to IFI.”
IFI’s operational and scientific staff are also carrying out further habitat inspections on the River Blackwater to assess the scale of mortalities, and waters affected. More than 110 habitat inspections at 45 locations have been completed since the report of the fish kill on 11 August. Staff are deploying drone and kayak patrols over an extended area of river channel to continue to examine and survey the scene as well as quantifying the number of fish that may have died in the incident using historic population records.
Staff are also undertaking a survey of juvenile lamprey - freshwater fish species that live in the river sediment - to assess the status of this protected species in the catchment.
The spokesperson added: “Mortalities observed by IFI were included in a mixture of healthy and sick fish throughout the affected channel, and were predominantly brown trout. IFI's investigations are being executed in collaboration with other statutory partners.”
A fourth meeting of an inter-agency group arising from the River Blackwater incident took place on Monday.
Residue test results were sent to IFI on Wednesday, and will be published following an examination of the data by members of the inter-agency group. Clubs and fishery owners will be contacted individually by IFI staff regarding assessments of the effects of the fish kill.