Brown-Trout-1200x675 No Cause Found in Blackwater Fish Deaths

No definitive cause has been identified for the mass fish deaths on the River Blackwater, according to a new inter-agency report welcomed by Minister of State for Fisheries and the Marine Timmy Dooley.

The summary, published by Inland Fisheries Ireland (IFI), says a short-term waterborne irritant likely entered the river up to 72 hours before the first mortalities were recorded but dissipated quickly, leaving no trace in later tests.

IFI estimates up to 32,000 salmon and brown trout were lost in the incident, which Mr Dooley described as a serious blow to local fish stocks and surrounding communities. Angling has since resumed and Uisce Éireann tests confirm drinking water remains safe.

fish-kill-in-cavan-1200x675 No Cause Found in Blackwater Fish Deaths — Mixed species, including juvenile trout, floating at the site. Credit IFI.

The investigation was led by IFI with the Environmental Protection Agency, Cork County Council, the Marine Institute, Uisce Éireann, the Department of Agriculture, Food and the Marine, the HSE, the National Parks and Wildlife Service and the Local Authority Waters Programme.

Mr Dooley, who established the group in August and chaired its meetings, said the findings highlight the need for rigorous and transparent responses to similar events nationwide.

The full report is available on IFI’s website.