Lough Neagh, the largest freshwater lake in the UK and Ireland, is the heart of a vast interconnected aquatic ecosystem, from its surrounding catchment area to the rivers which flow into it and flow out to the north coast.
In recent years, that heart has been under increasing pressure and, in 2023, an unprecedented blue-green algal bloom appeared, causing immense public interest and which was visible from space.
In this video, we meet Adam Mellor of Agri-Food and Biosciences Institute (AFBI) and Neil Reid of Queen’s University Belfast, who explore the subject of Blue-Green Algae.
The Cyanobacteria found on Lough Neagh is a natural component of plankton and plays a vital ecological role. It produces oxygen and supports the food chain. It would typically have favoured lower light conditions and lived under the surface of the water. However, climate change, nutrient run-off from agriculture and waste water, invasive species like zebra mussels and sand dredging, have tipped the balance.
Once submerged and stable, newer species like Microcystis and Anabaena now dominate, forming toxic surface scums during warm, calm spells. Adam Mellor says that this is not unique to Lough Neagh and is a result of nutrient enrichment. He says that AFBI has also been studying what they call ‘emerging contaminants’ to determine their impact.
In 2023, the unprecedented bloom was fuelled by warming waters, still weather, and decades of nutrient build-up in lakebed sediments. These blooms not only threaten aquatic life but the ‘sludge’ presents a real risk to human and animal health, producing harmful toxins and hosting dangerous bacteria like E. coli and salmonella.
Neil Reid says that some of the toxins found were “exceeding the World Health Organisation recreational exposure limits.”
Scientists from Queen’s University and AFBI have been studying Lough Neagh since the 1960s but since the recent algal bloom, Neil Reid says there has been a ‘ramping up’ of research.
Current research by PhD students includes satellite tracking of bloom history, molecular genetics, ecological modelling, and the exploration of nature-based solutions like reforestation, wetland restoration, and riparian buffers, to reduce nutrient run-off.
What is at stake is more than just water quality. It’s the resilience of our ecosystems, the future of our agriculture, our wellbeing, and the environmental legacy we leave for the next generation.
Lough Neagh is not just a lough, it’s a reflection of how we care for the land, the water, and each other.
Adam says that we need to get to a “good ecological integrity”.
The views and opinions on the subject of this video are that of the contributors.
