Sinn Féin MEP Liadh Ní Riada is urging people and businesses to exercise the appropriate caution when using or disposing of poisonous chemicals.
The Ireland South MEP, who sits on the EU Fisheries Committee, was speaking after a major fish kill in Tipperary.
Nearly 15,000 fish were killed, including more than 10,000 protected Lamprey, in the Ollatrim River, a tributary of the Nenagh River, in a suspected chemical poisoning.
“A fish kill of this size is a tragedy for any area,” she said.
“Our beautiful waterways are such a crucial part of our countryside, especially when it comes to attracting tourists and anglers and incidents like this can deal a serious blow to local economies.
“It is especially tragic given that Lamprey are a protected species and it will take the population several years to recover.
“The cause of the fish kill is being investigated but in the meantime I would urge any person or business using or disposing of dangerous chemicals to exercise all possible caution when it comes to avoiding contamination of our waterways.
“Make sure herbicides, pesticides or any other such materials are being mixed, sprayed or used well away from any water courses and that they are appropriately diluted to avoid being needlessly strong.
“Incidents like this can be easily avoided if we all take it upon ourselves to protect our rivers, our environment and our communities.”