Northern Ireland Faces Alarming Rise in Toxic Algae Blooms

New Delhi, India Jul 26, 2026 ALN: As locals and visitors make the trip to Northern Ireland's lakes in search of summer sunshine, they are once again facing an unwelcome sight: blue-green algae.

The toxic bacteria, which can cause skin irritation and sickness in people and animals who come into contact with it, has become an unwelcome feature of recent summers. The resurgence of blue-green algae, also known as cyanobacteria, is a growing concern not only for public health but also for the ecological balance of Northern Ireland's freshwater systems.

There are currently 248 algae blooms across Lough Neagh and Northern Ireland's water systems, according to the UK Centre for Ecology and Hydrology. Eighty have been confirmed in June and July alone, indicating a troubling trend that has been observed in recent years. The Department of Agriculture, and Rural Affairs (Daera) has reported that two of the areas affected were Camlough Lake near Newry and Craigavon Lakes. This increase in blooms is likely linked to a combination of factors, including climate change, agricultural runoff, and nutrient pollution.

For one business owner based at Camlough Lake, the return of blue-green algae has had an immediate impact on local commerce. Karl Toner, who owns a coffee cart on the shore as well as a nearby glamping site and paddleboard hire business, stated that visitor numbers had fallen sharply since the warning was issued on 13 July. "In the summertime this place really goes off; now the algae has just completely killed it," he said. Toner explained how warm weather would normally bring visitors from across Northern Ireland and beyond to the area, providing a trade boost. "On a good day, there would be hundreds of people here from the morning right through until midnight, swimming and enjoying the lake, but now the place is empty," he lamented.

Toner noted that algae warnings in previous years meant visitor numbers suffered, but the timing of the current bloom was particularly damaging for footfall during one of the best spells of summer weather. "When the weather gets good, the lake is closed. It's like having an amusement park and not opening it," he said, highlighting the economic implications of the algae problem for local businesses that rely on tourism.

Newry, Mourne and Down District Council said it was notified by Daera on 13 July of the presence of blue-green algae at Camlough Lake and erected warning signs immediately to alert the public to the potential health risks. The council stated that it was carrying out regular visual monitoring of the lake and arranging toxin testing, adding that warning signs will remain in place until the required safety criteria under the protocol is met. This proactive approach is crucial in safeguarding public health, as exposure to blue-green algae can lead to serious health issues.

A Daera spokesperson acknowledged the complexity of the issue, stating that while there were "no quick fixes", restoring and protecting the ecological health of water bodies was "possible by respecting and supporting the difficult decisions needed". This statement underscores the necessity for a comprehensive strategy that involves multiple stakeholders, including government agencies, local communities, and al organizations.

'The lake is about much more than swimming'

Joanne Callan, a holistic therapist from Bessbrook, began swimming at Camlough Lake occasionally in 2018 before becoming a regular open-water swimmer during the Covid-19 pandemic. Since then, she said a community of swimmers and cold-water dippers had grown to more than 100 people, many of whom have formed friendships through a "shared love of the lake". Callan emphasized that Camlough Lake was usually a hive of activity during the summer months, with young people gathering, families playing in the shallow water, paddleboarders taking to the lake, and athletes using it as a training space during triathlon season.

She expressed concern that keeping the lake closed or restricting access during the height of summer would "impact many people, physically, emotionally and socially". The lake serves as a communal space where individuals come together to engage in recreational activities, fostering a sense of community and well-being that extends beyond mere swimming.

Blooms Spotted at Craigavon Lakes

A spokesperson for Armagh City, Banbridge and Craigavon Borough Council confirmed that watersports activities and open-water swimming at Craigavon Lakes were suspended on 21 July due to the presence of blue-green algae. The council stated that the situation was being "monitored daily", with "regular assessments of water conditions carried out in line with safety procedures". The emphasis on daily monitoring is crucial, as it allows for timely responses to changing conditions and helps ensure that public safety remains a priority.

Rachel and Tilly Turkington, from Derrytrasna, County Armagh, regularly visit Craigavon Lakes for walks and trips to the café but have avoided entering the water because of concerns over its quality. The family, who are interested in watersports and recently purchased a paddleboard, stated they would only consider using the lake if those concerns were addressed. "If this water was cleaner and there wasn't the algae issues, we would definitely bring the paddleboard here," Rachel said. On a recent walk, the pair noticed areas where the water appeared stagnant, with green patches and visible blooms. This observation reflects the broader public concern regarding the health of local waterways and their suitability for recreational activities.

Despite living close to the shores of Lough Neagh, the Turkingtons noted that recent concerns around water quality had made them more cautious around local waterways. "We take extra care and I wouldn't let the dog drink the water just in case," Rachel added, illustrating the impact of the algae problem on everyday life and the decisions families must make regarding their recreational activities.

Analysis

Any spell of sunny, settled weather will bring blue-green algae out in force, although the blooms have felt a little slow to start this year, primarily due to the weather. Algal spores may have turned the water green in places across Northern Ireland, but strong winds and heavy rain have kept surfaces too agitated for the formation of the very large-scale mats we've seen before. However, as conditions stabilize, it is likely that the blooms will return with greater intensity.

Take Lough Neagh – by scientists' estimation, approximately four decades' worth of phosphorus, the nutrient that stimulates growth, are stored in its sediment. This accumulation of phosphorus is a significant factor contributing to the proliferation of blue-green algae. Even as algae consumes that phosphorus, it is being replenished in the water by agriculture, wastewater, un-maintained septic tanks, industry, and every household in the catchment that puts phosphorus-containing detergent into the system. This cycle of nutrient pollution highlights the urgent need for comprehensive management strategies to mitigate its effects.

Addressing nutrient pollution at the source is the first point of action in tackling the problem, and that is why the big contributors – farming and water treatment – are the first port of call. Policies like the Nutrient Action Programme play an important role in this process, aiming to reduce nutrient runoff and improve water quality. However, as experts have pointed out, there is no quick fix, and few cheap or easy solutions exist. It requires a concerted effort from various sectors of society, including government, agricultural stakeholders, al groups, and the public, to work collaboratively towards a sustainable resolution to the challenges posed by blue-green algae blooms.

The implications of these blooms extend beyond immediate health concerns. They affect local economies, recreational opportunities, and the overall ecological balance of freshwater systems. As climate change continues to influence weather patterns, it is likely that the frequency and intensity of blue-green algae blooms will increase, necessitating urgent action to address the underlying causes and protect these vital water resources for future generations.