Inland Fisheries Ireland estimates that more than 20,000 fish have died on the River Glyde in County Louth. The assessment, reported by multiple outlets, indicates that a large number of fish were killed in the incident on the river. The reports do not provide details in the excerpts about the cause of the fish deaths, the timeframe over which they occurred, or whether investigations are ongoing. The figures are presented as an estimate rather than a confirmed count, suggesting authorities are assessing impacts based on available evidence. Both sources describe the same location and scale of the event, with the Belfast Telegraph and RTE News citing the Inland Fisheries Ireland estimate. The incident is significant due to the number of fish affected, and it highlights the need for further information on environmental conditions on the river and any follow-up actions by relevant authorities.