Lough Neagh, which covers nearly 400 km² in area in the centre of Northern Ireland, supports agriculture, fisheries and is an internationally important wetland for wildlife. It is also the source of around 40 per cent of the country's drinking water.

However, the lake and rivers linked to it are polluted by excess nutrients, including run-off from farms and industrial sources and wastewater treatment works.

Algal blooms in recent years – particularly a major outbreak in 2023 that caused the death of wildlife and the closure of recreational and fishing areas - have highlighted the urgent need for tools to better identify the sources and movement of pollution across the catchment.

There is also threat of the spread of antimicrobial resistance (AMR) in the environment that can pose risks to ecosystems, livestock and human health.

The UKCEH-led project, which also involves Biota Trace and the Lough Neagh Partnership, will use advanced scientific methods to trace pollution across the Lough Neagh catchment including tributaries, inlets and the shoreline. The investigation is being funded by the National Environment Research Council (NERC) and the Department of Agriculture, Environment and Rural Affairs (DAERA).

Dr Susheel Bhanu Busi, Head of Molecular Ecology at UKCEH who is leading the project, said:

“To address the significant challenges of water pollution at Lough Neagh, we need evidence-based science that is capable of disentangling the complex mix of microbes and chemicals that influence water quality across the catchment.”

“Traditional monitoring approaches have been unable to fully resolve how human, agricultural and wildlife sources can cause microbial contamination or capture the dynamics of AMR that can pose risks to ecosystems, livestock and human health.”

The researchers will use advanced microbial source tracking and environmental DNA (eDNA) techniques. They will also use state-of-the-art technology, including automated high-frequency sampling and autonomous unmanned survey vessels to collect samples in areas that are otherwise difficult or unsafe to access.

By analysing DNA from water collected across the lake, its tributaries and outflows, the team will be able to discover whether the source of contamination is human, agricultural or wildlife.

Data will be integrated with catchment models and hydrological information to produce summaries and high-resolution maps of pollution sources, seasonal patterns and key risk pathways.

The information will be available via an online science platform which will help the Lough Neagh Partnership and other stakeholders see patterns, trends and risks, rather than having to interpret technical datasets themselves. This will support the restoration and long-term care of the lake.

Designated as an Area of Special Scientific Interest, Lough Neagh’s habitats support rare fish, birds and plants. It is also the source of drinking water for hundreds of thousands of people, though NI Water says its treatment techniques are designed to deal with algae to make water safe for customers.

The CLEAR-Neagh project (Catchment-Level Environmental AMR & eDNA Reconnaissance for Lough Neagh) will start in March and run for 18 months. It is part of the £9m UK Freshwater Quality Programme, which is investigating how pollution affects water quality in lakes and rivers. This programme is led by the University of Leeds and funded by NERC and Defra.