Water discolouration and fish deaths at Crawfordsburn Country Park were caused by natural conditions, not pollution, according to the Northern Ireland Environment Agency.

Local residents and dog walkers had raised concerns after noticing the river feeding onto the beach had turned green and contained dead fish. NIEA inspectors attended the site and found no evidence of pollution.

A spokesperson said a sandbar at the stream outlet, combined with vegetation and seaweed, reduced water flow and oxygen levels. Warmer water temperatures also contributed to the fish deaths. Conditions further upstream were normal.

Further inspections confirmed no pollution was present, and NIEA will continue to monitor the situation.

Andrew Muir, Minister for Agriculture, Environment and Rural Affairs, said he continues to work on tackling pollution and improving water quality across Northern Ireland. He cited new legislation to strengthen fines, changes to NI Water provisions, a special designation for Inner Belfast Lough shellfish water, and new Nutrients Action Programme regulations.

Councillor Lauren Kendall said the latest information suggested the discolouration was linked to decomposing seaweed trapped by sand at the river mouth rather than a pollution discharge. She said it highlighted the poor state of Northern Ireland waterways and a lack of proactive management.

Kendall thanked local residents and walkers who raised the alarm. She said people are right to be concerned when they see discoloured water and dead fish, given the lack of action to protect rivers and coastal ecosystems.

Anyone wishing to report a water pollution incident can call the 24-hour Incident Hotline on 0800 807060.