This is a summary report of water samples taken by DAERA as part of the Bathing Waters programme during the blue-green algae events of recent months.
Approach and Findings
The report provides the background to the monitoring approach taken at identified and candidate bathing waters by the department and a timeline of sample testing and actions during the recent blue-green algae events at Lough Neagh and the north coast.
The approach and the findings will now be reviewed by DAERA along with external scientific experts and stakeholders to inform the next steps and best methodology for 2024.
It should be stressed that the blue-green algae events that we witnessed during the Summer and Autumn months were unprecedented and required a new operational protocol to be urgently developed by both DAERA and NIEA officials to deal with the matter. A multi-agency approach was also quickly adopted to tackle the issue.
Whilst this was a first for Northern Ireland, blue-green algae is a frequent occurrence in other parts of the world, therefore, DAERA drew on the experience and approaches taken by other countries as well as World Health Organisation (WHO) guidelines to inform our actions.
At all times DAERA acted in the interests of public health when giving advice against bathing at the sites that the Department monitors. In some cases, this advice was given as a precautionary measure before results were confirmed.
Accredited Testing
Samples were tested by fully accredited laboratories and give a breakdown of cell counts and cyanotoxin concentrations. On occasions levels are significantly above WHO recommended guidelines. More work needs to be done to find out why this is the case.
The Department is also very aware that we are likely to face similar problems with blue-green algae in future years and so there is work being done now to explore short, medium and long-term actions.
In addition, a monitoring programme will consider the winter dormancy and early spring period for blue-green algae and associated cyanotoxins to understand the die-back phase of a blue-green algae bloom and any related baseline cyanotoxin levels, as well as to better understand the ecology.
A long-term monitoring programme will also be developed but until then NIEA, which currently monitors and tests 450 rivers and 21 lakes, will continue to test for blue-green algae as part of the Water Framework Regulations.
And both NIEA and DAERA will continue the programme of engagement with key stakeholders to help find ways to tackle this complex and multi-factorial issue, which will likely take decades to solve.
Summary of blue-green algae monitoring in Northern Ireland bathing waters 2023