Minister of State with responsibility for Fisheries and the Marine, Timmy Dooley, has urged people "not to speculate" on the potential causes of the fish kill in the River Blackwater, Co Cork.

A third meeting of an inter-agency group established to investigate the cause of fish mortalities in the River Blackwater catchment met yesterday (Wednesday, September 4).

Inland Fisheries Ireland (IFI) is ordinating the group which includes; Cork County Council, the Environmental Protection Agency (EPA), the Local Authorities Water Programme (LAWPRO), National Parks and Wildlife Service (NPWS), HSE, the Marine Institute, and Uisce Éireann.

Last month (IFI) confirmed it was investigating a large fish kill - that killed thousands - in the River Blackwater, Co Cork.

IFI has published various technical reports from the Marine Institute and the EPA in relation to lab tests, virology reports and site visits in the aftermath of the fish kill on the River Blackwater on its website.

The Department of Climate, Energy and the Environment said that the results of these reports are continuing to be examined, and "investigations are ongoing to establish the cause" of the fish kill.

"All bodies are working together to progress and advance the ongoing investigation," the department stated.

It also detailed that EPA inspectors have focused their investigation on the following EPA regulated facilities in the Blackwater catchment:

Two drinking water plants that use chemicals for coagulation and flocculation;
10 licensed industrial sites;
17 wastewater discharges - eight of which hold wastewater discharge licences and nine which hold certificates of authorisation.

The Department of Climate, Energy and the Environment also confirmed that a number of licensed sites were not in compliance with certain licence conditions during the period, which are the subject of separate enforcement actions.

"However, to date, the EPA has not identified a causal link between discharges from the EPA-regulated facilities and the fish kill," it added.

IFI, EPA, and Cork County Council are continuing macroinvertebrate sampling in the river.

IFI has also carried out a limited electrofishing -  a method used to catch fish in a quick and efficient manner - survey as part of its investigations, and is also continuing with habitat inspections in the area.

It is also waiting on the results of an analysis of 28 fish specimens to detect a potential presence of heavy metals, chemicals, or pesticides in their systems.

Results of these samples are expected next week.

Minister Dooley said he is aware "of the enormous impact this incident has had on local communities and users of the Blackwater River".

"Given the complexity and scale of this work, it is important that we are careful not to speculate on potential causes until we have all the data available to make evidence-informed assessments".