Inland Fisheries Ireland (IFI) says it is investigating a “significant” fish kill incident on the Crover River in Co Cavan, which is a tributary of Lough Sheelin.
Officers from the Shannon River Basin District became aware of the incident late on Friday evening (12 August).
And IFI estimates that there could be in excess of 1,000 juvenile trout killed in the incident, covering a 1.5 km stretch of water.
Other aquatic species were also found dead, such as crayfish, lamprey, stone loach and invertebrates.
IFI says is not in a position to confirm the cause of the fish kill while investigations are ongoing.
Previously the State agency responsible for the protection and conservation of freshwater fish and habitats warned of a high risk of fish kills due to thermal stress and reduced oxygen levels in lakes and rivers amid the recent heatwave.
