Inland Fisheries Ireland expands search into River Blackwater fish kill cause
One of the fish affected by the recent fish kill in the River Blackwater, Co Cork. The fish would seem to be blind and cant feed as a result. Picture: Dan Linehan
Inland Fisheries Ireland has expanded its search for the cause of Ireland’s largest fish kill.
In a statement issued on Tuesday evening, it said staff had completed more than 110 habitat inspections at 45 locations since the incident was reported on August 11.
Staff are now conducting additional inspections on the River Blackwater to assess the scale of mortalities and the waters affected.
They are also using drones and kayak patrols over an extended stretch of river to survey the scene.
The has learned the IFI ordered “a full suite of testing” for 900 chemicals in addition to standard heavy metals.
An email seen by anglers concluded: “ideally, the results will narrow down the focus of the investigation” and provide a basis for further testing.
Residue test results are due to be delivered to IFI on Wednesday and will be published after inter-agency review.
The body stated: “(IFI) continues to investigate the large fish kill on the River Blackwater — and is further deploying a range of operational activities to try to find a cause.
“It 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.”
They added: “The results of the latest analysis may direct further steps in the investigation.”
Diagnostic testing of fish samples by the Marine Institute on August 14 found no evidence of bacterial infection, systemic disease, viral infection, or specific parasites.
However, consistent gill pathology suggested possible chronic exposure to a chemical agent.
This indicated the event likely occurred days before the first report reached IFI, the fisheries watchdog said.
IFI has previously stated the cause of the massive fish kill was “an irritant in the river.”
Independent tests by an experienced scientist concluded unequivocally that the fish kill resulted from a chemical or toxin discharge.
The published results from this analysis, which showed some fish suffered severe deaths, including rotting flesh and eyes bursting from their sockets.
The fourth meeting of an inter-agency group was held on Monday. Led by Inland Fisheries Ireland, the group includes the Environmental Protection Agency, Cork County Council, and the Marine Institute. It was established to determine the cause of the River Blackwater fish kill.
In addition to widening its search, IFI is also estimating the number of fish killed using historic population records.
