A pollution incident occurred on Wednesday at Tievenny Burn, a tributary of the River Derg between Ardstraw and Victoria Bridge in County Tyrone. Local anglers reported the effluent spillage to authorities.

Brendan Winters, a fisherman from Sion Mills and member of the Foyle Association of Salmon and Trout Anglers, spotted the pollution and is surveying the river with his brother for dead fish. The site lies a short distance upstream from a drinking water abstraction point.

Winters stated that juvenile salmon, known as smolts, face high vulnerability at this time as they prepare to migrate to sea. He noted potential impacts on fish, aquatic insects, and other river life, with effects to be assessed over coming hours and days.

The Northern Ireland Environment Agency received the report at 09:30 BST on Wednesday. The Loughs Agency is leading the investigation in the Foyle catchment area, with NIEA support. Fishery officers from the Loughs Agency attended the scene.

The Department of Agriculture, Environment and Rural Affairs confirmed a significant effluent spillage to the River Derg. Winters called for stronger penalties against polluters and highlighted risks from repeated incidents.

Salmon populations in rivers like the Derg, Strule, and Mourne have declined over the past two decades. The Derg supports spawning salmon, brown trout, and sea trout.