More than 500 fish found dead in River Tolka as investigation continues

Authorities are investigating a significant fish kill on the River Tolka after more than 500 fish were found dead along a 2km stretch of the waterway near Damastown.

Inland Fisheries Ireland (IFI) is leading the investigation in conjunction with a number of State agencies after receiving a report through its confidential hotline on Saturday, August 1.

Fisheries officers responded immediately and carried out an inspection of the affected stretch of river.

Early indications suggest more than 500 fish have died, although the full extent of the incident has yet to be confirmed.

Among the species found dead were brown trout, eel, stickleback, lamprey and minnow.

The discovery has prompted a coordinated investigation involving several environmental agencies as efforts continue to establish the cause of the fish kill.

Water samples have been taken from the river and will now undergo laboratory analysis. Investigators are working to determine what led to the incident, although no official cause has yet been identified.

IFI is coordinating the response under the recently introduced national interagency protocol for investigating significant fish kills, which is designed to bring together the relevant authorities during serious environmental incidents.

An interagency group was convened on Sunday, August 2, involving representatives from the Environmental Protection Agency, Fingal County Council and the National Parks and Wildlife Service.

According to IFI, the group has since completed its role after establishing a definite line of enquiry, with the investigation continuing under the relevant authorities.

Fish kills can have a significant impact on river ecosystems, affecting not only fish populations but also the wider aquatic environment.

Investigators will seek to establish both the source of the pollution and any potential long-term effects on the affected stretch of the Tolka.

IFI has not released further details regarding the line of enquiry while the investigation remains ongoing.

The agency is urging members of the public to report fish kills, water pollution, habitat destruction or illegal fishing through its confidential 24-hour hotline on 0818 34 74 24.

Anyone who notices signs of pollution or distressed wildlife in rivers, lakes or coastal waters is encouraged to report the matter as quickly as possible to assist investigators.