Agriculture accounts for majority of fish kills with most happening in Cork and Cavan

A fish kill in the River Rye in Leixlip, Co Kildare, in 2022. Salmonids were the main fish group affected during the period, with brown trout and salmon the main species affected. File picture: Inland Fisheries Ireland

Cork and Cavan have had the highest proportion of fish kills over the last half century, with agriculture the most commonly known cause, a vast new study shows.

Agriculture, eutrophication — when nutrient enrichment depletes oxygen in the water — industry and municipal activities are the most common causes of the more than 2,100 recorded fish kills in Ireland between 1969 and 2022. Rivers were the most impacted waterbody followed by lakes.