Belfast Lough is on a 'knife edge' due to a failure to invest in wastewater infrastructure, MLAs have been warned.

An alarm bell was sounded over the state of waste water infrastructure in Northern Ireland and the impact on waterways.

A competition has been launched to find solutions to predict, detect and monitor the extent and movement of the noxious blooms on the lough.

Infrastructure Minister John O’Dowd said drinking water was being impacted by increased algae levels in Lough Neagh.

Minister Andrew Muir met with stakeholders following the publication of a Lough Neagh Action Plan.

The Earl of Shaftesbury, who owns the lough bed, met Environment Minister Andrew Muir as blue-green algae blooms returned to the lake this year.

Noxious blooms covered large parts of the lough last summer.

The North's Environment Minister Andrew Muir issued the warning to the Assembly.

Andrew Muir spoke out during a visit to the lough with First Minister Michelle O’Neill and deputy First Minister Emma Little-Pengelly.

Noxious blooms covered large parts of Lough Neagh last summer, and also affected other waterways and beaches in the region.

Andrew Muir made the announcement during a debate on an Assembly motion calling for action to protect Lough Neagh

The head of the Northern Ireland Environment Agency said there was no quick fix to the problem, which is impacting Lough Neagh.

SDLP Assembly leader Matthew O’Toole submitted the motion on Tuesday, saying the algae growth on the Lough is ‘a catastrophe’.