An eel fisher is to argue at the high court in Belfast that the authorities have allowed the ecological collapse of Lough Neagh by failing to take action over pollution.

Declan Conlon, whose family have for generations fished the inland lake in Northern Ireland that once hosted the largest wild eel fishery in Europe, is seeking to take a judicial review against the Department of Agriculture, Environment and Rural Affairs (Daera). He will argue the department has failed to act against polluters despite clear evidence of the ecological collapse of the lake.

Lough Neagh, the UK’s largest lake by surface area, is situated in the heart of Northern Ireland and is a globally important and internationally protected site. But it is suffering from an acute environmental crisis. It is overloaded with phosphorus and nitrogen from agriculture, including farm runoff, fertilisers and animal waste, as well as from inadequate wastewater treatment facilities and septic tank leakage.